U.S. patent application number 12/751853 was filed with the patent office on 2011-01-13 for system communication systems and methods for electric vehicle power management.
This patent application is currently assigned to GridPoint, Inc.. Invention is credited to Seth W. Bridges, Joby Lafky.
Application Number | 20110007824 12/751853 |
Document ID | / |
Family ID | 42982790 |
Filed Date | 2011-01-13 |
United States Patent
Application |
20110007824 |
Kind Code |
A1 |
Bridges; Seth W. ; et
al. |
January 13, 2011 |
SYSTEM COMMUNICATION SYSTEMS AND METHODS FOR ELECTRIC VEHICLE POWER
MANAGEMENT
Abstract
A system and method that minimizes network traffic consumption
in a power flow management system is described. A minimization
system may include a network to communicate device information and
power flow information between the power flow management system and
the devices. The power flow management system reduces consumption
of the traffic traversing the network via a network traffic
consumption reduction technique. In addition, this application
discloses a system and method for communications protocol
translation in a power flow management system that includes
networks which connect electric devices and electric power
supplies. One network utilizes a communications protocol that is
different from the communications protocol utilized by another
network. A communications protocol translation device communicates
with the networks, and formulates messages from one communications
protocol to the other communications protocol. The reformulated
messages pass from one network to another network.
Inventors: |
Bridges; Seth W.; (Seattle,
WA) ; Lafky; Joby; (Seattle, WA) |
Correspondence
Address: |
GREENBERG TRAURIG, LLP (DC/ORL)
2101 L Street, N.W., Suite 1000
Washington
DC
20037
US
|
Assignee: |
GridPoint, Inc.
Arlington
VA
|
Family ID: |
42982790 |
Appl. No.: |
12/751853 |
Filed: |
March 31, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61165344 |
Mar 31, 2009 |
|
|
|
Current U.S.
Class: |
375/257 ;
307/40 |
Current CPC
Class: |
B60L 55/00 20190201;
B60L 53/18 20190201; Y02T 90/12 20130101; Y02T 10/70 20130101; Y02T
90/16 20130101; B60L 53/665 20190201; Y02E 60/00 20130101; Y04S
10/126 20130101; B60L 53/305 20190201; Y02T 10/7072 20130101; Y02T
90/14 20130101; B60L 53/65 20190201; H02J 7/00 20130101; Y02T
90/168 20130101; B60L 11/184 20130101; B60L 53/68 20190201; H02J
2300/10 20200101; Y02T 90/169 20130101; B60L 2240/70 20130101; B60L
53/64 20190201; Y04S 30/14 20130101; B60L 53/63 20190201; H02J
3/381 20130101; Y02T 10/72 20130101; Y02T 90/167 20130101; Y04S
30/12 20130101 |
Class at
Publication: |
375/257 ;
307/40 |
International
Class: |
H04B 3/00 20060101
H04B003/00; H02J 3/14 20060101 H02J003/14 |
Claims
1. A system for minimizing network traffic consumption in a power
flow management system, comprising: a plurality of devices operable
to generate, consume, or store electric energy; a power flow
management system, wherein the power flow management system manages
power flow transferred between the plurality of devices and a power
grid; and, device information and power flow information
communicated, via a network, between the power flow management
system and the plurality of devices, wherein the device information
is received by the power flow management system, wherein the power
flow information is transmitted by the power flow management
system, wherein the power flow information comprises an energy rate
command received by at least one of the plurality of devices, and
wherein the power flow management system reduces consumption of
traffic traversing the network via a network traffic consumption
reduction technique.
2. The system of claim 1, wherein the power flow management system
is centralized.
3. The system of claim 1, wherein the power flow management system
is decentralized.
4. The system of claim 1, wherein the energy rate command provides
a time and a rate of energy transfer from the at least one of the
plurality of devices.
5. The system of claim 1, wherein the energy rate command provides
a time and a rate of energy transfer to the at least one of the
plurality of devices.
6. The system of claim 1, wherein the power flow management system
determines an optimal time and rate for energy transfer.
7. The system of claim 1, wherein the energy rate command requests
an immediate flow of power at a requested level.
8. The system of claim 1, wherein the energy rate command provides
a schedule of power flow for the at least one of the plurality of
devices.
9. The system of claim 8, wherein the schedule of power flow
provides an activation time for a power flow level.
10. The system of claim 8, wherein the schedule of power flow
provides a sequence of power flow levels for activating at
predetermined times.
11. The system of claim 8, wherein the schedule of power flow is
repeated by the at least one of the plurality of devices on a
dynamic pattern or fixed pattern.
12. The system of claim 1, wherein the device information relates
to a current state of at least one of the plurality of devices.
13. The system of claim 1, wherein the device information is
related to at least one of the plurality of devices and is selected
from a group consisting of the following: an amount and a direction
of power flow associated with the at least one of the plurality of
devices; a capacity relating to the at least one of the plurality
of devices; faults or error messages; a device presence indicator
for the at least one of the plurality of devices; a scheduling
constraint; or energy consumption in a period.
14. The system of claim 1, wherein the network traffic consumption
reduction technique is a technique selected from a group consisting
of the following: data compression, data overhead reduction,
action/schedule pre-distribution, minimum change dispatch,
communication of all status changes, configurable limitations on
relevant device behavior, or non-time-critical information
bundling.
15. A system for communications protocol translation in a power
flow management system, comprising: electric devices and electric
power supplies connected via a plurality of networks, wherein at
least one network of the plurality of networks utilizes a first
communications protocol that is different from a second
communications protocol utilized by at least a second network of
the plurality of networks; a communications protocol translation
device operable to communicate with the plurality of networks,
wherein the communications protocol translation device formulates a
message from the first communications protocol to the second
communications protocol, whereby the reformulated message passes
from the first network to the second network.
16. The system of claim 15, wherein the first network connects an
electric device to the power flow management system, and wherein
the second network connects an electric power supply to the power
flow management system.
17. The system of claim 15, wherein the first network connects an
electric power supply to the power flow management system, and
wherein the second network connects an electric device to the power
flow management system.
18. The system of claim 15, wherein the first network connects an
electric power supply to an electric device, and wherein the second
network connects a second electric device to the electric power
supply.
19. The system of claim 15, wherein the communications protocol
translation device is an electric device.
20. The system of claim 19, wherein the electric device is an
electric vehicle service equipment.
21. The system of claim 15, wherein the communications protocol
translation device is located within a power outlet.
22. The system of claim 15, wherein at least one of the plurality
of networks utilizes a communications protocol selected from a
group consisting of the following: SAE2836 or ZigBee.
23. The system of claim 15, wherein the communications protocol
translation device comprises: a microprocessor; a power supply;
physical transceivers for each of a plurality of supported
communications protocol stacks; and, a software stack capable of
decoding messages coded in the first protocol to the application
level and re-encoding the decoded messages into the second
communications protocol.
24. The system of claim 15, wherein the communications protocol
translation device is located remotely from the electric devices
connected to the plurality of networks.
25. A device comprising a first transceiver adapted to be connected
to a first network supporting a first network protocol; a second
transceiver adapted to be connected to a second network supporting
a second network protocol; a translation module comprising one or
more processors programmed to execute software code retrieved from
a computer readable storage medium storing software configured to
receive, using the first transceiver, at least one application
level message in the first protocol from the first network; decode
the at least one application level message; encode the at least one
application level message in the second protocol; transmit, using
the second transceiver, the at least one application level message
encoded in the second protocol over the second network.
26. The system of claim 25 wherein the first network is a network
in a vehicle and the second network is a network providing access
to a central charge management server.
27. The system of claim 26 wherein the first protocol is a SAE2836
protocol over PLC.
28. The system of claim 27 wherein the second protocol is a
wireless ZigBee protocol.
29. The system of claim 25 wherein the translation module is
integrated into the electric vehicle service equipment.
30. The system of claim 25 the device is a self-contained box
plugged in to a power outlet.
