U.S. patent application number 10/965805 was filed with the patent office on 2005-03-03 for method of providing service which makes power distribution operation effective, and system.
This patent application is currently assigned to HITACHI, LTD.. Invention is credited to Machitani, Yoichi, Ogura, Nobuyuki, Uchida, Tomonobu.
Application Number | 20050049759 10/965805 |
Document ID | / |
Family ID | 19183565 |
Filed Date | 2005-03-03 |
United States Patent
Application |
20050049759 |
Kind Code |
A1 |
Machitani, Yoichi ; et
al. |
March 3, 2005 |
Method of providing service which makes power distribution
operation effective, and system
Abstract
A method and system for calculating profits shared between a
power distribution company and a service provider, wherein the
power distribution company purchases and resells electric power.
The service provider provides consultation service to the power
distribution company for planning an optimum power distribution
system for increasing power distribution efficiency. The power
distribution company shares profits with the service provider based
on the measured value of the efficiency of the power distribution
operation.
Inventors: |
Machitani, Yoichi;
(Hitachinaka, JP) ; Uchida, Tomonobu;
(Kukizaki-machi, JP) ; Ogura, Nobuyuki; (Hitachi,
JP) |
Correspondence
Address: |
McDermott Will & Emery LLP
600 13th Street, N.W.
Washington
DC
20005-3096
US
|
Assignee: |
HITACHI, LTD.
Tokyo
JP
|
Family ID: |
19183565 |
Appl. No.: |
10/965805 |
Filed: |
October 18, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10965805 |
Oct 18, 2004 |
|
|
|
10315219 |
Dec 10, 2002 |
|
|
|
Current U.S.
Class: |
700/297 ;
700/286 |
Current CPC
Class: |
H02J 3/008 20130101;
G06Q 50/06 20130101; Y04S 10/50 20130101; Y04S 50/10 20130101 |
Class at
Publication: |
700/297 ;
700/286 |
International
Class: |
H02J 003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 10, 2001 |
JP |
2001-375142 |
Claims
1. A power distribution efficiency increasing service providing
method comprising a step for proving an information on an improved
system pattern obtained by modifying a system pattern for reducing
a power loss, for an individual power distribution systems
connected to plural power distributed points; and a step for
measuring and calculating a power loss reduction effect with said
improved pattern.
2. A power distribution efficiency increasing service providing
method of claim 1, wherein a service providing charge corresponding
to said calculated effect is collected from a power distribution
company.
3. A power distribution efficiency increasing method comprising a
step for receiving an information from a service provider company
regarding an improved system pattern obtained by modifying an
existing system pattern in order to reduce a power loss for a power
distribution system connecting plural electric power customers in a
self-owned service area; and a step for paying a charge
corresponding to an estimated value obtained by measuring a power
loss reduction effect brought by said improved system pattern to a
service provider company.
4. A power distribution efficiency increasing service providing
method of claim 1, wherein said power distributed point is an
electric power customer.
5. A power distribution efficiency increasing method of claim 3,
wherein said power distributed point is an electric power
customer.
6. (Cancelled)
7. A power distribution efficiency increasing service providing
method comprising a step for directing to modify a power
distribution system; a step for obtaining a contingent on success
based on a result of measuring an effect of said modification.
8. A power distribution efficiency increasing service providing
method of claim 7, wherein a configuration method for a power
distribution system is obtained so as to reduce a power loss of
said power distribution system by modifying a combination of a
open-circuit state and a closed-circuit state of circuit breakers
or switches in said power distribution system.
9. (Cancelled)
10. (Cancelled)
11. (Cancelled)
12. A power distribution efficiency increasing service providing
method of claim 7, wherein a service provider provide a
consultation for increasing a power distribution efficiency.
13 to 19. (Cancelled).
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to the service for increasing
the efficiency in the power distribution business and its system by
means of minimizing the electric power loss in the power
distribution system or by implementing the plant and equipment
investment effectively for the power distribution system.
[0002] Conventionally, the efficiency increase in the power
distribution operation or the economical operation of the power
distribution operation have depended heavily on the subjective
judgment of the operator. In general, as the power distribution
companies give priority to the reliability of the power
distribution system or the reliability of the electric power supply
rather than its economical operation, it is fact that the
performance and effect in the economical operation has not verified
explicitly.
