U.S. patent application number 14/682061 was filed with the patent office on 2016-08-18 for power and communication distribution topology for heliostats.
This patent application is currently assigned to eSolar Inc.. The applicant listed for this patent is eSolar Inc.. Invention is credited to Jason Blair, Carl Wing-Jang Chin, Parsa Dormiani.
Application Number | 20160238282 14/682061 |
Document ID | / |
Family ID | 56622067 |
Filed Date | 2016-08-18 |
United States Patent
Application |
20160238282 |
Kind Code |
A1 |
Chin; Carl Wing-Jang ; et
al. |
August 18, 2016 |
Power and Communication Distribution Topology for Heliostats
Abstract
A network topology for powering and communicating with groups of
heliostats in a concentrated solar power plant. Heliostats are
arranged in rows and wired together with inter-drive cables that
distribute power and data from a field electrical system and plant
network. Data is transmitted to and from heliostat drive control
boards via network switches connected to intelligent power
distribution units. Power is transmitted from battery banks to said
intelligent power distribution units. Communication interface
modules supply a connection between intelligent power distribution
units and the heliostat control boards of non-adjacent heliostat
rows to create communication and data loops having improved
redundancy and robustness in the event of single point component
failures.
Inventors: |
Chin; Carl Wing-Jang; (Santa
Monica, CA) ; Blair; Jason; (La Crescenta, CA)
; Dormiani; Parsa; (San Mateo, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
eSolar Inc. |
Burbank |
CA |
US |
|
|
Assignee: |
eSolar Inc.
Burbank
CA
|
Family ID: |
56622067 |
Appl. No.: |
14/682061 |
Filed: |
April 8, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61976906 |
Apr 8, 2014 |
|
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|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F24S 23/70 20180501;
Y02D 50/30 20180101; Y02D 30/50 20200801; F24S 2030/10 20180501;
F24S 30/40 20180501; H04L 12/40 20130101; Y02E 10/47 20130101; F24S
2023/87 20180501; H04L 12/10 20130101; F24S 50/20 20180501 |
International
Class: |
F24J 2/38 20060101
F24J002/38 |
Claims
1. A system for powering and controlling a heliostat field,
comprising: a plant network; a plurality of network switches
connected to the plant network, wherein each network switch has a
plurality of ports; at least one intelligent power distribution
unit comprising a plurality of intelligent power distribution
cards, wherein each intelligent power distribution card is
connected to at least one other intelligent power distribution card
and is connected to a port on one of the plurality of network
switches; at least one communication interface module connected to
at least one of the plurality of intelligent power distribution
cards; a plurality of heliostats connected to each other and
arranged in rows, wherein the heliostats comprise reflectors and
controllers; and wherein at least one heliostat controller in each
row is connected to a communication interface module.
2. The system of claim 1, wherein adjacent intelligent power
distribution cards in an intelligent power distribution unit are
connected to different network switches.
3. The system of claim 2, wherein each communication interface
module is connected to a heliostat controller of up to four
heliostat rows.
4. The system of claim 3, wherein each communication interface
module is configured to supply power and data communication to each
connected heliostat in a row.
5. The system of claim 4, wherein heliostats in pairs of adjacent
rows connected to the same communication interface module are
connected together in parallel to create power transmission loops
that comprise the communication interface module and all heliostat
controllers in said pairs of adjacent rows.
6. The system of claim 5, wherein a power transmission loop
provides an alternate power transmission pathway to all heliostats
in said loop during a failure event.
7. The system of claim 4, wherein heliostats in pairs of adjacent
rows connected to the same communication interface module are
connected together in a daisy-chain to create communication
transmission loops that comprise the communication interface module
and all heliostat controllers connected to said communication
interface module.
8. The system of claim 7, wherein a communication transmission loop
provides an alternate communication transmission pathway to all
heliostats in said loop during a failure event.
9. The system of claim 8, wherein the communication interface
module further comprises a plurality of microcontrollers.
10. The system of claim 9, wherein the communication interface
module microcontrollers that connect to adjacent heliostat rows are
connected to different intelligent power distribution cards.