Description
[0001] This non-provisional patent application claims priority to,
and incorporates herein by reference, U.S. Provisional Patent
Application No. 61/165,344 filed on Mar. 31, 2009. This application
also incorporates herein by reference the following: U.S. patent
application Ser. No. 12/252,657 filed Oct. 16, 2008; U.S. patent
application Ser. No. 12/252,209 filed Oct. 15, 2008; U.S. patent
application Ser. No. 12/252,803 filed Oct. 16, 2008; and U.S.
patent application Ser. No. 12/252,950 filed Oct. 16, 2008.
[0002] This application includes material which is subject to
copyright protection. The copyright owner has no objection to the
facsimile reproduction by anyone of the patent disclosure, as it
appears in the Patent and Trademark Office files or records, but
otherwise reserves all copyright rights whatsoever.
FIELD OF THE INVENTION
[0003] The present invention relates in general to the field of
electric vehicles, and in particular to novel systems and methods
for system communication and interaction between electric vehicles
and the electrical grid.
BACKGROUND OF THE INVENTION
[0004] Low-level electrical and communication interfaces to enable
charging and discharging of electric vehicles with respect to the
grid is described in U.S. Pat. No. 5,642,270 to Green et al.,
entitled, "Battery powered electric vehicle and electrical supply
system," incorporated herein by reference. The Green reference
describes a bi-directional charging and communication system for
grid-connected electric vehicles.
[0005] Modern vehicles contain a variety of subsystems that may
benefit from communications with various off-vehicle entities. As
the smart energy marketplace evolves, multiple application-level
protocols may further develop for the control of power flow for
electric vehicles and within the home. For example, energy
management protocols are being developed for both Zigbee and
Homeplug. A vehicle manufacturer may need to support multiple
physical communications mediums. For example, ZigBee is used in
some installations while PLC is used in others. Considering the
very long service life of items such as utility meters and
automobiles, the use of multiple incompatible protocols may pose an
barrier to deployment. For example, if a homeowner buys a car that
utilizes one protocol and receives a utility meter that uses
another protocol, it is unlikely that either device will quickly
replace other device.
[0006] Significant opportunities for improvement exist with respect
to communications between power grids and electric vehicles. What
is needed are systems and methods that provide for the complexity
of translating information among various protocols. In addition to
cost of translating messages, there is a cost associated with
transmitting messages across networks. As such, there is also a
need for novel communication techniques that provide for bandwidth
minimization.
SUMMARY OF THE INVENTION
[0007] In one embodiment, a system for minimizing network traffic
consumption in a power flow management system includes devices
operable to generate, consume, or store electric energy, and a
power flow management system, which manages power flow transferred
between the plurality of devices and a power grid. This
minimization system also includes a network to communicate device
information and power flow information between the power flow
management system and the devices. The device information is
received by the power flow management system. The power flow
information is transmitted by the power flow management system, and
includes an energy rate command received by a devices. The power
flow management system reduces consumption of the traffic
traversing the network via a network traffic consumption reduction
technique.
[0008] In one embodiment of a system for communications protocol
translation in a power flow management system, the system includes
networks that connect electric devices and electric power supplies.
One network utilizes a communications protocol that is different
from the communications protocol utilized by another network. A
communications protocol translation device communicates with the
networks, and formulates messages from one communications protocol
to the other communications protocol. The reformulated messages
pass from one network to another network.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The foregoing and other objects, features, and advantages of
the invention will be apparent from the following more particular
description of embodiments as illustrated in the accompanying
drawings, in which reference characters refer to the same parts
throughout the various views. The drawings are not necessarily to
scale, emphasis instead being placed upon illustrating principles
of the invention.
[0010] FIG. 1 is a diagram of an example of a power aggregation
system.
[0011] FIGS. 2A-2B are diagrams of an example of connections
between an electric vehicle, the power grid, and the Internet.
[0012] FIG. 3 is a block diagram of an example of connections
between an electric resource and a flow control server of the power
aggregation system.
[0013] FIG. 4 is a diagram of an example of a layout of the power
aggregation system.
[0014] FIG. 5 is a diagram of an example of control areas in the
power aggregation system.
[0015] FIG. 6 is a diagram of multiple flow control centers in the
power aggregation system and a directory server for determining a
flow control center.
[0016] FIG. 7 is a block diagram of an example of flow control
server.
[0017] FIG. 8A is a block diagram of an example of remote
intelligent power flow module.
[0018] FIG. 8B is a block diagram of an example of transceiver and
charging component combination.
[0019] FIG. 8C is an illustration of an example of simple user
interface for facilitating user controlled charging.
[0020] FIG. 9 is a diagram of an example of resource communication
protocol.
[0021] FIG. 10 is a flow chart of an example of a bandwidth
minimization technique.
[0022] FIG. 11 is a flow chart of an example of a protocol
translation system.
[0023] FIG. 12 is a block diagram of an example of a communications
protocol translation device.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0024] Reference will now be made in detail to the embodiments of
the present invention, examples of which are illustrated in the
accompanying drawings.
[0025] Overview
[0026] Described herein is a power aggregation system for
distributed electric resources, and associated methods. In one
implementation, a system communicates over the Internet and/or some
other public or private networks with numerous individual electric
resources connected to a power grid (hereinafter, "grid"). By
communicating, the system can dynamically aggregate these electric
resources to provide power services to grid operators (e.g.
utilities, Independent System Operators (ISO), etc).
[0027] "Power services" as used herein, refers to energy delivery
as well as other ancillary services including demand response,
regulation, spinning reserves, non-spinning reserves, energy
imbalance, reactive power, and similar products.
[0028] "Aggregation" as used herein refers to the ability to
control power flows into and out of a set of spatially distributed
electric resources with the purpose of providing a power service of
larger magnitude.
[0029] "Charge Control Management" as used herein refers to
enabling or performing the starting, stopping, or level-setting of
a flow of power between a power grid and an electric resource.
[0030] "Power grid operator" as used herein, refers to the entity
that is responsible for maintaining the operation and stability of
the power grid within or across an electric control area. The power
grid operator may constitute some combination of manual/human
action/intervention and automated processes controlling generation
signals in response to system sensors. A "control area operator" is
one example of a power grid operator.
[0031] "Control area" as used herein, refers to a contained portion
of the electrical grid with defined input and output ports. The net
flow of power into this area must equal (within some error
tolerance) the sum of the power consumption within the area and
power outflow from the area.
[0032] "Power grid" as used herein means a power distribution
system/network that connects producers of power with consumers of
power. The network may include generators, transformers,
interconnects, switching stations, and safety equipment as part of
either/both the transmission system (i.e., bulk power) or the
distribution system (i.e. retail power). The power aggregation
system is vertically scalable for use within a neighborhood, a
city, a sector, a control area, or (for example) one of the eight
large-scale Interconnects in the North American Electric
Reliability Council (NERC). Moreover, the system is horizontally
scalable for use in providing power services to multiple grid areas
simultaneously.
[0033] "Grid conditions" as used herein, refers to the need for
more or less power flowing in or out of a section of the electric
power grid, in response to one of a number of conditions, for
example supply changes, demand changes, contingencies and failures,
ramping events, etc. These grid conditions typically manifest
themselves as power quality events such as under- or over-voltage
events or under- or over-frequency events.
[0034] "Power quality events" as used herein typically refers to
manifestations of power grid instability including voltage
deviations and frequency deviations; additionally, power quality
events as used herein also includes other disturbances in the
quality of the power delivered by the power grid such as sub-cycle
voltage spikes and harmonics.
[0035] "Electric resource" as used herein typically refers to
electrical entities that can be commanded to do some or all of
these three things: take power (act as load), provide power (act as
power generation or source), and store energy. Examples may include
battery/charger/inverter systems for electric or hybrid-electric
vehicles, repositories of used-but-serviceable electric vehicle
batteries, fixed energy storage, fuel cell generators, emergency
generators, controllable loads, etc.
[0036] "Electric vehicle" is used broadly herein to refer to pure
electric and hybrid electric vehicles, such as plug-in hybrid
electric vehicles (PHEVs), especially vehicles that have
significant storage battery capacity and that connect to the power
grid for recharging the battery. More specifically, electric
vehicle means a vehicle that gets some or all of its energy for
motion and other purposes from the power grid. Moreover, an
electric vehicle has an energy storage system, which may consist of
batteries, capacitors, etc., or some combination thereof. An
electric vehicle may or may not have the capability to provide
power back to the electric grid.
