JP2004274812A - Power quality maintenance support method and system in distribution system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain the power quality in a distribution system in which many distributed power sources are linked. <P>SOLUTION: A quality control center 1 delivers and receives the information to and from a distribution and transformer station control system 3 and each customer via communication lines 41, 42. The quality control center 1 monitors the system state of the customers' power source operation data and distribution system on line. As a result, if a voltage control value is deviated, the quality control center 1 selects the corresponding system control device and the customer's distributed power source, cooperates them, calculates their control values, and transmits the control values to the customer (for example, A) and the distribution and transformer station control system 3. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a distribution system and a distributed power supply control / operation method for maintaining power supply reliability and power quality in a distribution system in which a plurality of distributed power sources are interconnected.
[0002]
[Prior art]
In the domestic electric power business, deregulation of the “expansion of retail liberalization” is being considered. In March 2000, retail liberalization for large-scale customers was expanded. In 2005, application to high-voltage customers was expanded. Is scheduled to be fully liberalized for low-voltage consumers such as ordinary households. Along with this, it is expected that new retailers such as PPS (Power Producer and Supplier) will increase. On the other hand, from the viewpoint of effective use of natural energy, it is considered that the installed capacity of the distributed power supply is significantly increased.
[0003]
When these become reality, a large number of distributed power sources will be connected to the distribution system.For example, reverse power flow to the distribution system and an increase in short-circuit current will become apparent, and power quality and supply reliability will decrease. There is concern. In particular, maintaining an appropriate voltage is an important issue.
[0004]
Conventionally, there are few distributed power supplies connected to a distribution line, and the voltage tends to decrease toward the end of the distribution line. Therefore, as described in Electric Cooperative Research Vol. 56, No. 4, the delivery voltage of the distribution substation (transformer secondary bus voltage) is adjusted according to the magnitude of the load current of the distribution line. , Compensate for voltage drop. In particular, when the influence of the voltage drop is large, the voltage drop is compensated by using a line voltage regulator installed in the middle of the distribution line. Further, measures such as changing the system configuration by switching the section switches to eliminate the tidal current neck may be taken. As described above, basically all measures are taken on the distribution system side.
[0005]
In a system in which a large number of distributed power supplies are connected, a voltage rise due to reverse power flow of the power supply becomes a problem. At present, according to the grid interconnection guidelines, it is obligatory for the distributed power supply connected to the grid to have a function (power factor adjustment, output limitation) for suppressing a voltage rise in the power supply control device. In this case, depending on the installation position and the conditions of the distribution lines connected to the system, the output of only the power source owned by a specific customer may be limited at all times, and unfairness such as the merit of installing the power source cannot be obtained. There is a possibility.
[0006]
Therefore, an electric power supplier installs distributed power sources such as solar cells, fuel cells, and micro gas turbines in users such as ordinary homes, apartment houses, and small business establishments. There is a description in Patent Document 1 concerning a system for supplying. Here, in order to prevent the above-mentioned unfairness from occurring in the voltage rise suppression function, an upper limit value capable of reverse power flow is determined and operated for each customer.
[0007]
[Patent Document 1]
JP-A-2002-152976 (paragraphs 0032-0041, FIG. 1)
[0008]
[Problems to be solved by the invention]
When a large number of distributed power sources are interconnected and output a reverse power flow to the distribution system, the distribution of voltage on the distribution line changes from a monotonous drop to a very complicated distribution, such as an increase in voltage on the way. Therefore, it may not be possible to cope with the above-described complicated voltage distribution compensation only by the combination of the delivery voltage control and the line voltage regulator in the conventional distribution substation.
[0009]
In addition, in the method of improving the voltage distribution by eliminating the power flow neck of the distribution line using the section switch, it is considered that it is necessary to frequently change the system configuration. Inability to withstand frequent operations. To solve these problems, there is a method to increase the number of distribution lines, but it is not a practical measure because the economic burden on the grid operator is large.
[0010]
It is also conceivable that the electric power company, as a system administrator, may tighten the system interconnection conditions for distributed power sources, oblige consumers to install voltage compensators, and impose restrictions on reverse power flow and connection to small-scale power sources. . However, these are factors that hinder the spread of distributed power generation, and are not completely acceptable given the social trend of effective energy use for environmental protection.