11. The system of claim 10, wherein the intelligent power
distribution cards are connected to different network switches.
12. The system of claim 1, wherein the heliostats are connected to
each other via inter-drive cables that interface with the heliostat
controllers.
13. The system of claim 12, wherein the inter-drive cables comprise
both power and data distribution wires.
14. The system of claim 2, wherein the network switches are
connected to each other in series using auxiliary data
connectors.
15. The system of claim 14, wherein the auxiliary data connectors
further comprise Ethernet cables.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] The present application claims priority to and the benefit
of U.S. Provisional Patent Application No. 61/976,906, filed on
Apr. 8, 2014, the entire disclosure of which is incorporated herein
by reference.
BACKGROUND OF THE INVENTION
[0002] This disclosure relates generally to the power and
communication delivery system for heliostats having reflectors for
use in redirecting sun light to a target or receiver. In
particular, the invention relates to a heliostat field having
wiring loops and network topology to facilitate a system with
multiple stages of redundancy.
[0003] In Concentrating Solar Power (CSP) plants, arrangements of
heliostats reflect sunlight toward a receiver mounted atop a tower
containing a working fluid. One type of receiver transfers incident
radiant energy to the working fluid to produce high-pressure,
high-temperature steam through the means of a heat exchanger or a
phase change of the working fluid itself. The working fluid can be
water, air, or a salt material heated to a molten state. The output
steam can facilitate a variety of applications, such as electrical
power generation, enhanced oil recovery, and desalination.
Heliostats are generally mounted on the ground in an area about the
tower. Each heliostat has a rigid reflective surface, such as a
mirror, capable of sun-tracking, wherein the reflective surface
takes on orientations throughout the day so as to optimally
redirect sun light from the sun toward the receiver. Arrays of
heliostats may be arranged into a plurality of subgroups comprising
a field. The subgroups may be configured to provide a preferred
orientation that facilitates efficient land usage, optimizes the
amount of flux delivered to the receiver, and minimizes the
blocking of outer heliostats by inner heliostats.
[0004] One approach to constructing a heliostat field is to utilize
a small amount of comparatively large heliostats (e.g., greater
than between about 50 and 150 m.sup.2). In such a power plant, the
fewer number of heliostats can make it economical to manufacture
very precise, and thus very expensive, components for the
positioning of the reflective surfaces. Another approach, however,
is to use a large amount of comparatively small heliostats (e.g.,
between about 1 and 10 m.sup.2), such as with reflective surfaces
that measure between about 1 meter and 3 meters on each side. Such
an approach may be more efficient at redirecting sun light because
there are more individually adjustable reflective surfaces. In
addition, smaller heliostats are easier to assemble, thereby
decreasing installation time and the amount of requisite labor
[0005] Heliostats may be controlled by a drive comprising a one or
two-axis tracker that tracks the sun and reflects sunlight onto a
target. Heliostats may comprise drive control boards that accept
commands from a controller and operate one or more actuators, such
as motors. A heliostat may have a data and a power connection in
order to direct the drive to a desired orientation. The power
connection provides an energy path to the actuators and control
boards of the heliostat drive. The data connection provides a
communication pathway to the heliostat drive from a central or
distributed controller. Power and communication connections may be
provided using field cabling wired from central power distribution
units and networking hubs, respectively, to individual heliostats
in the field.
[0006] The routing of field cabling to thousands of actuating
devices presents unique challenges and opportunities for
improvement. Rows or subgroups of heliostats may receive power from
a single bus while drive control boards may be connected in series
to establish a communications network. Heliostats may have their
data and communication delivery cables chained together, such that
the same transmission line supplies power and facilitates data
throughput to multiple units in a single subgroup. Such a
configuration presents the possibility of cutting power and
communication to an entire subgroup or a substantial portion
thereof in the event a single component in the chain malfunctions.
Components that could fail during the lifetime of the plant
include, but are not limited to: connector wires, data and power
transmission cables, power supplies, transceivers, and network
switches. There exists a need to reduce the vulnerability of
heliostat electronics topology to single point failures by
incorporating redundant data and communication transmission
pathways.