[0037] Electric vehicle "energy storage systems" (batteries, super
capacitors, and/or other energy storage devices) are used herein as
a representative example of electric resources intermittently or
permanently connected to the grid that can have dynamic input and
output of power. Such batteries can function as a power source or a
power load. A collection of aggregated electric vehicle batteries
can become a statistically stable resource across numerous
batteries, despite recognizable tidal connection trends (e.g., an
increase in the total number of vehicles connected to the grid at
night; a downswing in the collective number of connected batteries
as the morning commute begins, etc.) Across vast numbers of
electric vehicle batteries, connection trends are predictable and
such batteries become a stable and reliable resource to call upon,
should the grid or a part of the grid (such as a person's home in a
blackout) experience a need for increased or decreased power. Data
collection and storage also enable the power aggregation system to
predict connection behavior on a per-user basis.
[0038] An Example of the Presently Disclosed System
[0039] FIG. 1 shows a power aggregation system 100. A flow control
center 102 is communicatively coupled with a network, such as a
public/private mix that includes the Internet 104, and includes one
or more servers 106 providing a centralized power aggregation
service. "Internet" 104 will be used herein as representative of
many different types of communicative networks and network mixtures
(e.g., one or more wide area networks--public or private--and/or
one or more local area networks). Via a network, such as the
Internet 104, the flow control center 102 maintains communication
108 with operators of power grid(s), and communication 110 with
remote resources, i.e., communication with peripheral electric
resources 112 ("end" or "terminal" nodes/devices of a power
network) that are connected to the power grid 114. In one
implementation, power line communicators (PLCs), such as those that
include or consist of Ethernet-over-power line bridges 120 are
implemented at connection locations so that the "last mile" (in
this case, last feet--e.g., in a residence 124) of Internet
communication with remote resources is implemented over the same
wire that connects each electric resource 112 to the power grid
114. Thus, each physical location of each electric resource 112 may
be associated with a corresponding Ethernet-over-power line bridge
120 (hereinafter, "bridge") at or near the same location as the
electric resource 112. Each bridge 120 is typically connected to an
Internet access point of a location owner, as will be described in
greater detail below. The communication medium from flow control
center 102 to the connection location, such as residence 124, can
take many forms, such as cable modem, DSL, satellite, fiber, WiMax,
etc. In a variation, electric resources 112 may connect with the
Internet by a different medium than the same power wire that
connects them to the power grid 114. For example, a given electric
resource 112 may have its own wireless capability to connect
directly with the Internet 104 or an Internet access point and
thereby with the flow control center 102.
[0040] Electric resources 112 of the power aggregation system 100
may include the batteries of electric vehicles connected to the
power grid 114 at residences 124, parking lots 126 etc.; batteries
in a repository 128, fuel cell generators, private dams,
conventional power plants, and other resources that produce
electricity and/or store electricity physically or
electrically.
[0041] In one implementation, each participating electric resource
112 or group of local resources has a corresponding remote
intelligent power flow (IPF) module 134 (hereinafter, "remote IPF
module" 134). The centralized flow control center 102 administers
the power aggregation system 100 by communicating with the remote
IPF modules 134 distributed peripherally among the electric
resources 112. The remote IPF modules 134 perform several different
functions, including, but not limited to, providing the flow
control center 102 with the statuses of remote resources;
controlling the amount, direction, and timing of power being
transferred into or out of a remote electric resource 112;
providing metering of power being transferred into or out of a
remote electric resource 112; providing safety measures during
power transfer and changes of conditions in the power grid 114;
logging activities; and providing self-contained control of power
transfer and safety measures when communication with the flow
control center 102 is interrupted. The remote IPF modules 134 will
be described in greater detail below.
[0042] In another implementation, instead of having an IPF module
134, each electric resource 112 may have a corresponding
transceiver (not shown) to communicate with a local charging
component (not shown). The transceiver and charging component, in
combination, may communicate with flow control center 102 to
perform some or all of the above mentioned functions of IPF module
134. A transceiver and charging component are shown in FIG. 2B and
are described in greater detail herein.
[0043] FIG. 2A shows another view of electrical and communicative
connections to an electric resource 112. In this example, an
electric vehicle 200 includes a battery bank 202 and a remote IPF
module 134. The electric vehicle 200 may connect to a conventional
wall receptacle (wall outlet) 204 of a residence 124, the wall
receptacle 204 representing the peripheral edge of the power grid
114 connected via a residential powerline 206.
[0044] In one implementation, the power cord 208 between the
electric vehicle 200 and the wall outlet 204 can be composed of
only conventional wire and insulation for conducting alternating
current (AC) power to and from the electric vehicle 200. In FIG.
2A, a location-specific connection locality module 210 performs the
function of network access point--in this case, the Internet access
point. A bridge 120 intervenes between the receptacle 204 and the
network access point so that the power cord 208 can also carry
network communications between the electric vehicle 200 and the
receptacle 204. With such a bridge 120 and connection locality
module 210 in place in a connection location, no other special
wiring or physical medium is needed to communicate with the remote
IPF module 134 of the electric vehicle 200 other than a
conventional power cord 208 for providing residential line current
at any conventional voltage. Upstream of the connection locality
module 210, power and communication with the electric vehicle 200
are resolved into the powerline 206 and an Internet cable 104.
[0045] Alternatively, the power cord 208 may include safety
features not found in conventional power and extension cords. For
example, an electrical plug 212 of the power cord 208 may include
electrical and/or mechanical safeguard components to prevent the
remote IPF module 134 from electrifying or exposing the male
conductors of the power cord 208 when the conductors are exposed to
a human user.
[0046] In some embodiments, a radio frequency (RF) bridge (not
shown) may assist the remote IPF module 134 in communicating with a
foreign system, such as a utility smart meter (not shown) and/or a
connection locality module 210. For example, the remote IPF module
134 may be equipped to communicate over power cord 208 or to engage
in some form of RF communication, such as Zigbee or Bluetooth.TM.,
and the foreign system may be able to engage in a different form of
RF communication. In such an implementation, the RF bridge may be
equipped to communicate with both the foreign system and remote IPF
module 134 and to translate communications from one to a form the
other may understand, and to relay those messages. In various
embodiments, the RF bridge may be integrated into the remote IPF
module 134 or foreign system, or may be external to both. The
communicative associations between the RF bridge and remote IPF
module 134 and between the RF bridge and foreign system may be via
wired or wireless communication.
[0047] FIG. 2B shows a further view of electrical and communicative
connections to an electric resource 112. In this example, the
electric vehicle 200 may include a transceiver 212 rather than a
remote IPF module 134. The transceiver 212 may be communicatively
coupled to a charging component 214 through a connection 216, and
the charging component itself may be coupled to a conventional wall
receptacle (wall outlet) 204 of a residence 124 and to electric
vehicle 200 through a power cord 208. The other components shown in
FIG. 2B may have the couplings and functions discussed with regard
to FIG. 2A.
[0048] In various embodiments, transceiver 212 and charging
component 214 may, in combination, perform the same functions as
the remote IPF module 134. Transceiver 212 may interface with
computer systems of electric vehicle 200 and communicate with
charging component 214, providing charging component 214 with
information about electric vehicle 200, such as its vehicle
identifier, a location identifier, and a state of charge. In
response, transceiver 212 may receive requests and commands which
transceiver 212 may relay to vehicle 200's computer systems.
[0049] Charging component 214, being coupled to both electric
vehicle 200 and wall outlet 204, may effectuate charge control of
the electric vehicle 200. If the electric vehicle 200 is not
capable of charge control management, charging component 214 may
directly manage the charging of electric vehicle 200 by stopping
and starting a flow of power between the electric vehicle 200 and a
power grid 114 in response to commands received from a flow control
server 106. If, on the other hand, the electric vehicle 200 is
capable of charge control management, charging component 214 may
effectuate charge control by sending commands to the electric
vehicle 200 through the transceiver 212.