[0003] It is general that the efficiency increase in the power
distribution operation is provided as a part of the power
distribution efficiency increasing system, in which a relatively
large scale investment on the plant and equipment including the
introduction of the remote-operated circuit breakers and switches
and sensors is assumed.
[0004] In connection with the power liberalization movement, the
importance of strengthening of the baseline of the management
operation increases for the power distribution companies. It is
commonly recognized that the optimization of the plant and
equipment investment and the cost reduction of the electric power
supply are specifically prime tasks among other things.
[0005] And furthermore, as described above, the efficiency increase
in the power distribution operation conventionally depended heavily
on the subjective judgment of the operator and the performance and
effect in the economical operation has not verified explicitly,
which makes an insecure business model.
[0006] In addition, a relatively large scale investment on the
plant and equipment is inevitable for increasing the efficiency in
the power distribution operation.
SUMMARY OF THE INVENTION
[0007] An object of the present invention is to provide a power
distribution efficiency increasing service and a power distribution
efficiency increasing system which enables to increase the
operation of the power distribution without plant and equipment
investment and to verify explicitly its effect (ROI: Return On
Investment) contributing to strengthening the baseline of the
management operation of the power distribution company.
[0008] In order to attain the above object, the power distribution
efficiency increasing service of the present invention comprises a
means for planning the optimum power distribution system to be
established with initial investment by the service provider, a
means for providing a consultation for increasing the efficiency in
the power distribution, a means for introducing the system for
measuring the revenue money obtained by the power distribution
efficiency increasing service and a means for measuring the usage
rate of the optimized power distribution system.
[0009] In addition, in order to attain the above object, the power
distribution efficiency increasing system of the present invention
comprises a measuring device of the purchased power of the power
distribution company, a means for transmitting the measured data of
the purchased power and the operation information of the power
distribution system to the service provider, a means for receiving
the measured data, a computer for calculating the optimum power
distribution system pattern, a computer for calculating the usage
rate of the optimized power distribution system and a computer for
calculating the revenue money obtained by the optimization.
[0010] The other characteristics of the present invention are as
described in the scope of claim for patent, and those
characteristics will be described individually below.
[0011] The power distribution efficiency increasing service
providing method of the present invention is characterized by that
for the individual power distribution systems connected to plural
power distributed points (that is, electric power customer in
principle, and hereinafter referred to as this), the information on
the improved system pattern obtained by modifying the system
pattern for reducing the power loss is provided, and the power loss
reduction effect with this improved pattern is measured and
calculated. In this case, it is preferable that the service charge
corresponding to the calculated effect is collected from the power
distribution company.
[0012] In addition, the power distribution efficiency increasing
service providing method of the present invention is characterized
by that the power distribution system is configured and operated
appropriately (which means to reducing the loss much more, or to
minimize, that is, optimize the loss, and hereinafter, the term of
optimize or optimization will be used for simplifying the
explanation, but the scope of the present invention is not limited
by the term of optimize) and then the contingent on success based
on the measurement result of the optimization effect is obtained.
More specifically, (1) a method is provided for configuring an
optimum power distribution system for minimizing the power loss in
the power distribution system, by modifying the, combination of the
open-circuit state and the closed-circuit state of the circuit
breakers or switches in the power distribution system; (2) a method
is provided for configuring an optimum power distribution system so
as to suspend a plant and equipment investment by modifying the
layout of equipment on the electric circuit including circuit
breakers, switches or other devices forming the power distribution
system, or by removing the equipment; and (3) a method is provided
for configuring an optimum power distribution system in which both
the first pattern for modifying the power distribution system
optimized for reducing the electric power loss in the power
distribution system, obtained by modifying a combination of the
open-circuit state and the closed-circuit state of circuit breakers
or switches in the power distribution system; and the second
pattern for modifying the power distribution system enabled to
suspend a plant and equipment investment by modifying a layout of
equipment on the electric circuit including circuit breakers,
switches or other devices forming the power distribution system, or
by removing the equipment are considered with a predefined
weight.
[0013] Paying attention to the electric power volume purchased from
the power generation company or the power generation division of
the electric company (hereinafter referred directly to as power
generation company) by the power distribution company of the power
distribution division of the electric power company (hereinafter
referred directly to as power distribution company), it is
preferable that the purchased electric power volume before
introducing the power distribution efficiency increasing service
(hereinafter referred directly to as pre-introduction) and the
purchased electric power volume after introducing the power
distribution efficiency increasing service (hereinafter referred
directly to as post-introduction) are measured in a constant period
of time individually, and that the effect brought by the power
distribution efficiency increasing service is estimated based on
the difference between the pre-introduction electric power volume
and the post-introduction electric power volume. It is allowed that
the power generation company is identical to the power distribution
company.
