JP2010233353A - Power supply system and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply system that stabilizes a voltage state in a power system by controlling a battery device provided on the power system side. <P>SOLUTION: The power supply system includes a plurality of battery devices connected to the power system, a detection unit detecting a system frequency and a system state in an area, and a first control unit controlling a plurality of battery devices based on the system state detected by the detection unit according to the control order of the battery devices connected to the power system, which is determined on the basis of a predetermined parameter relating to the efficiency of power transmission between the plurality of battery devices and the power system. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a power supply system capable of controlling the amount of power supplied to a load by providing a power storage device on the power system side.

  In order to realize a low-carbon society in consideration of the global environment, it has been studied that a large amount of renewable energy using solar power generation or the like is introduced into a conventional power system. Here, since the output (power generation amount) of such renewable energy fluctuates from moment to moment according to natural conditions such as the weather, the more renewable energy is used in the electric power system, There is a high possibility of causing voltage fluctuations and frequency fluctuations. For this reason, if a large amount of renewable energy is introduced, and the amount of power generated cannot be controlled appropriately according to the power flow situation and frequency situation of the power system, the voltage quality in the power system will be degraded.

  In view of such a problem, in order to stabilize and level the power flowing through the power system even if the amount of renewable energy introduced into the power system increases, the power storage device on the consumer side where the load exists And a technique for controlling the amount of stored electricity online from the power system side is disclosed (see, for example, Patent Documents 1 to 3). In these technologies, efficient voltage control is attempted by centrally controlling power storage devices provided on the individual customer side from the power system side.

JP 2006-94648 A JP 2008-67469 A JP 2001-37085 A

  In consideration of the fact that the electric power supply from the power grid to the load in the supply area is basically an energy that cannot be stored, the supply amount is changed every moment according to the demand amount by the load. There is a need. This is because if the demand amount and the supply amount are unbalanced, the quality of the power is reduced due to the fluctuation of the frequency. In addition, due to the recent increase in environmental awareness, distributed generators that can supply power to the load independently of the power supply from the power system, such as dispersion that converts natural energy such as sunlight and wind power into power The spread of type generators is required. As a result, the amount of power to be supplied from the power system can be reduced, and the environmental load generated during power generation in the power system can be kept low. If it becomes large, it may become a factor that causes an imbalance in the balance with the power supplied from the main power generation device (thermal power plant, nuclear power plant, etc.) of the power system. In order to cope with the fluctuations in the power generated by the distributed power generator described above, it is conceivable to introduce a large amount of power storage devices at a substation or the like and to perform control such as absorbing surplus power by the distributed power generator. There is a problem of how to operate and control the storage battery introduced in large quantities.

On the other hand, system abnormalities in the power system include phenomena such as overload of power transmission equipment such as transmission lines and transformers, and overvoltage and voltage drop due to excessive rise and fall of the system voltage. In order to deal with these system abnormalities, output control of the generator and phase control equipment such as a power capacitor and a reactor are controlled. Regarding the output control of the generator in this case, a technique for controlling the power storage devices distributed in the power system and introduced in large quantities as the generator to be controlled has not been disclosed yet.

  The present invention has been made in view of the above problems, and by providing a plurality of power storage devices in the power system and controlling it, the frequency of the power system can be stabilized, the voltage can be maintained, or the power transmission facility can be prevented from being overloaded. An object is to provide a stable power supply system.

  In order to solve the above problems, in the power supply system according to the present invention, a plurality of power storage devices connected to the power system are provided, and power transfer between the power storage device and the power system is determined by a predetermined parameter. The control is performed according to the control order of the power storage devices. As a result, the power storage device necessary for stabilizing the state of the power system can be appropriately controlled, and thus the quality of the power system can be kept good.

  Specifically, the present invention is a power supply system that supplies power from a power system having a main power supply source to a load in an area to be supplied with power, and is connected to the power system, Control power supply to the load via the power system or storage of power from the power system by temporarily storing power flowing through the power system or discharging the stored power to the power system. A plurality of possible power storage devices, a detection unit that detects an overload status of a power transmission facility, a voltage status, and a frequency of the power system, which is a system state in the area, and each of the power storage devices In accordance with a control order of power storage devices connected to the power system, determined based on a predetermined parameter related to power transmission efficiency with the power system, the complex based on the system state detected by the detection unit. Comprising a first control unit for controlling the base of the power storage device.