[0011]
On the other hand, in Patent Document 1, in order to eliminate the unfairness of the start time of the output limitation by the voltage rise suppression function, the interconnection point voltage is maintained within an appropriate range for the power supply connected to the same pole transformer. A method has been proposed in which the upper limit of the reverse power flow is determined so that the power can be transmitted to each power supply. However, in the method of setting the output limit value for each power supply, if the secondary side of the pole transformer is set near 107 V, which is the upper limit value of the voltage management range, all the power supplies end up with reverse power flow. This can lead to inequality that it will not be possible. Actually, in order to suppress the voltage rise, it is necessary to consider the use of the reactive power control of the power supply and the coordination with the voltage control of the interconnection point with the high-voltage distribution line. However, in this example, the control target is only the distributed power supply of the customer (and only the low-voltage power supply), and the cooperative control with the system control device installed in the distribution line is not handled. The exchange of information with the electric power company is also one-way, and is performed only when the output of the power supply is increased upon receiving a request from the electric power company when power is tight. Thus, it cannot be said that sufficient consideration has been given to maintaining the power quality.
[0012]
An object of the present invention is to provide a power quality maintenance support method and system by flexible interconnection of a power distribution system and a distributed power supply in view of the above-described problems of the related art.
[0013]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, in the present invention, a quality control center is installed, a power supply operation data of a customer and a system state of a distribution system are obtained online, and a power quality maintenance device installed in a distributed power supply and a distribution system. Are coordinated to calculate the respective control values, so that the output command of the distributed power supply is transmitted to the customer and the control command of the quality maintenance device is transmitted to the system administrator.
[0014]
The present inventors have applied for Japanese Patent Application No. 2002-159565 in connection with the above problem. The outline of this earlier application is as follows. Based on contracts between the power information service provider and the contractor A (a company that owns the regional transmission and distribution system) and the contractor B (a customer with a distributed power source), the power information at the distribution substation and each customer Own collection means and collect information. Based on the collected information, the supply capacity and the power shortage are compared between the generators in the system, and the output of the distributed power source is set, and the center applies for an increase in the output of the distributed power source. When an application is made, information on the operation status of the local grid, such as voltage and section current, is collected, and based on these information, a simulation of the power flow and voltage distribution in the local transmission and distribution system is performed. It determines whether it is possible, and if possible, gives an instruction to the voltage regulator and an instruction to the distributed power supply.
[0015]
In other words, the prior application is an invention in which, if a power quality problem occurs during power transfer, the problem can be resolved as much as possible to enable the transfer. Specifically, when there is a problem with the voltage and power flow at the time of application for consignment, it waits for a certain period of time, and if it is still not improved, the consignment, that is, the output change of the distributed power supply is forgotten, and means for improving power quality are installed in the system There is only a voltage regulator.
[0016]
On the other hand, the present invention is an extension of the above-mentioned prior application invention. The purpose of the present invention is to maintain power quality not only at the time of changing the output of a power supply by consignment, but also at the time of a system (load) state that is constantly changing in an operating state. In order to realize this, not only the equipment on the grid side but also the cooperation of the customers (reactive power control of the distributed power supply and control of the power factor adjustment device) are requested, and the output restriction is not imposed on the distributed power supply as much as possible. Is to do so. Therefore, it is possible to cope with a large-scale connection or a centralized connection of an unstable distributed power supply (for example, a power supply using natural energy such as solar power generation) which causes a large load fluctuation at all times.
[0017]
Although the prior invention does not show a method for controlling the voltage regulator installed in the system as a specific measure against the voltage problem, the present invention presents the control method in detail.
[0018]
Further, in the prior application, the customer to be contracted, that is, controlled, is only the user (contractor B) holding the distributed power supply. However, in the present invention, in order to have the customer cooperate thinly and widely in order to maintain the power quality and to increase the degree of freedom of control, consumers who do not have a distributed power supply but have a power factor adjusting device are also controlled. . In addition, it has a concept that is not seen in previous applications, in which consumers are encouraged to contribute to the improvement of voltage problems and the like and pay for it.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Prior to the description of the embodiments of the present invention, a basic framework of a power quality maintenance support system for a distribution system to which the present invention is applied will be described.