[0014] In addition, it is preferable that the service provider
provides a consultation service for increasing the power
distribution efficiency. In this case, the consultation service
provided to the power distribution company by the service provider
includes timely information service for the comprehensive know-now
for operating the power distribution system such as the supervisory
and control of the power distribution system, the construction and
engineering works for the power distribution lines, the recovery
from the accident in the power distribution system and the
investment program for the power distribution equipment.
[0015] In addition, it is effective that the service provider
implements the initial investment and provides either or both of
the installation of the system for measuring the effect brought by
the power distribution efficiency increasing service and the
production of the software for planning the optimum power
distribution system, and that, as for the contingent on success,
the profit from the power distribution efficiency increasing
service may be shared by the power distribution company and the
service provider or obtained as the service charge. In the later
case, it is specifically effective that the service provider
receives the operation record information from the power
distribution company and estimates the usage rate of the optimum
power distribution system based on this information, and the
service provider may determine alternatively to receive the divided
profit brought by the power distribution efficiency increasing
service or to receive the service charge considering the estimated
usage rate of the optimum power distribution system.
[0016] The power distribution efficiency increasing method of the
present invention is characterized by that the power distribution
company receives the information from the service provider company
regarding the improved system pattern obtained by modifying the
existing system pattern in order to reduce the power loss for the
power distribution system connecting the plural electric power
customers in the service area of the power distribution company,
and that the power distribution company pays the charge
corresponding to the estimated value obtained by measuring the
power loss reduction effect brought by the improved system pattern
to the service provider company. In this case, it is preferable
that the service charge is kept fixed for a constant period of time
negotiated in advance or defined to be a divided amount shared with
the profit of the power distribution company.
[0017] For the power distribution efficiency increasing system, it
is especially effective that (1) the measuring device for the
electric power purchased by the power distribution company is
installed at the power receiving equipment in the power
distribution company importing the electric power from the power
generation company, or (2) the transmitting device and the
receiving device use Internet, the public telephone network or the
private communication network.
[0018] In the claims of the present invention, the term of
optimization includes such a context as the effect of the power
loss reduction could be obtained or expected, and thus, such a case
that a little effect is obtained at all may be included in the
context of optimization as defined in the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is an illustration showing an example of the power
distribution system.
[0020] FIG. 2 is an illustration showing an example of the power
distribution system.
[0021] FIG. 3 is an illustration showing an example of the power
distribution system.
[0022] FIG. 4 is an illustration showing a configuration of the
power distribution efficiency increasing service in one embodiment
of the present invention.
[0023] FIG. 5 is an illustration showing a configuration of the
power distribution efficiency increasing service in one embodiment
of the present invention.
[0024] FIG. 6 is a block diagram illustrating an information flow
in the power distribution efficiency increasing service in one
embodiment of the present invention.
[0025] FIG. 7 is a flowchart illustrating a procedural flow in the
power distribution efficiency increasing service in one embodiment
of the present invention.
[0026] FIG. 8 is a characteristic chart illustrating examples of
time shifting of the summation of the electric power retail sales
contracted volume in the load dispatched area of the base
substation.
[0027] FIG. 9 is a characteristic chart illustrating an example of
time shifting of the summation of the electric power retail sales
contracted volume in the overall load dispatched area covered by
the power distribution efficiency increasing service.
[0028] FIG. 10 is a characteristic chart illustrating an example of
the time shifting of the electric power volume purchased from the
power generation company and its unit price of the purchased
electric power.
DETAILED DESCRIPTION OF THE INVENTION
[0029] Now, referring to FIG. 1 to 3, the present invention is
disclosed in the preferred embodiment. At first, modification of
the power distribution system pattern is described with the
preferred embodiments.
[0030] According to this embodiment, the efficiency of the power
distribution system is increased in the following method. By
modifying the open and close pattern of the circuit breakers or the
switches in the power distribution system, an optimum pattern of
the power distribution system making the electric loss minimized
can be obtained without altering the condition for supplying the
electric power to the electric power customers.