  In the power supply system according to the present invention, power from a main power supply source of a power system such as a thermal power plant or a nuclear power plant is supplied to a load that consumes power such as a home or a company office. The Here, the frequency of the power system is generally required to be within a predetermined range by controlling the power supply amount according to the power consumption amount in order to maintain the voltage quality to be supplied satisfactorily. It is done. Therefore, in the power system constituting the power supply system, a power storage device capable of storing and discharging is installed on the way from the power supply source to the load. As a result, on the power system side, in other words, in the process until power is supplied to the load, power storage through the power system or discharge to the power system is possible, and storage or discharge from the power storage device is possible. In addition, the output control of the main power supply source such as a thermal power plant is combined to maintain the frequency of the power system in an appropriate state.

  However, in order to properly maintain the frequency of the power system, power transfer between the power system and the power storage device must be accurately controlled. Conversely, excessive power storage or discharge is performed by the power storage device. Otherwise, the voltage state of the power system may be worsened. In view of this, the power supply system employs a configuration in which the control related to power transfer performed between the power system and the power storage device is performed by the first control unit.

The first control unit controls the plurality of power storage devices in accordance with the control order of the plurality of power storage devices installed, that is, the order regarding which power storage device is preferentially charged or discharged. This control order is a factor determined based on a predetermined parameter related to the power transmission efficiency between the power storage device and the power system, and may be determined in advance, and various electrical conditions in the power system It may be changed at any time according to. In this way, the control order is determined based on the predetermined parameter because the electric loss generated at the time of appropriately controlling the voltage state of the power system is suppressed as much as possible, and thus economical. This is to produce merit and environmental merit. The first control unit determines how much power should be exchanged between the power storage device and the power system based on the frequency state detected by the detection unit, and follows the above control order. The electric power is exchanged, that is, charging and discharging by the power storage device are realized while suppressing electrical loss. This stabilizes the frequency of the power system.

  Regarding the control order, the first control unit determines a control order of the power storage device based on a power transmission loss state between the power storage device and the power system or a power storage efficiency of the power storage device. The power storage device may be controlled in accordance with the determined control order. By using the control order determined in this way, the electrical loss can be suppressed.

  Here, in the power supply system, all areas to which the power system supplies power are divided into a plurality of subareas, and at least one subarea of the plurality of subareas includes the plurality of power storage devices. Consider a configuration in which two or more power storage devices are installed. In this case, when the voltage state in the one sub-area is an overvoltage or undervoltage state, or when the power transmission equipment in the one sub-area is in an overload state, the first control unit The two or more power storage devices may be controlled according to the control order of the two or more power storage devices installed in one subarea.

  That is, the entire area where power is supplied from the power system is divided into a plurality of subareas, and the first control unit determines the voltage state or the presence of equipment overload for each subarea, and then outputs the power storage device. By performing this control, it is possible to efficiently improve the voltage state of the sub-area and eliminate the overload of the power transmission equipment. In addition, a hierarchical area configuration may be adopted by dividing the sub-area into smaller areas. In such a case, the connection control by the first control unit may be performed for each hierarchy. .

  In the power supply system up to the above, in the area to be supplied with power by the power system, power is generated independently from the power supply source, and power is supplied to the loads in the area without going through the power system. There may be provided a plurality of distributed generators capable of reversely flowing part or all of the generated power to the power system. In this case, the power supply system shuts off the connection state of each of the plurality of distributed power generation devices to the power system and reversely flows from the power generation system to the power system. Is determined based on predetermined parameters relating to the reverse power flow from each of the plurality of distributed generators to the power system, based on the shut-off unit that disables the power supply and the system state detected by the detection unit And a second control unit for cutting off the connection between the plurality of distributed generators and the power system according to the cutoff order of the distributed generators cut off from the power system by the cutoff unit.

  For example, this distributed power generation device can generate power based on natural energy (for example, sunlight, wind power, etc.) at a place where it is installed. The amount of power supply can be reduced. In some cases, so-called power sale is performed in which the power that has not been consumed at the relevant point and is surplus is caused to flow backward to the power system, so that the power generated by the power system is collected. As a result, the distributed power generation apparatus may not only cover the power for its own use, but also may be paid for by selling power from the power system side. However, fluctuations in the output of the distributed power generator may adversely affect voltage increase in the area where the distributed power generator is installed or frequency fluctuations in the entire power system.