SUMMARY OF THE INVENTION
[0007] A system for powering and controlling a heliostat field is
described herein, wherein the system comprises a power and
communication network topology having multiple transmission
pathways looped between adjacent heliostat subgroups. The system is
thereby configured to advantageously reduce the impact of single
point failures on plant operation.
[0008] The power and communication distribution network comprises
both electronics hardware and controller software configured to
operate said hardware. Heliostats in a field may be positioned into
subgroups oriented to reflect sunlight onto one of a plurality of
solar receivers and may be deployed in rows or other suitable
arrangements. Each heliostat comprises a reflector and a
controller. The controllers in adjacent heliostats in a row may be
connected to each other via inter-drive cable, wherein an
inter-drive cable facilitates both communication and power-delivery
via constituent wiring.
[0009] A single heliostat in each row may be connected to a
Communication Interface Module (CIM), the CIM being capable of
interfacing in this manner with up to four heliostat rows
simultaneously. This single heliostat may be the heliostat in the
row that is closest to the CIM or closest to the end of the row.
Each communication interface module is configured to pass along
power and data communication to each connected heliostat in a row.
The CIM may be further connected by way of field-routed cables to
an Intelligent Power Distribution Unit (IPDU) housed in a Field
Electrical Cabinet (FEC). Each IPDU may comprise a plurality of
Intelligent Power Distribution Cards (IPDCs). Each CIM may be
connected to a plurality of IPDCs; in this manner a single IPDU can
deliver data and power to multiple CIMs. In a particular embodiment
of the present invention, a CIM may be connected to adjacent IPDCs
housed in the same IPDU. In an alternative embodiment, a CIM may be
connected to IPDCs in different IPDUs. IPDCs in an IPDU may have
network connections to each other, for instance adjacent IPDCs in
an IPDU may be connected. Each IPDC in an IPDU may have a further
connection by way of data-transmission cabling to a port of one of
a plurality of network switches, the network switches being
connected to each other in series via auxiliary data connectors and
also to a plant network. The plant network may comprise additional
communication pathways to a master power plant controller as well
as monitoring systems. Commands issued to individual heliostats may
originate from a control system within the plant network and may be
delivered via the communication distribution topology described
herein.
[0010] As described previously, a centralized power and data
distribution network for controlling thousands of individual
heliostats is vulnerable to single point component failures. In
order to increase the reliability of the system, power and
communication loops may be created to provide redundant pathways
for distribution in the event of aberrant breakdowns or power loss.
One such redundancy may be created with the provision that no two
adjacent IPDCs in an IPDU will be connected to the same network
switch. If a connection between network switches fails, the IPDCs
in an IPDU can still access the Plant Network through an auxiliary
switch.
[0011] As described above, each CIM may supply power and data
communication to up to four rows of heliostats by interfacing with
the inter-drive cable from the heliostat at the proximate end of
each row. DC power may be delivered from a DC power source in the
plant electrical network to an IPDU, where it is then transmitted
to the CIM and the Drive Control Boards (DCBs) in the heliostats.
Heliostats in a pair of adjacent rows may be connected in parallel
to form a power transmission loop. Data may be delivered to and
from the plant network through the network switches to an IPDU,
where it is then transmitted between the IPDCs and CIM and finally
between the CIM and the DCBs in the heliostats.
[0012] In a preferred embodiment, the CIM may have one
microcontroller per row to provide data communication (four
microcontrollers in total). Each CIM microcontroller may provide a
data communication pathway between a communication port on the IPDC
(via field cable) and the first heliostat in a row (via inter-drive
cable). The cables may be connected such that heliostats in
adjacent rows connect to communication ports on different IPDCs.