[0020]
FIG. 3 is a business conceptual diagram showing a basic framework of the present invention. Establish a quality management and supply and demand coordination agency, which concludes equipment monitoring and operation contracts with the customer group, provides customers with distributed power supply operation and equipment abnormality monitoring services, and provides contract fees and control. Get the information you need. Here, the contract includes cooperation for maintaining power quality. On the other hand, a quality management agency contract is concluded with the electric power company, the system status necessary for control calculation is obtained under a predetermined contract fee, and the power quality of the system is monitored. When a problem occurs in maintaining the power quality, a control command to the system control device and the distributed power source is sent to a power company or a customer to try to solve the problem.
[0021]
Next, an embodiment of the present invention will be described. FIG. 1 is a single-line diagram showing the configuration of the power quality maintenance support system of the present invention. The present invention mainly relates to a quality management center 1 owned by a quality management agency, a distribution substation 2 owned by a power company, distribution lines and system control devices, and consumers A to C receiving power supply from the distribution lines. The transfer of information related to is shown. The distribution substation control system 3 sends a control command to the distribution substation 2 to operate the distribution system. Note that FIG. 1 shows only the customers A to C for simplicity, but it is assumed that more customers actually exist. In addition, the system control device describes the minimum position required for explanation.
[0022]
In this example, the distribution substation 2 includes two banks of transformers for a substation, and two sets of distribution lines are laid on the transformers of each bank, respectively, and the distribution lines 2A1 and 2A2 of the bank 2A are provided. A switch 2A11 with a sensor and a line voltage regulator 2A12 are provided. The same applies to the other banks 2B. Interconnection devices 51 to 53 for interconnecting the distribution lines with each other are installed between the distribution lines. The interconnecting devices 51 to 53 may be operated in an always “open” state, or may be operated in an always “closed” state.
[0023]
Each customer is connected to a distribution line via a power receiving transformer 12 and a circuit breaker 11, respectively. For transmitting the output of the distributed power supply 9 and the measurement result of the information of the load 8 to the quality management center 1 via the communication line 42, and for controlling the distributed power supply and the load based on a control command from the quality management center. A communication control device 7 is provided.
[0024]
The customer A is a relatively large-scale customer who receives power under high-voltage interconnection conditions and has a distributed power source, and the customer B is a customer who receives power under high-voltage interconnection conditions and does not have a distributed power source, and customers C1 to Cn. Is assumed to be a customer who receives power under low-voltage interconnection conditions and owns a small distributed power source. Examples of the customer A include customers having an important load, such as a process factory, an intelligent building, and a hospital. Examples of the customer B include a production factory and an office building having no significant load. As an example of the customer C, a general household, a small office, a combination, or the like has a distributed power supply such as a photovoltaic power generator, a fuel cell, and a micro gas turbine.
[0025]
The quality control center 1 exchanges information with the distribution substation control system 3 and each customer via the communication lines 41 and 42. Therefore, the communication control apparatus 101 includes a communication server 101, an arithmetic server 102 for performing power quality maintenance support processing, and a storage device 103 for storing data and arithmetic results required for arithmetic processing as necessary. The arithmetic server 102 monitors the voltage distribution, the power distribution, and the like based on the distributed power supply data measured by the communication control device 7 installed in each customer and the system status data obtained from the distribution substation control system 3. I do. When deviating from the voltage management value, the control values of the system control device and the distributed power supply are calculated.
[0026]
FIG. 2 is a configuration example of an interconnecting device installed at an interconnecting point of a distribution line in a normally “closed” state. These are devices for connecting two sets of distribution lines to each other to form a loop, and can control active power (power flow) and reactive power in the loop. It has the role of eliminating the imbalance of the substation sending current due to the imbalance of the load on each distribution line, and maintaining the voltage in an appropriate range by reactive power control.
[0027]
FIG. 1A shows a configuration in which a phase adjuster using a power converter and a switch are combined. 501 is a power converter, 502 is an adjusting transformer connected in parallel with the distribution line to supply power to the power converter 501, 503 is a series transformer for applying the output voltage of the power converter 501 to the distribution line, 504 is a control device of the power converter 501. Reference numeral 506 denotes a switch for bypassing the power converter 501, the control device 504, the adjustment transformer 502, and the series transformer 503 when an abnormality or a failure occurs. Reference numeral 505 denotes a switch for disconnecting a connection point of a distribution line.