  Therefore, in the above power supply system, when the connection state between the distributed power generation device and the power system is canceled by the interrupting unit (in other words, when the disconnection state is formed), the distributed power generation device is connected to the power system. Reverse flow will not be possible. And the 2nd control part controls the propriety of the reverse power flow from this distributed generator to an electric power system according to the interception order of a distributed generator. This blocking order is determined based on a predetermined parameter regarding reverse power flow.

  Distributed power generators are usually connected to the power system for the convenience of users, and surplus power generated by the distributed power generator is connected to the power system so that reverse power flow is possible at any time. When the frequency state of the power generator rises beyond a certain range, or when the voltage state of the area where the distributed generator is installed is an overvoltage state, this reverse power flow is continued for the stabilization of the power system. Is not preferred. Thus, the frequency or voltage state of the power system is optimized by cutting off the distributed power generator and the power system by the second control unit. The reason why the interruption is performed in accordance with the interruption order is to realize the interruption based on the influence generated on the power system side by interrupting the reverse power flow. As a result, it is possible to improve the state of the power system while avoiding adverse effects on the power system as much as possible.

  The second control unit determines the cutoff order of the distributed power generation apparatus based on the power generation efficiency of the distributed power generation apparatus or the cost related to power generation by the distributed power generation apparatus, and the determined cutoff order The connection between the distributed generator and the power system may be controlled according to the following. Thereby, the bad influence to an electric power grid | system can be suppressed as much as possible.

  In the above power supply system, the entire area to which the power system supplies power is divided into a plurality of subareas, and at least one subarea of the plurality of distributed power generators Two or more distributed power generators may be installed. In this case, the second control unit is configured to transmit power when the voltage state in the one subarea is an overvoltage or in the one subarea. Is in an overload state, the cutoff of the two or more distributed generators and the power system is controlled according to the cutoff order of the two or more distributed generators in the one sub-area.

  It is also possible to grasp the present invention from the aspect of a method for supplying power to a load. That is, the present invention is a power supply source that is a main power system, and is connected to the power system and temporarily stores the power flowing through the power system or discharges the stored power to the power system. A load in an area to be supplied with power from the power system having a plurality of power storage devices capable of controlling power supply to the load via the power system or storage of power from the power system. A method of supplying power to the power supply system, the step of detecting the overload status of the power transmission equipment, the voltage status and the frequency of the power grid, which is the grid status in the area, and each of the plurality of power storage devices and the Determining the order of control for enabling power transfer between the power storage device and the power system based on a predetermined parameter relating to power transmission efficiency between the power system and the determined In accordance with the control order of collector, including a step of controlling said plurality of power storage device based on the detected strain state. As described above, also in the form of the power supply method, the system state of the power system can be favorably maintained.

  Further, based on the technical idea described above, the present invention can also be understood from the aspect of a control device for supplying power or a program for performing power supply control.

  By providing a power storage device on the power system side and controlling it, it is possible to provide a power supply system that stabilizes the system state of the power system.

1 is a schematic configuration diagram of a power system having a power supply system according to the present invention. It is a figure which shows the functional block of the electric power supply system which concerns on this invention. It is a flowchart of the 1st electric energy supply process for maintaining the system | strain state of this electric power system favorably performed in the electric power supply system shown in FIG. It is a list | wrist which shows the control order of an electrical storage apparatus at the time of the electric power supply process shown in FIG. It is a flowchart of the 1st electric energy supply process for maintaining the voltage state of this electric power system favorably performed in the electric power supply system shown in FIG. It is a list | wrist which shows the order | rank which interrupts | blocks a distributed generator from an electric power grid | system when the electric power supply process shown in FIG. 5 is performed.

  An embodiment of a power supply system according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows the electric power supplied from a thermal power plant 1 as a main power supply source through an electrical substation 2 to 4 in the middle (hereinafter referred to simply as “load”) such as a home or factory. The structure of the electric power system for supplying to (3) is shown in a simplified manner. In the illustrated power system, only the thermal power plant 1 is described as a power supply source, but a nuclear power plant or a hydro power plant may be included. The electric power from the thermal power plant 1 is first sent to the upstream substation 2 for distribution, and is then supplied to the loads 5 to 9 via the downstream substations 3 and 4.