Additionally the outermost DCBs (furthest from the CIM) of two
adjacent heliostat rows may be connected to each other via
inter-drive cabling to create a power and communication
transmission loop. In this manner data communication pathways are
never interrupted by the failure of single component. In the event
of a microcontroller failure, malfunctioning transceiver, or
damaged microcontroller power supply, data may still be transmitted
to the heliostats of all four rows. The result is an added element
of redundancy to the system to mitigate the effects of component
failures. In an alternative embodiment a single CIM may be used to
facilitate data transfer to less than four heliostat rows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIGS. 1A-1B are isometric and side views, respectively, of
heliostats comprising reflectors mounted to two-axis drive
assemblies.
[0014] FIG. 2 is a systems-level view of the communication and
power distribution topology and delivery pathways for a heliostat
field in a concentrated solar power plant during normal
operation.
[0015] FIG. 3 is a systems-level view of the communication and
power distribution topology and delivery pathways for a heliostat
field in the event of an inter-drive communication link
failure.
[0016] FIG. 4 is a systems-level view of the communication and
power distribution topology and delivery pathways for a heliostat
field in the event of a CIM microcontroller failure.
[0017] FIG. 5 is a systems-level view of the communication and
power distribution topology and delivery pathways for a heliostat
field in the event of a failure of at least one DCB.
[0018] FIG. 6 is a systems-level view of the communication and
power distribution topology and delivery pathways for a heliostat
field in the event of an inter-drive power link failure.
[0019] FIG. 7 is a systems-level view of the communication and
power distribution topology and delivery pathways for a heliostat
field in the event of a network switch failure.
[0020] FIG. 8 is a systems-level view of the communication and
power distribution topology and delivery pathways for a heliostat
field in the event a connection between network switches fails.
[0021] FIG. 9 is a systems-level view of the communication and
power distribution topology and delivery pathways for a heliostat
field in the event of an IPDC to CIM communication link
failure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] FIGS. 1A and 1B display examples of heliostats operated
under the present network and power distribution topology. FIG. 1A
is a perspective view of a subgroup of three heliostats, while FIG.
1B is a side view of the same subgroup. Each heliostat 10 may
comprise a reflector module 11 attached to a reflector module
channel 12 of drive 13. The reflector module may have a planar
shape, such as a flat quadrilateral, or a non-planar shape such as
a concave parabolic dish. The reflector module may also comprise a
plurality of segmented reflectors arranged in a planar or
non-planar shape. The drive 103 may comprise two gear boxes and
motors that actuate the drive about two axes. The axes may be in
the azimuth (orthogonal to the ground) and elevation (orthogonal to
the azimuth axis along the length of the reflector module channel)
directions, or they may be linearly independent axes as, for
example, in a Tilt-Tilt configuration. The drive 102 may interface
with a post 104 of a heliostat structure assembly 105. Heliostat
structure assemblies may be arranged in triangles or other suitable
shapes. Heliostats may further comprise drive control boards
("DCBs", not shown) internal to the drive that receive power,
actuate the motors, and facilitate data communication to and from a
plant network. Actuation commands may be issued to the heliostats
over the plant network from a control system.
[0023] FIG. 2 displays a systems-level view of a heliostat field
power and communication distribution network. Commands to actuate
the heliostat field originate from control systems on the Plant
Network 101 and are transmitted over network data transmission
cables 107. The network data transmission cables 107 connect the
Plant Network 101 to at least one network switch 104. Network
switches may comprise a plurality of ports and may be connected to
each other via auxiliary data connectors 105. IPDCs 103 are housed
in IPDUs 102 and connect to the network switches via IPDC data
transmission cables 106. The network data transmission cables 107,
the auxiliary data connectors 105, and the IPDC data transmission
cables 106 may all comprise different types of cable or cables of
the same type, for example ethernet cable.
[0024] Each IPDU 102 is a chassis for housing a plurality of
modular IPDCs 103, wherein each IPDC comprises an electronics board
for delivering power and data communication to four
microcontrollers 110 in a CIM 109. Adjacent IPDCs within an IPDU
may have network connections 120 to each other. The CIM acts as a
"pass-through", passing power and data to the DCBs 108 of
heliostats in the heliostat field. Heliostats are mounted on
structures 114 having an alternating tripod pattern, wherein the
tripod configuration comprises members of two adjacent heliostat
rows.