[0028]
Since this interconnection device can control the active power and the reactive power passing through the interconnection point, it is effective for voltage control and power flow distribution control. In the present device configuration, the device capacity depends on the active power and the reactive power to be adjusted, so that the device capacity can be realized with a relatively small capacity, and the cost and the conduction loss can be reduced.
[0029]
FIG. 2B shows an example in which the concept of DC interconnection is applied, wherein 508 is a power converter, 507 is its control device, and 509 is a switch for disconnecting the interconnection point of the distribution line.
[0030]
This interconnection device generally has a large capacity because the device capacity is determined by the passing power at the interconnection point of the installed distribution line. Therefore, the cost and conduction loss are high, but since they are converted to direct current and then connected, the effect of preventing an accident that occurred on one distribution line from spreading to the other distribution line and suppressing the short-circuit current Can be expected to be effective.
[0031]
In the present invention, the configuration of the interconnection device is not limited to any of FIGS. 2A and 2B. In addition, when it is always “open”, a normal sectional switch can be used as the interconnection device.
[0032]
FIG. 4 shows the procedure of an embodiment of the power quality maintenance support method according to the present invention. The quality management agency enters into a quality management agency contract with the power company. The power company pays the quality management agency fee to the quality management agency company and provides the system status data. The quality control agency monitors the power quality based on the system status data.
[0033]
On the other hand, the quality management agency concludes a power supply operation contract with each customer who has a distributed power supply. If the customer has selected the option of electric power supplier as an option, the quality control agency presents the electric power supplier to the customer, and the customer contracts with the indicated electric power company and based on the electricity supply agreement. Buy power and pay for electricity. The quality management agency company operates the power supply equipment on the basis of the power supply state data provided by the customer, and obtains an operation agency fee from the customer.
[0034]
When the power quality of the power system is degraded, the quality management agency sends a control command to the grid control device to maintain the quality, and also sends a power output adjustment command to the customer. The quality management agency company pays the customer a quality management cooperation fee for the reduced cost merit due to the adjustment of the output of the power supply, or for the number of cooperation and the amount of cooperation (reactive power integrated value).
[0035]
FIG. 5 shows an example of a customer who does not have a distributed power source as a specific procedure of the power quality maintenance support method. The relationship between the quality management agency and the power company is exactly the same as in the example of FIG. On the other hand, the quality management agency enters into a power receiving equipment monitoring contract with each customer who does not have a distributed power source. If the customer has selected the option of electric power supplier as an option, the quality control agency presents the electric power supplier to the customer, and the customer contracts with the indicated electric power company and based on the electricity supply agreement. Buy power and pay for electricity. The quality control agency monitors the power receiving equipment of the customer, and if there is any abnormality, transmits the fact to the customer and obtains a monitoring fee from the customer.
[0036]
When the power quality of the power system deteriorates, the quality management agency sends a control command to the grid control device to maintain the quality, and also sends a power receiving equipment adjustment command (for example, a change in the setting of the power factor improvement device) to the customer. . The quality control agency pays the quality control cooperation fee to the customer for the equipment adjustment performed for the quality maintenance cooperation.
[0037]
FIG. 6 shows a procedure when a power distribution company that performs power supply and grid management in a specific area applies the power quality maintenance support method. This example is an example in which the functions of the quality management agent company and the electric power company shown in FIGS. 4 and 5 is only the business form, and the relationship with each customer is the same as in the examples of FIGS. Also, the control and operation are the same as in the case where the quality agency and the power company are separated as shown in FIGS.
[0038]
FIG. 7 shows an example of the type of contract concluded between the quality management agency and the customer. In this example, the contents of the agency service are a power supply operation agency, equipment abnormality monitoring, quality management cooperation, and a power supplier selection agency, and options are set in the contract by a combination of these. Options 1 to 3 are contract types for consumers who have distributed power sources, and options 4 and 5 are contract types for consumers who do not have distributed power sources.