[0050] In some embodiments, the transceiver 212 may be physically
coupled to the electric vehicle 200 through a data port, such as an
OBD-II connector. In other embodiments, other couplings may be
used. The connection 216 between transceiver 212 and charging
component 214 may be a wireless signal, such as a radio frequency
(RF), such as a Zigbee, or Bluetooth.TM. signal. And charging
component 214 may include a receiver socket to couple with power
cord 208 and a plug to couple with wall outlet 204. In one
embodiment, charging component 214 may be coupled to connection
locality module 210 in either a wired or wireless fashion. For
example, charging component 214 may have a data interface for
communicating wirelessly with both the transceiver 212 and locality
module 210. In such an embodiment, the bridge 120 may not be
required.
[0051] Further details about the transceiver 212 and charging
component 214 are illustrated by FIG. 8B and described in greater
detail herein.
[0052] FIG. 3 shows another implementation of the connection
locality module 210 of FIG. 2, in greater detail. In FIG. 3, an
electric resource 112 has an associated remote IPF module 134,
including a bridge 120. The power cord 208 connects the electric
resource 112 to the power grid 114 and also to the connection
locality module 210 in order to communicate with the flow control
server 106.
[0053] The connection locality module 210 includes another instance
of a bridge 120, connected to a network access point 302, which may
include such components as a router, switch, and/or modem, to
establish a hardwired or wireless connection with, in this case,
the Internet 104. In one implementation, the power cord 208 between
the two bridges 120 and 120' is replaced by a wireless Internet
link, such as a wireless transceiver in the remote IPF module 134
and a wireless router in the connection locality module 210.
[0054] In other embodiments, a transceiver 212 and charging
component 214 may be used instead of a remote IPF module 134. In
such an embodiment, the charging component 214 may include or be
coupled to a bridge 120, and the connection locality module 210 may
also include a bridge 120', as shown. In yet other embodiments, not
shown, charging component 214 and connection locality module 210
may communicate in a wired or wireless fashion, as mentioned
previously, without bridges 120 and 120'. The wired or wireless
communication may utilize any sort of connection technology known
in the art, such as Ethernet or RF communication, such as Zigbee,
or Bluetooth.
[0055] System Layouts
[0056] FIG. 4 shows a layout 400 of the power aggregation system
100. The flow control center 102 can be connected to many different
entities, e.g., via the Internet 104, for communicating and
receiving information. The layout 400 includes electric resources
112, such as plug-in electric vehicles 200, physically connected to
the grid within a single control area 402. The electric resources
112 become an energy resource for grid operators 404 to
utilize.
[0057] The layout 400 also includes end users 406 classified into
electric resource owners 408 and electrical connection location
owners 410, who may or may not be one and the same. In fact, the
stakeholders in a power aggregation system 100 include the system
operator at the flow control center 102, the grid operator 404, the
resource owner 408, and the owner of the location 410 at which the
electric resource 112 is connected to the power grid 114.
[0058] Electrical connection location owners 410 can include:
[0059] Rental car lots--rental car companies often have a large
portion of their fleet parked in the lot. They can purchase fleets
of electric vehicles 200 and, participating in a power aggregation
system 100, generate revenue from idle fleet vehicles.
[0060] Public parking lots--parking lot owners can participate in
the power aggregation system 100 to generate revenue from parked
electric vehicles 200. Vehicle owners can be offered free parking,
or additional incentives, in exchange for providing power
services.
[0061] Workplace parking--employers can participate in a power
aggregation system 100 to generate revenue from parked employee
electric vehicles 200. Employees can be offered incentives in
exchange for providing power services.
[0062] Residences--a home garage can merely be equipped with a
connection locality module 210 to enable the homeowner to
participate in the power aggregation system 100 and generate
revenue from a parked car. Also, the vehicle battery 202 and
associated power electronics within the vehicle can provide local
power backup power during times of peak load or power outages.
[0063] Residential neighborhoods--neighborhoods can participate in
a power aggregation system 100 and be equipped with power-delivery
devices (deployed, for example, by homeowner cooperative groups)
that generate revenue from parked electric vehicles 200.
[0064] The grid operations 116 of FIG. 4 collectively include
interactions with energy markets 412, the interactions of grid
operators 404, and the interactions of automated grid controllers
118 that perform automatic physical control of the power grid
114.
[0065] The flow control center 102 may also be coupled with
information sources 414 for input of weather reports, events, price
feeds, etc. Other data sources 414 include the system stakeholders,
public databases, and historical system data, which may be used to
optimize system performance and to satisfy constraints on the power
aggregation system 100.
[0066] Thus, a power aggregation system 100 may consist of
components that:
[0067] communicate with the electric resources 112 to gather data
and actuate charging/discharging of the electric resources 112;
[0068] gather real-time energy prices;
[0069] gather real-time resource statistics;
[0070] predict behavior of electric resources 112 (connectedness,
location, state (such as battery State-Of-Charge) at a given time
of interest, such as a time of connect/disconnect);
[0071] predict behavior of the power grid 114/load;
[0072] encrypt communications for privacy and data security;
[0073] actuate charging of electric vehicles 200 to optimize some
figure(s) of merit;
[0074] offer guidelines or guarantees about load availability for
various points in the future, etc.
[0075] These components can be running on a single computing
resource (computer, etc.), or on a distributed set of resources
(either physically co-located or not).
[0076] Power aggregation systems 100 in such a layout 400 can
provide many benefits: for example, lower-cost ancillary services
(i.e., power services), fine-grained (both temporal and spatial)
control over resource scheduling, guaranteed reliability and
service levels, increased service levels via intelligent resource
scheduling, and/or firming of intermittent generation sources such
as wind and solar power generation.
[0077] The power aggregation system 100 enables a grid operator 404
to control the aggregated electric resources 112 connected to the
power grid 114. An electric resource 112 can act as a power source,
load, or storage, and the resource 112 may exhibit combinations of
these properties. Control of a set of electric resources 112 is the
ability to actuate power consumption, generation, or energy storage
from an aggregate of these electric resources 112.
[0078] FIG. 5 shows the role of multiple control areas 402 in the
power aggregation system 100. Each electric resource 112 can be
connected to the power aggregation system 100 within a specific
electrical control area. A single instance of the flow control
center 102 can administer electric resources 112 from multiple
distinct control areas 501 (e.g., control areas 502, 504, and 506).
In one implementation, this functionality is achieved by logically
partitioning resources within the power aggregation system 100. For
example, when the control areas 402 include an arbitrary number of
control areas, control area "A" 502, control area "B" 504, . . . ,
control area "n" 506, then grid operations 116 can include
corresponding control area operators 508, 510, . . . , and 512.
Further division into a control hierarchy that includes control
division groupings above and below the illustrated control areas
402 allows the power aggregation system 100 to scale to power grids
114 of different magnitudes and/or to varying numbers of electric
resources 112 connected with a power grid 114.
[0079] FIG. 6 shows a layout 600 of a power aggregation system 100
that uses multiple centralized flow control centers 102 and 102'
and a directory server 602 for determining a flow control center.
Each flow control center 102 and 102' has its own respective end
users 406 and 406'. Control areas 402 to be administered by each
specific instance of a flow control center 102 can be assigned
dynamically. For example, a first flow control center 102 may
administer control area A 502 and control area B 504, while a
second flow control center 102' administers control area n 506.
Likewise, corresponding control area operators (508, 510, and 512)
are served by the same flow control center 102 that serves their
respective different control areas.
[0080] In various embodiments, an electric resource may determine
which flow control center 102/102' administers its control area
502/504/506 by communicating with a directory server 602. The
address of the directory server 602 may be known to electric
resource 112 or its associated IPF module 134 or charging component
214. Upon plugging in, the electric resource 112 may communicate
with the directory server 602, providing the directory server 112
with a resource identifier and/or a location identifier. Based on
this information, the directory server 602 may respond, identifying
which flow control center 102/102' to use.
[0081] In another embodiment, directory server 602 may be
integrated with a flow control server 106 of a flow control center
102/102'. In such an embodiment, the electric resource 112 may
contact the server 106. In response, the server 106 may either
interact with the electric resource 112 itself or forward the
connection to another flow control center 102/102' responsible for
the location identifier provided by the electric resource 112.
[0082] In some embodiments, whether integrated with a flow control
server 106 or not, directory server 602 may include a publicly
accessible database for mapping locations to flow control centers
102/102'.