[0031] FIG. 1 shows an example of a part of the power distribution
system to which the efficiency increasing service of this
embodiment is applied, in which what is shown is a part of the
patterned power distribution system comprising power distribution
substation transformer s1 (=BANK01, 02 . . . ), section switches 2
(=TYS01, 02, 03, 04, 05, 06, 07 . . . ), cooperating switches 3
(=TL01 . . . ) and feeder circuit breakers 4 (=FCB01, 02 . . .
).
[0032] The electric power purchased from the power generation
company is supplied from the primary side of the power distribution
substation transformer 1 and its voltage is made reduced and then,
the electric power flows into the power distribution system through
the feeder circuit breakers 4. The section switches 2 and the
cooperating switches 3 in the power distribution system have their
own open-circuit state or closed-circuit state individually, and
define a specific pattern of the power distribution system.
[0033] FIG. 2 shows a route for supplying the electric power to the
load 5 in a given power distribution system pattern. The electric
power is supplied to the load 5 through the route starting at
BANK02 in the power distribution substation transformer 1 connected
next to FCB02 as the feeder circuit breaker 4, connected next to
TYS04 as the section switch 2, connected next to TYS05 as the
section switch and finally through TYS07 as the section switch.
[0034] FIG. 3 shows another example of the route for supplying the
electric power to the load 5 in a given power distribution system
pattern defined by modifying the open and close state of the
section switches 2 different from the example shown in FIG. 2. More
specifically, in the power distribution system in FIG. 3 compared
to what shown in FIG. 2, in which TYS05 as the section switch 2 is
turned from the closed-circuit state to the open-circuit state and
TYS06 as the section switch is turned from the open-circuit state
to the closed-circuit state, resultantly, the electric power is
supplied to the load 5 through the route starting at the BANK01 in
the power distribution substation transformer 1 connected next to
FCB01 as the feeder circuit breaker 4, connected next to TYS01 as
the section switch 2, connected next to TYS02 as the section
switch, connected next to TYS03 as the section switch, connected
next to TL01 as the cooperating switch 3, connected next to TYS06
as the section switch 2 and finally through TYS07 as the section
switch.
[0035] Comparing the case of supplying the electric power through
the route shown in FIG. 2 with the case of supplying the electric
power through the route shown I FIG. 3, it is proved that the
electric loss in the individual route differs from each other due
to the difference in the impedance of the power distribution cable
and the distance between the power source to the load. To obtain an
optimum power distribution system enabling to minimize the power
distribution loss is equivalent to select a single pattern for
minimizing the power distribution loss among several patterns, each
having an individual combination of open and closed states of the
circuit breakers and the switches in the power distribution system
in the area covered by a given service. As the calculation for
selecting an optimum pattern by using a computer consumes an
extended time period, it is general to apply such a method as
Genetic Algorithm (GA algorithm) in order to obtain an approximate
solution in a shorter time period.
[0036] For the supplementary note, the functions of the section
switch 2 and the cooperating switch 3 are described here. Both of
the section switch 2 and the cooperating switch 3 are switches
operating on an electric circuit and have an identical electric
function. Their difference is only determined by their positions
placed in the electric circuit. Their operational roles change in
connection with their positions.
[0037] As for the section switches 2, the electric power customers
are connected to the individual branches in the power distribution
system configured in a tree structure (in which only a single route
is established between the power source to the individual electric
power customer (load)), in which the section switch is located so
as to form an individual small-sized group of customers. For
example, in urban areas, the distribution system is divided into a
set of sections by the section switches, each arranged for 3 to 10
customers. Though all the customers (loads) are not illustrated
explicitly in such a figure as shown by FIG. 1 in general, plural
customers are connected practically to the sections before and
after the individual section switch. In the power distribution
system configured in a tree structure, once the section switch is
turned OFF, the electric power to be supplied to the customers
located in the down stream of this section switch is broken down.
In a practical operation, when an accident occurs in the power
distribution system, the cooperating switches are combined in order
to minimize the area of power failure.
[0038] The cooperating switch 3 is a switch for coupling the
sections of the power distribution system configured in a tree
structure, and is normally turned OFF in Japan. When the
cooperating switch is turned ON, there may occur such a case that
several sections form a loop. This means that plural power supply
routes are formed from the power source to the customer. Owing to
this configuration, the reliability in the power supply can be
increased. In a example of using the cooperating switch, the
cooperating switch is normally turned OFF, and in case that an
accident in the power distribution system occurs, the disabled
section due to the accident is isolated by the section switches and
then the cooperating switch is turned ON, which makes it possible
to supply the electric power from the another section in the
branching power distribution system to the operable sections
located in the down stream of the disabled section due to the
accident.