[0039]
Next, a processing procedure in the quality management center 1 in the power quality maintenance support system of the present invention will be described. FIG. 8 shows a processing flow in the quality management center. The following processing is performed at predetermined time intervals, for example, at intervals of about 5 minutes to 10 minutes.
[0040]
First, data of voltage and current at a predetermined position of a distribution line is monitored as state data of the distribution system (S1). This collects the measurement data of the switch with sensor 2A11 and the pole transformer 14 and the like installed in the system via the distribution substation control system 3. The monitored system status data is stored in the system status DB 1031.
[0041]
Next, the output of the distributed power supply, power consumption data, and the like are collected via the communication control device 7 installed in the consumer (S2). The collected customer status is stored in the customer status DB 1033.
[0042]
Based on the system status data collected in S1, a location where the voltage deviates in each feeder of the distribution line is searched (S3). The voltage deviation point is determined by creating a voltage profile of each distribution line from the system information obtained at regular time intervals and the receiving end voltage of each customer, and comparing this with the appropriate voltage range to find the corresponding distribution line and its location. (Section) can be specified.
[0043]
Next, the amount of electric power supplied by each distribution line is calculated, and the distribution of the power flow of each distribution line is calculated (S4).
[0044]
The distribution line voltage and power flow are evaluated using the calculation results of S3 and S4 (S5). That is, in each distribution line, the evaluation is made as to whether or not there is a voltage deviation point and whether the distribution of power flow is within an allowable range (distribution loss is within an allowable range, or whether or not there is an overload).
[0045]
As a result of the evaluation, if there is no problem, the processes of S11 to S14 are performed. If there is a problem, the processing of S6 to S10 is performed. Here, the processing of S11 to S14 corresponds to the arithmetic processing regarding the economical operation of the distributed power supply, and is the same as the method shown in FIGS. 6 and 7 of the prior application (Japanese Patent Application No. 2002-159565).
[0046]
If there is a problem in the evaluation result of S5, the system control device and the customer to be subjected to the power quality maintenance control are selected, and the control amount of the system control device and the customer's equipment (distributed power supply or power factor adjusting device) is selected. Is set (S6).
[0047]
For example, when a voltage deviation section is detected near the end of the distribution line 2A1, the target device is selected as follows. A case where there is no loop in which the interconnecting devices 51 to 53 shown in FIG. 1 are always operated in an “open” state will be described. The bank transformer 2A of the distribution substation to which the corresponding distribution line is connected, and the line voltage regulator 2A12 closest to the upstream side (including the section) of the section including the voltage deviation point are selected. Further, the customers A and C are selected as the customers in and around the corresponding section.
[0048]
The control amount of the device to be controlled is set according to the problem that has occurred. For example, if a deviation from the voltage upper limit occurs, the tap is lowered by one tap to the bank transformer 2A and the line voltage regulator 2A12, and the reactive power change amount of the distributed power supply (from the grid side) to the consumers A and C. Therefore, a power factor of 0.01 is set with a delay).
[0049]
Next, a case where there is a loop in which the interconnecting devices 51 to 53 shown in FIG. 1 are always operated in a “closed” state will be described. For example, the bank transformer 2A of the distribution substation to which the corresponding distribution line is connected and the interconnection device 52 installed near the section including the voltage deviation point of the corresponding distribution line 2A1 are selected. Further, the customers A and C are selected as the customers in and around the corresponding section. In some cases, the customer B is also a candidate for control. In this case, similarly to the case without the loop, the control amount of the device to be controlled is set according to the problem that has occurred.
[0050]
In addition to the system status data and customer status data monitored for confirmation, a system simulation (power flow calculation) is performed using the control initial values of each device set in S6, and the voltage distribution and power flow distribution of each distribution line are calculated. (S7).
[0051]
With respect to the voltage and power flow of each distribution line obtained as a simulation result, the same evaluation as in S5 is performed (S8). That is, in each distribution line, the evaluation is made as to whether or not there is a voltage deviation point and whether the distribution of power flow is within an allowable range (distribution loss is within an allowable range, or whether or not there is an overload). If there is no problem, the process proceeds to S9, and if the problem is not solved, the process returns to S6 to change the control amount of each device and perform the processes of S6 to S8 again.