[0083] Flow Control Server
[0084] FIG. 7 shows a server 106 of the flow control center 102.
The illustrated implementation in FIG. 7 is only one example
configuration, for descriptive purposes. Many other arrangements of
the illustrated components or even different components
constituting a server 106 of the flow control center 102 are
possible within the scope of the subject matter. Such a server 106
and flow control center 102 can be executed in hardware, software,
or combinations of hardware, software, firmware, etc.
[0085] The flow control server 106 includes a connection manager
702 to communicate with electric resources 112, a prediction engine
704 that may include a learning engine 706 and a statistics engine
708, a constraint optimizer 710, and a grid interaction manager 712
to receive grid control signals 714. Grid control signals 714 are
sometimes referred to as generation control signals, such as
automated generation control (AGC) signals. The flow control server
106 may further include a database/information warehouse 716, a web
server 718 to present a user interface to electric resource owners
408, grid operators 404, and electrical connection location owners
410; a contract manager 720 to negotiate contract terms with energy
markets 412, and an information acquisition engine 414 to track
weather, relevant news events, etc., and download information from
public and private databases 722 for predicting behavior of large
groups of the electric resources 112, monitoring energy prices,
negotiating contracts, etc.
[0086] Remote IPF Module
[0087] FIG. 8A shows the remote IPF module 134 of FIGS. 1 and 2 in
greater detail. The illustrated remote IPF module 134 is only one
example configuration, for descriptive purposes. Many other
arrangements of the illustrated components or even different
components constituting a remote IPF module 134 are possible within
the scope of the subject matter. Such a remote IPF module 134 has
some hardware components and some components that can be executed
in hardware, software, or combinations of hardware, software,
firmware, etc. In other embodiments, executable instructions
configured to perform some or all of the operations of remote IPF
module 134 may be added to hardware of an electric resource 112
such as an electric vehicle that, when combined with the executable
instructions, provides equivalent functionality to remote IPF
module 134. References to remote IPF module 134 as used herein
include such executable instructions.
[0088] The illustrated example of a remote IPF module 134 is
represented by an implementation suited for an electric vehicle
200. Thus, some vehicle systems 800 are included as part of the
remote IPF module 134 for the sake of description. However, in
other implementations, the remote IPF module 134 may exclude some
or all of the vehicles systems 800 from being counted as components
of the remote IPF module 134.
[0089] The depicted vehicle systems 800 include a vehicle computer
and data interface 802, an energy storage system, such as a battery
bank 202, and an inverter/charger 804. Besides vehicle systems 800,
the remote IPF module 134 also includes a communicative power flow
controller 806. The communicative power flow controller 806 in turn
includes some components that interface with AC power from the grid
114, such as a powerline communicator, for example an
Ethernet-over-powerline bridge 120, and a current or
current/voltage (power) sensor 808, such as a current sensing
transformer.
[0090] The communicative power flow controller 806 also includes
Ethernet and information processing components, such as a processor
810 or microcontroller and an associated Ethernet media access
control (MAC) address 812; volatile random access memory 814,
nonvolatile memory 816 or data storage, an interface such as an
RS-232 interface 818 or a CAN-bus interface 820; an Ethernet
physical layer interface 822, which enables wiring and signaling
according to Ethernet standards for the physical layer through
means of network access at the MAC/Data Link Layer and a common
addressing format. The Ethernet physical layer interface 822
provides electrical, mechanical, and procedural interface to the
transmission medium--i.e., in one implementation, using the
Ethernet-over-powerline bridge 120. In a variation, wireless or
other communication channels with the Internet 104 are used in
place of the Ethernet-over-powerline bridge 120.
[0091] The communicative power flow controller 806 also includes a
bidirectional power flow meter 824 that tracks power transfer to
and from each electric resource 112, in this case the battery bank
202 of an electric vehicle 200.
[0092] The communicative power flow controller 806 operates either
within, or connected to an electric vehicle 200 or other electric
resource 112 to enable the aggregation of electric resources 112
introduced above (e.g., via a wired or wireless communication
interface). These above-listed components may vary among different
implementations of the communicative power flow controller 806, but
implementations typically include:
[0093] an intra-vehicle communications mechanism that enables
communication with other vehicle components;
[0094] a mechanism to communicate with the flow control center
102;
[0095] a processing element;
[0096] a data storage element;
[0097] a power meter; and
[0098] optionally, a user interface.
[0099] Implementations of the communicative power flow controller
806 can enable functionality including:
[0100] executing pre-programmed or learned behaviors when the
electric resource 112 is offline (not connected to Internet 104, or
service is unavailable);
[0101] storing locally-cached behavior profiles for "roaming"
connectivity (what to do when charging on a foreign system, i.e.,
when charging in the same utility territory on a foreign meter or
in a separate utility territory, or in disconnected operation,
i.e., when there is no network connectivity);
[0102] allowing the user to override current system behavior;
and
[0103] metering power-flow information and caching meter data
during offline operation for later transaction.
[0104] Thus, the communicative power flow controller 806 includes a
central processor 810, interfaces 818 and 820 for communication
within the electric vehicle 200, a powerline communicator, such as
an Ethernet-over-powerline bridge 120 for communication external to
the electric vehicle 200, and a power flow meter 824 for measuring
energy flow to and from the electric vehicle 200 via a connected AC
powerline 208.
[0105] Power Flow Meter
[0106] Power is the rate of energy consumption per interval of
time. Power indicates the quantity of energy transferred during a
certain period of time, thus the units of power are quantities of
energy per unit of time. The power flow meter 824 measures power
for a given electric resource 112 across a bidirectional
flow--e.g., power from grid 114 to electric vehicle 200 or from
electric vehicle 200 to the grid 114. In one implementation, the
remote IPF module 134 can locally cache readings from the power
flow meter 824 to ensure accurate transactions with the central
flow control server 106, even if the connection to the server is
down temporarily, or if the server itself is unavailable.
[0107] Transceiver and Charging Component
[0108] FIG. 8B shows the transceiver 212 and charging component 214
of FIG. 2B in greater detail. The illustrated transceiver 212 and
charging component 214 is only one example configuration, for
descriptive purposes. Many other arrangements of the illustrated
components or even different components constituting the
transceiver 212 and charging component 214 are possible within the
scope of the subject matter. Such a transceiver 212 and charging
component 214 have some hardware components and some components
that can be executed in hardware, software, or combinations of
hardware, software, firmware, etc.
[0109] The illustrated example of the transceiver 212 and charging
component 214 is represented by an implementation suited for an
electric vehicle 200. Thus, some vehicle systems 800 are
illustrated to provide context to the transceiver 212 and charging
component 214 components.
[0110] The depicted vehicle systems 800 include a vehicle computer
and data interface 802, an energy storage system, such as a battery
bank 202, and an inverter/charger 804. In some embodiments, vehicle
systems 800 may include a data port, such as an OBD-II port, that
is capable of physically coupling with the transceiver 212. The
transceiver 212 may then communicate with the vehicle computer and
data interface 802 through the data port, receiving information
from electric resource 112 comprised by vehicle systems 800 and, in
some embodiments, providing commands to the vehicle computer and
data interface 802. In one implementation, the vehicle computer and
data interface 802 may be capable of charge control management. In
such an embodiment, the vehicle computer and data interface 802 may
perform some or all of the charging component 214 operations
discussed below. In other embodiments, executable instructions
configured to perform some or all of the operations of the vehicle
computer and data interface 802 may be added to hardware of an
electric resource 112 such as an electric vehicle that, when
combined with the executable instructions, provides equivalent
functionality to the vehicle computer and data interface 802.
References to the vehicle computer and data interface 802 as used
herein include such executable instructions.