[0039] It is difficult to establish several alternative routes from
the power source to the customer only by using the section
switches. As alternative power distribution patterns can be
established by supplying the electric power from the other power
sources through the cooperating switches, what can be obtained is
such a pattern of switches individually turned OFF or OFF as
minimizing the power distribution loss can be minimized.
[0040] In the method of one embodiment of the present invention,
the electric power volume purchased from the power generation
company by the power distribution company before and after
introducing the power distribution efficiency increasing service;
the profit money obtained by introducing the power distribution
efficiency increasing service is calculated based on the difference
between the electric power volume before and after its
introduction; the profit money is divided based on the contract
concluded between the power distribution company and the service
provider or the service charge is paid from the power distribution
company to the service provider.
[0041] At first, before introducing the power distribution
efficiency increasing service, the purchased electric power to be
distributed to the service area of the distribution company is
measured in a given time period. Next, the purchased electric power
is measured in a given time period after introducing this service.
The effect of this service is defined as the reduced volume of the
purchased electric power for the power distribution company by
comparing the pre-service operation with the post-service
operation.
[0042] The given time period described above is defined to be long
enough to insensitive to the changes in the power demand due to
days of week, seasons and/or unscheduled events. This given time
period is defined to be one year in the following description.
[0043] Though the effect obtained by the power distribution
efficiency increasing service can be calculated based on the result
of measuring the electric power volume purchased by the power
distribution company as described above, the electric power demand
(or the electric power volume purchased by the power distribution
company) changes irregularly and annually due to the climatic
conditions and the increase and decrease in the number of customers
in general. This change should be considered in calculating the
effect obtained by the power distribution efficiency increasing
service.
[0044] By referring to FIG. 4, one embodiment of the present
invention is described. FIG. 4 is a work flow showing a basic
configuration of the power distribution efficiency increasing
service.
[0045] The contract for the power distribution efficiency
increasing service is concluded between the power distribution
company 1010 and the service provider 1009. The power distribution
company 1010 purchases (1013) the electric power from the power
generation company 1012 and pays (1014) the retail sales
electricity bills to the power generation company 1012. In
addition, the power distribution company 1010 sells (1007) retail
of the electric power to the electric power customer 1011, and
collects (1008) the electricity bills. If the power distribution
company 1010 increases the efficiency in the power distribution
operation, the electric power volume purchased from the power
generation company can be reduced without making effect to the
power supply to the electric power customer 1011. In other words,
it can be interpreted qualitatively that the wholesale electricity
bills to be paid to the power generation company 1012 can be
reduced without sacrificing the collected amount of electricity
bills from the electric power customers 1011, and that the cost
reduction can be realized in the power distribution operation.
[0046] The service provider 1009 initially invests (1004) initial
capital for the plant and equipment to the power distribution
company 1010 according to the contract concluded between the power
distribution company 1010 and the service provider 1009. The
initial capital investment (1004) to the plant and equipment covers
the measuring system for measuring the effect obtained by the power
distribution efficiency increasing service, the construction of the
equipment data base and the installation of the computer system for
calculating an optimum power distribution system pattern, which
will be described later.
[0047] In addition, the service provider 1009 provides (1001) the
consultation for increasing the power distribution efficiency, and
the power distribution company 1010 implements the operation for
increasing the power distribution efficiency and feeds back (1003)
its operation information to the service provider 1009. The
measured values for the electric power volume purchased from the
power generation company 1012 is collected (1002) by the service
provider 1009. The service provider 1009 calculates the profit
money obtained by increasing the power distribution efficiency from
the above information, and notifies (1005) it to the power
distribution company 1010. The service provider 1009 receives
(1006) the divided money corresponding to this profit money or the
fixed service charge from the power distribution company 1010.
[0048] FIG. 5 is a system configuration diagram illustrating one
mode of the embodiment of the present invention. The electric power
generated at the power generation facility 2001 of the power
generation company 1012 is supplied to the power transforming
facility 2005 of the power distribution company through the power
distribution line 2002, and then supplied from the power
distribution system facility 2006 to the electric power customer
1011 through the power distribution line 2003.