[0052]
If there is no problem in S8, the control command value determined by the simulation is transmitted to the system control device to be controlled and the distributed power supply of the consumer via the communication control device 101 (S9).
[0053]
At the same time, the degree of contribution of the customer who has been subjected to the quality maintenance control is evaluated (S10), and the data is registered and updated in the data of the customer contribution DB 1034, and then the process proceeds to the next time step.
[0054]
For the quality management cooperation fee, for example, a contribution is paid for the degree of contribution by the reactive power control in a form such as x ￥ / number of times in accordance with the number of times of cooperation for quality maintenance. Alternatively, the amount of reactive power adjusted for quality maintenance is integrated and recorded, and a fee is paid in units of y / kVar in units of one month. In addition, for the contribution by the active power limitation of the distributed power source, for example, the power amount (kWh) of the active power limited for maintaining the quality is recorded, and the cost merit reduction (= limited effective power) is recorded. The amount of power (kWh) × the unit price of power sale ($ / kWh) is paid as a consideration.
[0055]
As a result of the evaluation in S5, if there is no problem, the output control command value of the distributed power supply 9 of each customer is calculated (S11). Using the prediction data such as weather and temperature acquired from the power generation characteristic database 1035 and the external database 1036, the power generation output amount is optimized so that the facility operation cost is minimized.
[0056]
A system simulation (power flow calculation) is performed using the system status data and the customer status data monitored in S1 and S2 and the output control command value of the power supply changed in S11, and the voltage and power flow distribution of each distribution line are calculated ( S12).
[0057]
With respect to the voltage and power flow of each distribution line obtained as a simulation result, the same evaluation as in S5 is performed (S13). For each distribution line, evaluate whether there is a voltage deviation point and whether the distribution of power flow is within the allowable range (distribution loss is within the allowable range, or whether there is an overload). If there is a problem, return to S11, change the output control command value of each distributed power supply, and perform the system simulation again.
[0058]
If there is no problem, the process proceeds to S14, and the output control command value determined by the simulation is transmitted to the distributed power supply of each customer via the communication control device 101.
[0059]
Next, the effect of the control operation for maintaining the power quality according to the present embodiment will be described. FIG. 9 shows a control operation example when a deviation from the voltage upper limit occurs. This is an example in which the deviation of the voltage upper limit value occurs in the distribution line 2A1 when there is no loop in which the interconnecting devices 51 to 53 illustrated in FIG. 1 are always operated in the “open” state. (A) is an example of voltage control by a distribution voltage substation, (b) is voltage control by a line voltage regulator, and (c) is voltage control by reactive power control of a distributed power supply.
[0060]
In the distribution line 2A1, when the distributed power sources owned by the customers A and Cn flow backward, the voltage rises as shown by the broken line in FIG. 9A and deviates from the appropriate range. At this time, the bank transformer 2A of the distribution substation to which the corresponding distribution line is connected is selected, and taps are switched so as to lower the sending voltage, thereby obtaining a voltage distribution as shown by the solid line in (a).
[0061]
Next, the line voltage regulator 2A12 which is closest to the upstream side (including the section) of the section including the voltage deviation point is selected, and the tap is switched so as to lower the voltage, and the tap is switched as shown by the solid line in (b). Obtain the voltage distribution. Furthermore, for sections that do not fall within the proper range, the reactive power (delayed from the viewpoint of the system) is supplied from the distributed power sources owned by the customers A and Cn, and the voltage is further reduced to keep the voltage within the proper range. it can.
[0062]
FIG. 10 shows the case where there is a loop in which the interconnecting devices 51 to 53 shown in FIG. 1 are always operated in the “closed” state, the distribution line 2A1 deviates from the upper voltage limit, and the distribution line 2A2 is caused by heavy load. It is a control operation example when the deviation of the voltage lower limit occurs. (A) is the control of the delivery voltage of the distribution substation, (b) is the voltage control by the active / reactive power control of the interconnection device, and (c) is the voltage adjustment by the reactive power control of the distributed power supply.