[0025] Power and data connections between the CIMs and the IPDCs
are made via field cables 118. Power and data connections between
the CIMs and heliostats, between adjacent heliostats in a heliostat
row, and between heliostats in adjacent rows are made via
inter-drive cables. Both field cables and inter-drive cables
comprise communication delivery wires 111 and power delivery wires
112. The field cables comprise one set of power delivery wires and
two sets of communication delivery wires. The inter-drive cables
comprise one set of power delivery wires and one set of
communication wires. Field cables and inter-drive cables may
comprise different gauge wires. For instance, the field cables may
have a higher gauge wire than the inter-drive cables. In field
cables and inter-drive cables both types of wire may be sheathed to
form a single cable. Inter-drive cables may comprise coupling
connectors on at least one end that can attach to compatible
coupling connectors connected to DCBs 108 installed in the
heliostats. Communication delivery wires 111 may be twisted pair
wires or single-ended wires and may be shielded, for example with
plastic material. All data communication pathways are
bi-directional, for example the DCBs may send data up to the Plant
Network via the CIM and IPDCs.
[0026] As described previously, field cables 118 connect the IPDCs
103 to a plurality of CIMs 109. Each IPDC comprises an electronics
board, a microcontroller, two data communication ports, and PCB
connectors for connecting to power delivery wires and communication
delivery wires in a field cable. An IPDC may have the additional
functions of converting data communication signals to and from the
plant network and of monitoring power distribution. Each data
communication port on an IPDC connects to one of two sets of
communication delivery wires in a field cable. Each CIM comprises
an electronics board, microcontrollers 110, and PCB connectors 119
for passing through power and data communications from the IPDCs
103 to the DCBs 108. The CIMs facilitate the field termination of
field cables from the IPDC and the inter-drive cables from the
heliostats and may comprise resistors for minimizing signal
reflection over long transmission distances. In a preferred
embodiment, each CIM interfaces with four rows of heliostats by
connecting to four separate DCBs via inter-drive cables.
Communication delivery wires 111 in the inter-drive cables connect
a microcontroller 110 in a CIM to the first heliostat of a row,
wherein the first heliostat is the closest heliostat to the CIM of
the heliostats in the row. The communication delivery wires 111 in
the first field cable connect to the CIM microcontrollers for rows
N and N+2. The communication delivery wires 111 in the second field
cable connect to the CIM microcontrollers for rows N+1 and N+3.
[0027] In a preferred embodiment, the outermost DCBs 108 of two
adjacent heliostat rows may be connected via inter-drive cabling to
create a communication transmission loop 113 or 117. Adjacent DCBs
in a heliostat row or between heliostat rows are connected to each
other in a "daisy chain" for the purposes of data transmission. As
visible in FIG. 2, Communication Loop 113 comprises the first data
communication port on each IP DC, two CIM microcontrollers, and all
the heliostats in Row N and Row N+1. Communication Loop 117
comprises the second data communication port on each IPDC, two CIM
microcontrollers, and all the heliostats in Row N+2 and Row N+3. In
this manner data communication pathways are never interrupted by
the failure of a single component in the communication loop. In the
event of a microcontroller failure, malfunctioning transceiver,
damaged microcontroller power supply, or communication delivery
wire failure, data can still be transmitted from the plant network
to the heliostats of all four rows by routing through the
communication loop in the opposite direction. In an alternative
embodiment a single CIM may be used to facilitate data transfer to
less than four heliostat rows.
[0028] In a preferred embodiment, the outermost DCBs 108 of two
adjacent heliostat rows may be connected via inter-drive cabling to
create a power transmission loop 115 or 116. Adjacent DCBs in a
heliostat row or between heliostat rows may be connected to each
other in a "daisy chain" for the purposes of power transmission. As
visible in FIG. 2, Power Loop 115 comprises the CIM and heliostats
in Row N and Row N+1. Power Loop 116 comprises the CIM and
heliostats in Row N+2 and Row N+3. In this manner power
transmission pathways are never interrupted by a single break in
the power loop. DC power is ultimately delivered to a pair of
heliostat rows from the DC power source for the IPDC via power
delivery wires in the field cables that connect an IPDC to a CIM.