[0111] In various embodiments, the transceiver 212 may have a
physical form that is capable of coupling to a data port of vehicle
systems 800. Such a transceiver 212 may also include a plurality of
interfaces, such as an RS-232 interface 818 and/or a CAN-bus
interface 820. In various embodiments, the RS-232 interface 818 or
CAN-bus interface 820 may enable the transceiver 212 to communicate
with the vehicle computer and data interface 802 through the data
port. Also, the transceiver may be or comprise an additional
interface (not shown) capable of engaging in wireless communication
with a data interface 820 of the charging component 214. The
wireless communication may be of any form known in the art, such as
radio frequency (RF) communication (e.g., Zigbee, and/or
Bluetooth.TM. communication). In other embodiments, the transceiver
may comprise a separate conductor or may be configured to utilize a
powerline 208 to communicate with charging component 214. In yet
other embodiments, not shown, transceiver 212 may simply be a radio
frequency identification (RFID) tag capable of storing minimal
information about the electric resource 112, such as a resource
identifier, and of being read by a corresponding RFID reader of
charging component 214. In such other embodiments, the RFID tag may
not couple with a data port or communicate with the vehicle
computer and data interface 802.
[0112] As shown, the charging component 214 may be an intelligent
plug device that is physically connected to a charging medium, such
as a powerline 208 (the charging medium coupling the charging
component 214 to the electric resource 112) and an outlet of a
power grid (such as the wall outlet 204 shown in FIG. 2B). In other
embodiments charging component 214 may be a charging station or
some other external control. In some embodiments, the charging
component 214 may be portable.
[0113] In various embodiments, the charging component 214 may
include components that interface with AC power from the grid 114,
such as a powerline communicator, for example an
Ethernet-over-powerline bridge 120, and a current or
current/voltage (power) sensor 808, such as a current sensing
transformer.
[0114] In other embodiments, the charging component 214 may include
a further Ethernet plug or wireless interface in place of bridge
120. In such an embodiment, data-over-powerline communication is
not necessary, eliminating the need for a bridge 120. The Ethernet
plug or wireless interface may communicate with a local access
point, and through that access point to flow control server
106.
[0115] The charging component 214 may also include Ethernet and
information processing components, such as a processor 810 or
microcontroller and an associated Ethernet media access control
(MAC) address 812; volatile random access memory 814, nonvolatile
memory 816 or data storage, a data interface 826 for communicating
with the transceiver 212, and an Ethernet physical layer interface
822, which enables wiring and signaling according to Ethernet
standards for the physical layer through means of network access at
the MAC/Data Link Layer and a common addressing format. The
Ethernet physical layer interface 822 provides electrical,
mechanical, and procedural interface to the transmission
medium--i.e., in one implementation, using the
Ethernet-over-powerline bridge 120. In a variation, wireless or
other communication channels with the Internet 104 are used in
place of the Ethernet-over-powerline bridge 120.
[0116] The charging component 214 may also include a bidirectional
power flow meter 824 that tracks power transfer to and from each
electric resource 112, in this case the battery bank 202 of an
electric vehicle 200.
[0117] Further, in some embodiments, the charging component 214 may
comprise an RFID reader to read the electric resource information
from transceiver 212 when transceiver 212 is an RFID tag.
[0118] Also, in various embodiments, the charging component 214 may
include a credit card reader to enable a user to identify the
electric resource 112 by providing credit card information. In such
an embodiment, a transceiver 212 may not be necessary.
[0119] Additionally, in one embodiment, the charging component 214
may include a user interface, such as one of the user interfaces
described in greater detail below.
[0120] Implementations of the charging component 214 can enable
functionality including:
[0121] executing pre-programmed or learned behaviors when the
electric resource 112 is offline (not connected to Internet 104, or
service is unavailable);
[0122] storing locally-cached behavior profiles for "roaming"
connectivity (what to do when charging on a foreign system or in
disconnected operation, i.e., when there is no network
connectivity);
[0123] allowing the user to override current system behavior;
and
[0124] metering power-flow information and caching meter data
during offline operation for later transaction.
[0125] User Interfaces (UI)
[0126] Charging Station UI. An electrical charging station, whether
free or for pay, can be installed with a user interface that
presents useful information to the user. Specifically, by
collecting information about the grid 114, the electric resource
state, and the preferences of the user, the station can present
information such as the current electricity price, the estimated
recharge cost, the estimated time until recharge, the estimated
payment for uploading power to the grid 114 (either total or per
hour), etc. The information acquisition engine 414 communicates
with the electric resource 112 and with public and/or private data
networks 722 to acquire the data used in calculating this
information.
[0127] The types of information gathered from the electric resource
112 can include an electric resource identifier (resource ID) and
state information like the state of charge of the electric resource
112. The resource ID can be used to obtain knowledge of the
electric resource type and capabilities, preferences, etc. through
lookup with the flow control server 106.
[0128] In various embodiments, the charging station system
including the UI may also gather grid-based information, such as
current and future energy costs at the charging station.
[0129] User Charge Control UI Mechanisms. In various embodiments,
by default, electric resources 112 may receive charge control
management via power aggregation system 100. In some embodiments,
an override control may be provided to override charge control
management and charge as soon as possible. The override control may
be provided, in various embodiments, as a user interface mechanism
of the remote IPF module 134, the charging component 214, of the
electric resource (for example, if electric resource is a vehicle
200, the user interface control may be integrated with dash
controls of the vehicle 200) or even via a web page offered by flow
control server 106. The control can be presented, for example, as a
button, a touch screen option, a web page, or some other UI
mechanism. In one embodiment, the UI may be the UI illustrated by
FIG. 8C and discussed in greater detail below. In some embodiments,
the override is a one-time override, only applying to a single
plug-in session. Upon disconnecting and reconnecting, the user may
again need to interact with the UI mechanism to override the charge
control management.
[0130] In some embodiments, the user may pay more to charge with
the override on than under charge control management, thus
providing an incentive for the user to accept charge control
management. Such a cost differential may be displayed or rendered
to the user in conjunction with or on the UI mechanism. This
differential can take into account time-varying pricing, such as
Time of Use (TOU), Critical Peak Pricing (CPP), and Real-Time
Pricing (RTP) schemes, as discussed above, as well as any other
incentives, discounts, or payments that may be forgone by not
accepting charge control management.
[0131] UI Mechanism for Management Preferences. In various
embodiments, a user interface mechanism of the remote IPF module
134, the charging component 214, of the electric resource (for
example, if electric resource is a vehicle 200, the user interface
control may be integrated with dash controls of the vehicle 200) or
even via a web page offered by flow control server 106 may enable a
user to enter and/or edit management preferences to affect charge
control management of the user's electric resource 112. In some
embodiments, the UI mechanism may allow the user to enter/edit
general preferences, such as whether charge control management is
enabled, whether vehicle-to-grid power flow is enabled or whether
the electric resource 112 should only be charged with clean/green
power. Also, in various embodiments, the UI mechanism may enable a
user to prioritize relative desires for minimizing costs,
maximizing payments (i.e., fewer charge periods for higher
amounts), achieving a full state-of-charge for the electric
resource 112, charging as rapidly as possible, and/or charging in
as environmentally-friendly a way as possible. Additionally, the UI
mechanism may enable a user to provide a default schedule for when
the electric resource will be used (for example, if resource 112 is
a vehicle 200, the schedule is for when the vehicle 200 should be
ready to drive). Further, the UI mechanism may enable the user to
add or select special rules, such as a rule not to charge if a
price threshold is exceeded or a rule to only use charge control
management if it will earn the user at least a specified threshold
of output. Charge control management may then be effectuated based
on any part or all of these user entered preferences.
[0132] Simple User Interface. FIG. 8C illustrates a simple user
interface (UI) which enables a user to control charging based on
selecting among a limited number of high level preferences. For
example, UI 2300 includes the categories "green", "fast", and
"cheap" (with what is considered "green", "fast", and "cheap"
varying from embodiment to embodiment). The categories shown in UI
2300 are selected only for the sake of illustration and may instead
includes these and/or any other categories applicable to electric
resource 112 charging known in the art. As shown, the UI 2300 may
be very basic, using well known form controls such as radio
buttons. In other embodiments, other graphic controls known in the
art may be used. The general categories may be mapped to specific
charging behaviors, such as those discussed above, by a flow
control server 106.
[0133] Electric Resource Communication Protocol
[0134] FIG. 9 illustrates a resource communication protocol. As
shown, a remote IPF module 134 or charging component 214 may be in
communication with a flow control server 106 over the Internet 104
or another networking fabric or combination of networking fabrics.
In various embodiments, a protocol specifying an order of messages
and/or a format for messages may be used to govern the
communications between the remote IPF module 134 or charging
component 214 and flow control server 106.