[0063]
In the distribution line 2A1, the decentralized power sources owned by the customers A and Cn flow backward, the voltage rises as indicated by the broken line in (a), and the voltage of the customer B causes a significant voltage drop. Assume out of range. At this time, the bank transformer 2A of the distribution substation to which the corresponding distribution line is connected is selected, and taps are switched so as to lower the sending voltage, thereby obtaining a voltage distribution as shown by the solid line in (a).
[0064]
Next, the interconnection device 52 installed in the corresponding distribution lines 2A1, 2A2 is selected, the power flow distribution is adjusted by the active power control, and the voltage is brought close to an appropriate range by the reactive power control. At this point, the distribution line 2A2 was within the appropriate range. Further, for the section of the distribution line 2A1 which still does not fall within the proper range, the reactive power (delayed from the viewpoint of the system) is supplied from the distributed power source held by the customers A and Cn, and the voltage of the section is reduced to make the proper range. Can be kept within.
[0065]
In this way, by coordinating control of the system control equipment and the customer's distributed power supply equipment, even if a large amount of distributed power supply is introduced into the distribution system, capital investment such as additional distribution lines is required. The power quality of the power distribution system can be maintained in an appropriate state without using the power supply. In addition, in the present invention, since the customers themselves who are also users of the distributed power supply cooperate in maintaining the quality, the system interconnection conditions of the distributed power supply are strictly required, and the installation of the voltage compensating device in the customer is obliged, and the small power supply is required. There is no need to impose reverse power flow restrictions or connection restrictions. Therefore, the barrier for introducing the distributed power source can be reduced, and the restriction on the operation of the distributed power source can be reduced, so that the cost merit of the customer due to the introduction of the distributed power source can be secured.
[0066]
FIG. 11 shows a configuration example of a data file used by the management server of the quality management center. In the storage device 103 of the quality control center 1, there is a file of data 1031 that stores system status data such as voltage and current at a predetermined position of each monitored distribution line. In addition, the state of the system control equipment (operating state, control value, etc.) such as the switch with sensor 2A11 installed on each feeder, the line voltage compensator 2A12, the pole transformer 14, and the interconnection devices 51 to 53 of the distribution line. Etc.) are stored in the system control device data 1032 file. In addition, the customer status data 1033 storing data such as the monitored power supply output and load of each customer, the customer contribution degree data 1034 indicating cooperation of each customer for quality control, and the power generation characteristic data 1035 of each distributed power supply. There is a file. Further, it is composed of files of weather forecast data, wind condition forecast data, and temperature forecast data that are sequentially obtained, organized, and stored from an external database via a communication line.
[0067]
FIG. 12 shows an example of an output screen of the management server of the power quality maintenance support system. As the distribution system status display, the voltage, current value, presence / absence of voltage deviation, load factor, presence / absence of system failure, and the like of each unit monitored for each distribution line are displayed. In addition, as the customer status display, the content of the power reception contract, the type of power source held, and the monitored power generation output are displayed for each customer. Further, the cost merit (%) relative to the cost (power rate) when all the power is covered by the purchased power, the number of times of cooperation for power quality maintenance control (times), the presence / absence of a customer facility abnormality, and the like are displayed.
[0068]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the power quality of a distribution system can be maintained in an appropriate state by controlling a grid control apparatus and a customer facility (distributed power supply or a power factor adjustment apparatus) cooperatively.
[0069]
As a power company, the distributed power sources and power factor adjustment devices owned by customers can play a part in maintaining power quality, so even if many distributed power sources are interconnected, maintain power quality such as adding distribution lines. Can reduce capital investment.
[0070]
In addition, there is no need to tighten the grid connection conditions of the distributed power supply more than necessary, which reduces the barriers for consumers to introduce the distributed power supply and reduces the restrictions on the operation of the power supply. Can be prevented from decreasing. Therefore, it is possible to eliminate a factor inhibiting the spread of the distributed power supply.
[Brief description of the drawings]
FIG. 1 is a single-line diagram showing a configuration of a power quality maintenance support system according to an embodiment of the present invention.
FIG. 2 is a block diagram of an interconnection device installed at an interconnection point of a distribution line.
FIG. 3 is a conceptual diagram showing a basic form of business according to the power quality maintenance support method of the present invention.
FIG. 4 is a flowchart showing an example of a business according to the power quality maintenance support method of the present invention.