The DC power source may have a battery bank backup for added
reliability.
[0029] FIG. 3 displays the same network topology as shown in FIG. 2
as well as the data communication pathway in the event that a
communication link failure occurs between two DCBs of adjacent
heliostats in a row or between the DCBs of heliostats at the end of
two adjacent rows (failure is shown to be occurring in row N+2).
Possible failure modes may include a damaged or worn out connector,
damage to the cable wires themselves, or damage to a communication
transceiver. Under these conditions a communication pathway (shown
as a bold line) is still maintained to all DCBs in Rows N+2 and
N+3. The third CIM microcontroller 110 provides a data
communication pathway for the first DCB of Row N+2. The fourth CIM
microcontroller provides a data communication pathway for all DCBs
in Row N+3 and the remaining DCBs in Row N+2 via the inter-drive
cable that connects the outermost DCBs of Rows N+2 and N+3.
[0030] FIG. 4 displays the same network topology as shown in FIG. 2
as well as the data communication pathway in the event a CIM
microcontroller fails (shown to be occurring in row N). Under these
conditions a communication pathway (shown as a bold line) is still
maintained to all DCBs in Rows N and N+1. The second CIM
microcontroller 110 provides a data communication pathway for all
DCBs in Row N+1 and all DCBs of Row N via the inter-drive cable
that connects the outermost DCBs of Rows N and N+1.
[0031] FIG. 5 displays the same network topology as shown in FIG. 2
as well as the data communication pathway in the event of a DCB
failure (shown to be occurring in row N+2). Possible failure modes
include a malfunctioning DCB power supply or failure of the DCB
microcontroller. Under these conditions a communication pathway
(shown as a bold line) is still maintained to all functioning DCBs
in Rows N+2 and N+3. The third CIM microcontroller 110 provides a
data communication pathway for the DCBs in Row N+2 from the first
DCB connected to the CIM to the DCB immediately before the failed
DCB. The fourth CIM microcontroller provides a data communication
pathway for all DCBs in Row N+3 and the outermost DCB in Row N+2
via the inter-drive cable that connects the outermost DCBs of Rows
N+2 and N+3.
[0032] FIG. 6 displays the same network topology as shown in FIG. 2
as well as the power delivery pathway in the event of a power link
failure between two adjacent DCBs within a power loop (the failure
is shown to be occurring in power loop 116). Possible failure modes
may include faulty connectors at either end of the power delivery
wires 112 or damage to the power delivery wires themselves. The
third CIM inter-drive cable provides a power delivery pathway for
the first DCB of Row N+2. The fourth CIM inter-drive cable provides
a power delivery pathway for all DCBs in Row N+3 and the remaining
DCBs in Row N+2 via the inter-drive cable that connects the
outermost DCBs of Rows N+2 and N+3.
[0033] FIG. 7 displays the same network topology as shown in FIG. 2
as well as the data communication pathway in the event of a network
switch failure. Possible failure modes include damage to
connectors, cables, and a malfunction of the network switch.
Because all of the network switches have redundant access to the
plant network by virtue of their connections to multiple switches,
a communication pathway (shown as a bold line) can still be
established from the IPDC in the IPDU to an active switch via the
network connection 120 between IPDCs.
[0034] FIG. 8 displays the same network topology as shown in FIG. 2
as well as the data communication pathway in the event a connection
between network switches fails. As described with reference to FIG.
7, a communication pathway (shown as a bold line) can still be
established from the IPDC to an active switch with access to the
plant network as a result of redundant connections between active
switches.
[0035] FIG. 9 displays the same network topology as shown in FIG. 2
as well as the data communication pathway in the event of a
communication link failure between an IPDC and a CIM. Possible
failure modes include failure of the network switches,
transceivers, local power supplies, microcontrollers, connectors,
or the communication delivery wires. A communication pathway (shown
as a bold line) can still be established from the still-functional
IPDC to DCBs for all heliostats in the four rows of heliostats
connected to the CIM.
* * * * *