[0135] In some embodiments, the protocol may include two channels,
one for messages initiated by the remote IPF module 134 or charging
component 214 and for replies to those messages from the flow
control server 106, and another channel for messages initiated by
the flow control server 106 and for replies to those messages from
the remote IPF module 134 or charging component 214. The channels
may be asynchronous with respect to each other (that is, initiation
of messages on one channel may be entirely independent of
initiation of messages on the other channel). However, each channel
may itself be synchronous (that is, once a message is sent on a
channel, another message may not be sent until a reply to the first
message is received).
[0136] As shown, the remote IPF module 134 or charging component
214 may initiate communication 902 with the flow control server
106. In some embodiments, communication 902 may be initiated when,
for example, an electric resource 112 first plugs in/connects to
the power grid 114. In other embodiments, communication 902 may be
initiated at another time or times. The initial message 902
governed by the protocol may require, for example, one or more of
an electric resource identifier, such as a MAC address, a protocol
version used, and/or a resource identifier type.
[0137] Upon receipt of the initial message by the flow control
server 106, a connection may be established between the remote IPF
module 134 or charging component 214 and flow control server 106.
Upon establishing a connection, the remote IPF module 134 or
charging component 214 may register with flow control server 106
through a subsequent communication 903. Communication 903 may
include a location identifier scheme, a latitude, a longitude, a
max power value that the remote IPF module 134 or charging
component 214 can draw, a max power value that the remote IPF
module 134 or charging component 214 can provide, a current power
value, and/or a current state of charge.
[0138] After the initial message 902, the protocol may require or
allow messages 904 from the flow control server 106 to the remote
IPF module 134 or charging component 214 or messages 906 from
remote IPF module 134 or charging component 214 to the flow control
server 106. The messages 904 may include, for example, one or more
of commands, messages, and/or updates. Such messages 904 may be
provided at any time after the initial message 902. In one
embodiment, messages 904 may include a command setting, a power
level and/or a ping to determine whether the remote IPF module 134
or charging component 214 is still connected.
[0139] The messages 906 may include, for example, status updates to
the information provided in the registration message 903. Such
messages 906 may be provided at any time after the initial message
902. In one embodiment, the messages 906 may be provided on a
pre-determined time interval basis. In various embodiments,
messages 906 may even be sent when the remote IPF module 134 or
charging component 214 is connected, but not registered. Such
messages 906 may include data that is stored by flow control server
106 for later processing. Also, in some embodiments, messages 904
may be provided in response to a message 902 or 906.
[0140] Bandwidth Minimization Techniques
[0141] A distributed energy management system must be in constant
communication with the distributed energy resources to maintain a
high level of certainty that the system is behaving as reported.
Sending messages between the energy management system and the
distributed energy resources is expensive because each message has
a cost associated with it. Minimizing the number of bytes sent
between the system and the resources will minimize the
communications cost of the system. Accordingly, the consumption of
network bandwidth is reduced.
[0142] Bandwidth, as used herein, can refer to network bandwidth.
Bandwidth is the number of bytes per second of data traffic that
flows into or out of a device or control system. Devices managed by
the power flow management system can be any load, generation, or
storage asset. Storage assets can comprise batteries and
bi-directional power electronics such as inverters and chargers.
Load assets may include water heaters, plug-in electric or plug-in
hybrid electric vehicles, water heaters, generation facilities, or
other controllable load, storage, or generation asset.
[0143] The disclosed system and methods can provide for the
minimization of network traffic consumption in a system that
manages the power flows to and from devices connected to a power
grid. This power flow management system communicates with the
devices, and can be centralized or decentralized. Through this
communication, information about power flows is communicated to
devices and information about device behavior and status is
communicated to the system.
[0144] The system communicates with the devices to instruct devices
as to when and at what rate energy should be taken from and
delivered to the grid. These commands enable the devices to consume
or produce energy when doing so is deemed optimal by the power flow
management system.
[0145] The instructions that are delivered to the devices by the
power flow management system can take many forms. One form of
instruction is a direct command to flow power immediately at the
requested level. Another form of instruction is a schedule of power
flow that should be followed by the device and can take many forms.
A schedule can indicate a single point in time at which a power
flow level should be activated. A schedule can indicate a sequence
of power flow levels that should be activated at various times in
the future. The schedule can be repeating on a dynamic or fixed
pattern, e.g. repeat a set of actions each day, each week, etc.
[0146] The devices also communicate information to the power flow
management system about the current state of the world at the
device. Information that can be transmitted for the benefit of
controlling power flows includes information about how much power
is currently flowing through the device and in what direction,
capacity information pertaining to the resource (e.g. storage state
of charge, fuel level of a generator), faults and error messages,
presence of a resource (e.g.: electric vehicles come and go; is the
electric vehicle currently available), scheduling constraints (e.g.
how long is the resource available), energy consumption in a period
(e.g. kWh consumed/produced in the last time period), etc.
[0147] Sending messages between the power flow management system
and the devices requires the sending of data bytes across a
network, which consumes network bandwidth. Because many
communications costs can be directly measured by the number of
bytes transferred to and from a device, minimizing the transfer of
bytes between the device and the power flow management system
minimizes the communications costs and consumption of network
bandwidth.
[0148] A power flow management system can perform in a more
efficient manner when it has complete information about the state
of all of the devices under its control at all times. To realize
this level of information awareness requires all assets to
communication all information pertaining to the power flow
management system in a timely fashion. Such a level of information
communication comes with an associated cost.
[0149] There are a number of techniques that can be used to reduce
the network traffic consumption in a power flow management system
to reduce the cost of communicating with the distributed assets.
Such techniques include the following: data compression, data
overhead reduction, action/schedule pre-distribution, minimum
change dispatch, communication of all status changes, configuration
limits on relevant behavior, and non-time-critical information
bundling. These bandwidth minimization techniques, and embodiments
thereof, are further described below.
[0150] Data Compression. One of the techniques for minimizing bytes
between the system and the distributed resources is data
compression within a message. Compressing the data that is sent
between the power flow management system and the distributed
devices can reduce the total network traffic consumption.
[0151] A power flow management system that communicates with
devices can send compressed messages to save on network traffic.
One manner in which this works is to have both the power flow
management server and the device use a compression algorithm or
library (such as zlib or gzip) to compress data before transmission
and to decompress data after transmission.
[0152] Reducing Data Overhead. In one technique, more bytes are
included into a single message in order to reduce per-message
overhead. Because each network message has some associated
overhead, it is beneficial to put more data into a single message
to reduce the network consumption on overhead traffic.
[0153] A device that is part of a power flow management system may
collect data from its sensors and internal processes. For the bits
of data that are not time critical to the system, the device can
cache the data until the ratio of data to overhead is less than 5%.
In the case of TCP/IP, this means waiting until the device had
gathered 1280 bytes of data before sending.
[0154] Action and Schedule Pre-distribution. For complicated or
long sequences of actions, these actions can be pre-distributed to
the devices (or distributed one time over the network). When any of
the pre-distributed actions need to be communicated, an identifier
for the more complicated sequence is all that needs to be
communicated. For dispatching actions or sets of actions,
pre-compute large sets of actions can be directed using an action
identifier. As such, the action sets are coded and only the code is
transmitted. While this method consumes memory on the client and
server, bandwidth consumption is reduced.
[0155] To achieve an application-level data compression, a power
flow management system can define a set of compact messages that
represent a pre-defined set of functionality. For example, consider
a device that runs just 4 distinct schedules during its normal
behavior. Rather than send the schedule that the device should run
each time the behavior should begin, the power flow management
system can send the device each schedule just once. Subsequent
times that each of those four schedules need to run, the power flow
management system can indicate which of the four schedules to run
(by name or ID), and a substantial amount of bandwidth can be
saved.
[0156] Minimum Change Dispatch. Another technique for minimizing
bytes between the system and the distributed resources includes
dispatching resources in a way that minimizes the total state
change on a per-resource basis within the system. In one example,
as few resources as possible communicate in order to effect the
desired change within the system. Each time that the power flow
management system needs to change the state of the distributed
devices (e.g. now there is a need for 15 MW of power flow in some
part of the grid, where the earlier needs was for only 13 MW), it
can choose to achieve the targeted power flow by looking for the
minimum number of changes in the system (e.g. a device that was off
needs to be on or vice versa) that satisfies the constraint. In one
embodiment, techniques use a single bit to toggle from one state to
another, such as from off to on and from on to off.