FIG. 5 is a flowchart showing another example of business according to the power quality maintenance support method of the present invention.
FIG. 6 is a flowchart showing still another example of business by the power quality maintenance support method of the present invention.
FIG. 7 is an explanatory diagram showing an example of a contract type between a quality management agent company and a customer.
FIG. 8 is a flowchart illustrating a procedure of a power quality maintenance support method according to an embodiment of the present invention.
FIG. 9 is a voltage transition diagram showing the effect of the control operation of the power quality maintenance support system.
FIG. 10 is a voltage transition diagram showing the effect of another control operation of the power quality maintenance support system.
FIG. 11 is a configuration diagram of a data file used in the management server.
FIG. 12 is a screen configuration diagram illustrating an example of a display screen of the management server.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Quality management center, 101 ... Communication control device, 102 ... Management server, 103 ... Storage device, 2 ... Distribution substation, 2A, 2B ... Bank transformer, 2A1, 2A2, 2B1, B2 ... Distribution line, 2A3, 2A4 , 2A5 ... distribution line interconnection, 2A11 ... switch with sensor, 2A12 ... line voltage regulator, 3 ... distribution substation control system, 41, 42 ... communication line, 51-53 ... interconnection device, 7 ... communication Control terminal, 8: load, 9: distributed power supply, 10: power factor adjusting device, 11, 13: breaker, 12: power receiving transformer, 14: pole transformer.

Claims (8)

Obtain the operation data of the distributed power supply of the customer and the system state data of the distribution system online, calculate the respective control values by coordinating the distributed power supply and the system control equipment installed in the distribution system, and calculate the distributed type. A power quality maintenance support method for a distribution system, comprising transmitting a power supply output control command to a customer and a control command of the system control device to a distribution substation control system. System status data of the distribution system, operating data and load data of a customer having a distributed power source, and obtaining load data of a customer having a power factor adjusting device online, the system status data, the operating data and the Based on the load data, the system control equipment installed in the distribution system and the distributed power supply or power factor adjustment device, which are the facilities of the customer, are coordinated to calculate respective control values, and output control of the distributed power supply A power quality maintenance support method for a distribution system, comprising: transmitting a command and an adjustment command of the power factor adjusting device to a customer; and transmitting a control command of the system control device to a distribution substation control system. In claim 1 or 2,
If there is an abnormality in the distribution line where the voltage and / or power flow deviates from the appropriate range from the obtained system state data, a system control device and a customer that can contribute to the elimination of the abnormality are selected, and the abnormality of the distribution line is eliminated. A power quality maintenance support method for a power distribution system, wherein In claim 3,
The control value for eliminating the abnormality of the distribution line, the output voltage to the distribution line and the adjustment amount of the line voltage regulator on the system side, the reactive power amount of the distributed power supply on the customer side, To maintain the power quality of the distribution system. In a power quality maintenance support system including a quality control center that monitors the power quality of a distribution system that connects a plurality of customer facilities having a distributed power source, the quality management center transmits online the operation data of the distributed power source of the customer. Means for obtaining system status data of the distribution system online, means for calculating the respective control values by coordinating the distributed power supply and system control equipment installed in the distribution system, and distributed power supply. A means for transmitting a power control command to a customer and a control command for a system control device to a distribution substation control system. In a support method for a proxy company to connect a power company and a customer through a network, monitor the power quality of the distribution system, and maintain the quality,
The agency acquires online the system status data of the distribution system from the power company and the operation data of the distributed power supply from the customer, and when the distribution system has an abnormality in which the voltage and / or power flow deviates from the appropriate range, It is characterized in that a system control device related to the abnormality and a distributed power source of the customer are selected, and a system control device control command is sent to the power company and a power output adjustment command is sent to the customer online so as to eliminate the abnormality. Power quality maintenance support method for distribution system. In claim 6,
The agency company concludes a power supply operation contract for the distributed power supply with a customer in advance, and performs remote operation of the distributed power supply and outputs a power output adjustment command in the event of the abnormality, thereby maintaining power quality of the distribution system. How to help. In claim 7,
A power quality maintenance support method for a distribution system, wherein the agency company measures the number or degree of customer cooperation with the power supply output adjustment command and calculates a quality management cooperation fee.

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