[0049] The power distribution system supervisory and control system
2007 supervises and controls the power distribution system facility
2006 and the power transforming facility 2005 in the power
distribution company 1010. The operation information of the power
distribution system facility 2006 is stored in the power
distribution system supervisory and control system 2007. The
electric power volume purchased from the power generation company
1012 by the power distribution company 1010 is measured by the
purchased electric power measuring system 2004. The operation
information of the power distribution system facility 2006 and the
measurement data of the purchased electric power measuring system
2004 are transmitted periodically to the service provider through
the communication unit 2010, and the public network or the private
network 2011.
[0050] The service provider 1009 has the communication unit 2009
and receives the data from the power distribution company 1010. In
addition, the service provider has the computer 2008, in which an
optimum power distribution system pattern is calculated, the usage
rate of the optimized power distribution system and the profit
money obtained by the optimization is calculated.
[0051] FIG. 6 is a block diagram showing the information flow in
one embodiment of the power distribution efficiency increasing
service in the present invention
[0052] In the power distribution company 1010, the power
distribution system supervisory and control system 2007 supervises
and controls the power distribution system by using the facility
information data base 3008, and the operation information is stored
in the facility information data base 3008. The data of the
purchased electric power volume obtained by the purchased electric
power measuring system 2004 are transmitted to the service provider
1009 through the communication units 2010 and 2009.
[0053] In the service provider 1009, the estimated value of the
usage rate of the optimized power distribution system is calculated
3003 based on the data received by the communication unit 2009 and
the result of the calculation 3002 for estimating the optimum power
distribution system pattern. The calculation 3002 for estimating
the optimum power distribution system pattern is based on the
facility information stored in the facility information data base.
The facility information includes the impedance of the power
distribution lines and the position or distance information of the
loads, the circuit breakers and the switches in the individual
power distribution systems. The information stored in the facility
information data base 3008 is supplied in an on-line or off-line
mode to the calculation 3002 for estimating the optimum power
distribution system pattern at the service provider 1009. The data
obtained by the calculation 3002 for estimating the optimum power
distribution system pattern are stored in an on-line or off-line
mode into the facility information data base 3008 and then used for
operating the power distribution system.
[0054] The calculation 3001 for estimating the profit money
obtained by optimization is executed based on the data obtained by
the calculation 3003 for estimating the usage rate of the optimized
power distribution system and the operation information of the
power distribution system and the purchased electric power volume
received through the communication unit 2009.
[0055] FIG. 7 is a flow chart showing a procedural flow of the
power distribution increasing service in the embodiment
illustrating one mode of the present invention. At first, the
service provider 1009 surveys and studies the purchased electric
power volume of the power distribution company and its power
distribution system configuration, and forecasts the profit to be
obtained by introducing the service (Step i). Next, the service
provider 1009 provides the power distribution company 1010 with the
consultation for introducing this service (Step ii). Next, the
contract for this service is concluded (Step iii).
[0056] After concluding the contract, the system for measuring the
effect obtained by increasing the power distribution efficiency is
installed (Step iv). Next, the consultation for increasing the
power distribution efficiency is provided to the power distribution
company by the service provider 1009.
[0057] Next, the power distribution company implements the
operation for increasing the power distribution efficiency (Step
vi), and then the usage rate of the optimized power distribution
system provided by the service provider and the effect obtained by
increasing the power distribution efficiency are measured (Step
vii).
[0058] Thereafter, whether the optimized power distribution system
was used in a contracted usage rate or more is judged (Step viii),
and if the usage rate does not reach a designated value, the profit
money obtained by the service is divided appropriately as
contracted between the power distribution company 101 and the
service provider 1009, or the power distribution company 1010 pas
the service charge to the service provider 1009 (Step ix). If the
usage rate reaches or exceeds a designated value, the profit money
obtained by the service is divided approximately as contracted
between the power distribution company 101 and the service provider
1009, or the power distribution company 1010 pas the service charge
to the service provider 1009.
[0059] Though thee outline of the power distribution efficiency
increasing service and the power distribution efficiency increasing
system is described above, what will be described concretely below
is a method for correcting the measured value of the electric power
volume purchased from the power generation company 1012 by the
power distribution company 1010 and estimating the effect of the
service.