[0157] There are many different algorithms that a power flow
management system can use to determine which of the connected
devices should be at what power flow level at any point in time.
Should the power flow management system need to revise the net
aggregate behavior of the power flow management system, it will
likely need to communicate with some subset of the connected
resources to signal a change in behavior.
[0158] One measure of the quality of a particular set of device
change orders is how many of the resources need to be contacted to
enact the change. One algorithm for achieving the minimum change
set to achieve the system-wide power flow goal is to find resource
for which a power flow change in the required direction is
possible, and to then sort the devices by the amount of power flow
they control. Starting with the device that controls the most
power, work down the list of available devices until enough power
has been recruited to achieve the goal of the power flow
system.
[0159] Devices should communicate all status changes. This
technique does not use application level pings. In the case of any
change in device status (e.g. power level change, fuel level change
by some interesting quantity, resource arrived/departed where
resource may be a vehicles), communicating all such status changes
eliminates the need for the power flow management system to use
application level pings (i.e. messages from the power flow
management system, which has the purpose of asking the device "Are
you there?").
[0160] In one embodiment, the implemented technique provides that
resources communicate their departure from the system. This enables
the removal of all application level pings from the system. This
also requires that the resources have the ability to maintain power
for enough time after being disconnected that they can communicate.
When there is a local communications controller, the controller can
indicate the disappearance of a resource to the system.
[0161] Configurable limits on interesting behavior. Another
bandwidth minimization technique involves increasing the tolerance
limits for state changes that require notification of the main
system. Relevant information should be communicated to the power
flow management system in real time. The devices should support the
ability to increase and decrease the limits of interesting behavior
to make the network traffic consumption be tailor-able against
responsiveness (e.g. knowing each time the power flow changes by 3%
is more informative than if it changes by 10% but requires network
bandwidth to communicate).
[0162] Non-time-critical information should be bundled. Techniques
may minimize message overhead by saving data that is not
time-sensitive for same-message transmission with data that is time
sensitive, thereby saving the messaging overhead and enabling data
compression on a larger message. For information that is not time
critical to the operation of the power flow information system
(diagnostic data, logged data, summary statistics, etc), the
devices should gather this information in memory and only transmit
it to the power flow management system when a sufficient amount of
information is collected such that the portion of the message
dedicated to overhead is small.
[0163] Various combination of the bandwidth minimization techniques
may be implemented in an embodiment. For example, devices may
communicate all interesting changes to the power flow management
system and the limits defining interesting behavior for the device
may be configurable. A power flow system that is fully informed and
frequently updated about the behavior of the endpoints that are
connected to it defines one endpoint on a continuum of control and
flexibility. On the other end of the spectrum is a power flow
management system that has little or no visibility into the
behavior and status of the devices connected to it.
[0164] To enable the most flexible power flow management system
while minimizing the use of network traffic, the system can
establish criteria for devices that triggers an update action of
status to the power flow management system. This way, only when
something changes in the status of the device does communication
need to be made. Such a scheme does not waste network traffic
having devices inform the power flow management system that things
are unchanged from the last communication.
[0165] For example, consider a battery charging device that is
connected to a battery and participates in the network of the power
flow management system. Once the device has connected to the power
flow management system and reported its power flow (e.g. 800 W),
there is no need for the device to report new information to the
power flow management system unless there is a change in status.
For example, if a device is reporting the amount of power flowing
into a battery that is being charged and the battery fills up and
does not require further charging.
[0166] FIG. 10 illustrates an embodiment of a bandwidth
minimization technique. A power flow management system, which
manages electric devices and electric power supplies 1010,
communicates device information 1020 and power flow information
1030. Bandwidth reduction techniques described above are applied to
reduce network traffic 1040.
[0167] Smart Energy Protocol Translation Device
[0168] A protocol translation device may be provided that fully
participates in two or more networks using physical signaling
mechanisms that are capable of communication with each network.
Messages are reformulated messages such that the messages can pass
from one network to another. Since two relevant protocols may not
be compatible, such a device passes high-level information as
opposed to binary packets. This method is distinct from the method
used by Internet routers that simply forward messages from one
network to another without modification.
[0169] A Power Line Communicator (PLC), such as a power line
carrier, is a signaling mechanism by which a high-frequency signal
is added to the AC power line in a home or business. The
high-frequency signal carries information in a variety of protocols
to other devices that are able to decode these high frequency
signals.
[0170] The protocol translation device may include the following: a
microprocessor and power supply; physical transceivers for each
supported communications protocol stack; a software stack capable
of decoding messages from each of the communications protocols;
and, a software/hardware layer that can translate, if necessary,
and re-encode messages from one communications protocol to another
communications protocol. Because modern home networking
technologies can be wireless or PLC based, the protocol translation
device need not be located near any device that it provides
translation services for. The protocol translation device can be
attached to any outlet in the home, such as wall outlet 204
illustrated in FIG. 2A. The protocol translation device can stand
alone or co-reside with a device on the network.
[0171] In an embodiment, a device acts as an information bridge
between two networks. An electric vehicle service equipment (EVSE),
or a charge point, may communicate with an electric vehicle via the
SAEJ2836 application protocol over a HomePlug AV physical
communication mechanism and with a home area network (HAN) using
smart energy application protocol over a ZigBee wireless physical
communication mechanism. Such an EVSE or charge point can implement
the message translation between the two networks. For messages that
have equivalent meanings in both networks, the EVSE can reformulate
the message that comes in from the ZigBee/Smart Energy network to
the format of the J2836/PLC network and transmit the message from
the HAN to the vehicle.
[0172] In another embodiment, the device is a member of two
different networks and the device passes messages back and forth
between the two networks. The networks have some incompatibility,
such as a physical layer or application layer. Smart energy is an
application layer protocol that is implemented for multiple
physical interfaces including ZigBee and HomePlug PLC. The device
can be located such that it is able to participate in both networks
simultaneously. The device may contain the physical equipment to be
able to send/receive messages on either network, such as ZigBee for
wireless and HomePlug PLC for wired. As a message is observed on
either network, the device translates the message to the other
network's physical layer. When both networks implement smart
energy, there is no need to translate the application layer as
well.
[0173] In one embodiment, an electric vehicle service equipment
(EVSE) can act as such a translation device. When a vehicle has the
ability to communicate via one protocol, and an EVSE is located
where access to the central charge management server is provided by
a different protocol, the EVSE could act as a translator between
the two protocols. Such an EVSE includes complete implementations
of both the hardware and software necessary to support both
protocols to fully decode each protocol to obtain the application
level messages.
[0174] An EVSE can be connected to a vehicle using the SAE2836
protocol over PLC and can be connected to a home network using a
wireless ZigBee protocol, according to one embodiment. The EVSE can
include complete implementations of each hardware and protocol
stack. As such, the EVSE can forward messages between the two
stacks.
[0175] In an embodiment, the translation device could be physically
distinct. For example, in an installation with a PLC based vehicle
and a wireless internet access point, the translation device can be
a self-contained box plugged into a power outlet.
[0176] FIG. 11 illustrates an embodiment of a protocol translation
for a power flow management system that utilizes networks to
communicate between electric devices and electric power supplies
1110. A communications protocol translation device reformulates
messages from one protocol to another protocol 1120 in order to
transmit such messages from a network using one communications
protocol to a network using a different protocol. FIG. 12 shows a
communications protocol translation device 1210 implemented between
two networks 1220 that are connected to electric power supplies and
electric devices 1230.
CONCLUSION
[0177] Although systems and methods have been described in language
specific to structural features and/or methodological acts, it is
to be understood that the subject matter defined in the appended
claims is not necessarily limited to the specific features or acts
described. Rather, the specific features and acts are disclosed as
examples of implementations of the claimed methods, devices,
systems, etc. It will be understood by those skilled in the art
that various changes in form and details may be made therein
without departing from the spirit and scope of the invention.
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