[0060] Assume that the number of the power distribution substations
located in the area covered by the service is n. Plural substations
extracted randomly from the power distribution substations located
in this service area or located in the areas adjacent to this
service area are called base stations. Assume that the number of
the base stations is m. The service is not applied to m base
stations. In this condition, the electric power inflow into m base
stations does not change before and after introducing the service,
and thus is not influenced by the introduction of the service. In
the following description, suppose at first such a case that the
number of electric power customers does not change in order to
simplify the explanation.
[0061] Year.sub.1 represents a single year before introducing the
service and Year.sub.2 represents a single year after introducing
the service. The ratio of the electric power flowing into the base
stations in the period of Year.sub.1 to the electric power flowing
into the base stations in the period of Year.sub.2 is supposed to
be equal in a certain error range to the ratio of the electric
power volume purchased by the power distribution company in the
period of Year.sub.1 covered by the introduced service to the
electric power volume purchased by the power distribution company
in the period of Year.sub.2 without introducing the service.
[0062] The power distribution company 1010 and the service provider
1009 agree as contracted that the error between the ratios defined
above is negligibly small enough, and that the effect of the
service is estimated based on the ratio of the electric power
flowing into the base stations before and after introducing the
service.
[0063] Suppose that PB.sub.year1 is the electric power volume
purchased by the power distribution company 1010 in a single year
(Year.sub.1) before introducing the service, PB.sub.year2 is the
electric power volume purchased by the power distribution company
1010 in a single year (Year.sub.2) after introducing the service,
PB'.sub.year2 is the electric power volume purchased by the power
distribution company 1010 in a single year (Year.sub.2) without
introducing the service, PI.sub.before is the electric power
flowing into the base stations in Year.sub.1, PI.sub.after is the
electric power flowing into the base stations in Year.sub.2, the
ratio of PI.sub.after to PI.sub.before is equal to the ratio Rbase
between the changes in the electric power demand in Year.sub.1 and
Year.sub.2 due to the climatic condition independent of the
introduction of the service. 1 R base = PI after PI before ( 1
)
[0064] Then, in case that the service is not introduced in the
period of Year.sub.2, the ratio R of the electric power purchased
from the power generation company by the power distribution company
in the period of Year.sub.2 to the electric power purchased in the
period of can be expressed in the following formula. 2 R = PB year2
' PB year1 = R base + Err ( 2 )
[0065] Supposing that the ratio of the efficiency increased by the
service is Rservice (0.ltoreq.service<1) and assuming that Err=0
in the formula 2, the following equation is satisfied.
PB.sub.after=PB.sub.before.times.R.sub.base.times.(1-R.sub.service)
(3)
[0066] Next, Let us consider the increase or decrease in the number
of the electric power customers, that is, the increase or decrease
in the summation of the contracted volume of the retail electric
power.
[0067] At first, let us pay attention to R.sub.base. As shown in
FIG. 8, defining the change in the summation of the contracted
volume of the retail electric power in the power distribution area
of the base station to be a function F.sub.c1(t), the ratio
R'.sub.base between the changes in the electric power demand in the
periods of Year.sub.1 and Year.sub.2 due to the climatic condition
independent of the introduction of the service for considering the
above described correction can be expressed in the following
formula. 3 R base ' = t0 t1 F c1 ( t ) t t1 t2 F c1 ( t ) t .times.
R base ( 4 )
[0068] Similarly, as shown in FIG. 9, defining the change in the
summation of the contracted volume of the retail electric power in
the overall area of the service to be a function F.sub.c2(t), the
formula 3 defined above can be expressed in the following formula.
4 PB after = t0 t1 F c2 ( t ) t t1 t2 F c2 ( t ) t = PB before
.times. R base ' .times. ( 1 - R service ) . ( 5 )
[0069] Above expressions are based on such an assumption that the
electric power demand due to the increase or decrease in the number
of the electric power customers is proportional to the summation of
the contracted volume of the retail electric power. 5 C 2 = t0 t1 F
c2 ( t ) t t1 t2 F c2 ( t ) t ( 6 )
[0070] The formula 6 gives the following formula. 6 R service = PB
after PB before .times. C 2 R base ' - 1 ( 7 )
[0071] The value obtained by multiplying the cost of the electric
power purchased by the power distribution company in the period of
Year.sub.2 by R.sub.service as defined above is the profit money
Y.sub.profit obtained by introducing the service.
[0072] As shown in FIG. 10, suppose that the change in the unit
price of the electric power purchased from the power generation
company 1012 by the power distribution company 1010 is a function
Fp(t), and that the change in the purchased electric power volume
is expressed by function Fb(t), the profit money Yprofit obtained
by introducing the service can be expressed by the following
formula. 7 Y profit = t1 t2 [ F p ( t ) .times. F b ( t ) ] t
.times. R service ( 8 )
[0073] The profit money as defined above is divided between the
power distribution company 1010 and the power generation company
1009 according to the contract concluded between them.
[0074] In the service, it is required to make it a necessary
condition to apply such an optimum power distribution network as
described above with minimum power distribution loss to the
practical power distribution operation in the service period of
Year.sub.2. This is because the practical power distribution
operation is based on the subjective decision by the operators of
the power distribution company 1010 with overall estimation of the
economical efficiency, the reliability of the power distribution
system, the reliability of the power supply and the easiness in the
operation, and furthermore because the reliability of the power
distribution system and the reliability of the power supply have a
higher priority than the economical efficiency of the
operation.
[0075] In case that the occurrence of applying the optimum
distribution system with the minimum distribution loss in the
period 1 is extremely low, the profit money Yprofit obtained by the
service may be extremely low or it may be zero or negative in some
occasions. For this reason, the lower bound Pmin for the occurrence
of applying the optimum distribution system to the practical power
distribution operation is determined in advance according to the
contract concluded between the power distribution company 1010 and
the power generation company 1009, and if
P.sub.applied.gtoreq.P.sub.min, the profit money Y.sub.profit
obtained by the service is divided between the power distribution
company 1010 and the service provider 1009 based on the contract
concluded between them as described above. On the other hand, if
P.sub.applied<P.sub.min, the power distribution company 1010
pays the service charge for the service provided by the service
provider 1009 in the periods of Year.sub.1 and Year.sub.2 to the
service provider 1009 instead of dividing the profit money
independent of the profit money Y.sub.profit being larger or small,
or positive or negative.
[0076] The method of calculating P.sub.applied, the occurrence of
applying the optimum distribution system to the practical power
distribution operation, is described below.
[0077] In this embodiment, the method of calculating P.sub.applied
is based on the difference between the power distribution loss
W.sub.actual in the actual power distribution system and the power
distribution loss W.sub.min in the optimum power distribution
system. As for the power distribution loss, the power distribution
loss w1 for the single-phase wire system is generally obtained by
the formula 9, and the power distribution loss for the three-phase
three-wire system is generally obtained by the formula 10. Suppose
that the load power is P, the line-to-line voltage is V, the load
power factor is cos .theta., and the wiring impedance is R. 8 w1 =
21 2 R = 2 ( P V cos 0 ) 2 R = 2 P 2 R V 2 cos 2 0 ( 9 ) w3 = 31 2
R = 2 ( P 3 V cos 0 ) 2 R = P 2 R V 2 cos 2 0 ( 10 )
[0078] Once the open-circuit and closed-circuit states of all the
circuit breakers and the switches of the power distribution system
in the service area, the summation of the power transmission loss
in the actual power distribution system, W.sub.actual, and the
summation of the theoretical power distribution loss, W.sub.min, in
case of applying the optimum distribution system is applied fully
to the load in the actual power distribution system can be
obtained.
[0079] The occurrence of applying the optimum power distribution
system to the actual power distribution system, P.sub.applied, can
be defined as in Formula 11, by using W.sub.actual and W.sub.min. 9
P applied = 1 - W actual - W min W min ( 11 )
[0080] Next, the occurrence of applying the optimum power
distribution system to the actual power distribution system,
P.sub.applied.sub..sub.ye- ar2, for the overall period of
Year.sub.2 is calculated.
[0081] Assuming that the power distribution loss in the actual
power distribution system in a given day (day=i) is
W.sub.actual(i), and the theoretical power distribution loss in
case of operating the load with the optimum power distribution
system, P.sub.applied.sub..sub.year2 is obtained by Formula 12. 10
P applied_year2 = 1 - day = 1 366 W actual ( day ) - day = 1 365 W
min ( day ) day = 1 365 W min ( day ) ( 12 )
[0082] As described above, according to the present invention, the
power distribution efficiency increasing service and the power
distribution efficiency increasing system which can increase the
efficiency of the power distribution operation without plant and
equipment investment, and contribute to strengthening the baseline
of the management operation of the power distribution company can
be provided.
* * * * *