  The upstream substation 2 is connected to the downstream substations 3 and 4 and the transmission line 11. Then, the transmission voltage from the downstream substation 3 is sent to the transformers 5a, 6a, and 7a via the power transmission line 12, respectively, and after being converted to 105V, is supplied to the loads 5, 6, and 7, respectively. Here, the load 5 is provided with a wind power generator 5b as a distributed power generator to assist in driving the load. The wind power generation device 5b is controlled in power generation by the control device and supplies the generated power to the power consumption at the load 5, thereby suppressing the amount of power supplied from the power system starting from the nuclear power plant 1. It becomes possible. In some cases, the amount of power generated by the wind power generator 5b is greater than the amount of power consumed by the load 5, and surplus power is generated. In such a case, the generated power is efficiently used by generating a so-called reverse power flow in which surplus power is collected on the power system side. Moreover, in order to assist each load drive in the load 6 and the load 7, the solar power generation devices 6b and 7b are installed as a distributed power generation device. The solar power generation devices 6b and 7b are controlled by the control device, and the generated power is supplied to the power consumption at the loads 6 and 7, so that the solar power generation devices 6b and 7b are supplied from the power system in the same manner as the wind power generation device 5b. It is possible to suppress the amount of electric power generated, and in some cases, it is possible to reversely flow surplus power to the power system. These distributed generators are not fixedly connected to the electric power system, but the distributed electric generators and the electric power system are cut off depending on the situation so that reverse power flow is impossible. The details will be described later.

  Further, the transmission voltage from the downstream substation 4 is sent to the transformer 8a via the power transmission line 13 and converted there to 105V, and then supplied to the loads 8 and 9. And about the load 8, in order to assist the load drive, the solar power generation device 8b is installed as a distributed power generation device. The solar power generation device 8b is also controlled by the control device so that the surplus power generated can be reversely flowed to the power system side in the same manner as the solar power generation device 6b and the like. It can be controlled as impossible.

  As described above, in the power system shown in FIG. 1, all areas to which the power system supplies power are divided into a plurality of sub-areas starting from the downstream substation. In FIG. 1, the entire area is divided into two: a sub area A covered by the downstream substation 3 and a sub area B covered by the downstream substation 4. In this embodiment, the number of divisions into sub-areas is two in order to simplify the description. However, it may be divided into a larger number or may be divided hierarchically.

In the sub-areas formed in this way, there are downstream substations that have jurisdiction over them, and each downstream substation temporarily stores the power flowing through the power grid, and stores that power. A power storage device (secondary battery) capable of discharging the generated power to the power system is installed. That is, these power storage devices are installed on the way from the thermal power plant 1 to each load in the power system, and this installation form is referred to as “install on the power system side”. In addition, a plurality of power storage devices are connected to each downstream substation (power storage devices 3a to 3n are installed in the downstream substation 3, and power storage devices 4a to 4n are installed in the downstream substation 4). The connection form between each power storage device and the power system is not fixedly connected, but connection and disconnection are appropriately controlled. This point will be described later. Note that the power storage device is not limited to the “installed on the power system side” form, and may be installed in the same location as the distributed power generation device or the load.

  As described above, in the power system shown in FIG. 1, the power supply from the power system is suppressed as much as possible by installing the power generation devices that generate power based on natural energy in each load except the load 9. On the other hand, the surplus power can be efficiently used in the entire power system by the reverse power flow from each distributed power generator. On the other hand, from the viewpoint of power supply by the power system, the power generation of the thermal power plant 1, which is the main power source of the power system, is executed so as to keep an appropriate balance with the expected power consumption at each power consumption point. Is done. This is because if the relationship between the supplied power and the consumed power is in an unbalanced state, the frequency fluctuates and the quality of the power is reduced. In addition, when such power supply is performed, if surplus power generated by each distributed generator is reversely flowed to the power system, the voltage state of the power system exceeds the appropriate range. An overvoltage condition can occur. Even when the influence of the reverse power flow from the distributed power generator is small, the voltage state may be excessively low. Such an improper voltage state is undesirable because it reduces the quality of the supply voltage. Alternatively, when the loads 5, 6, and 7 are very heavy loads, or when the loads are very light and the generated power from the distributed generators 5b, 6b, and 7b is large, the transformer of the substation 3 or The power flowing through the transmission line 11 may exceed an allowable value and become overloaded. An overload of the power transmission equipment leads to deterioration of the equipment, and in the worst case, the equipment is destroyed, so it is necessary to eliminate it immediately.

  Therefore, in order to form an appropriate state of the power system, the control device 2a shown in FIG. 1 performs processing related to the power storage devices 3a, 4a, and the distributed power generation device 5b provided in each load. The processing by the control device 2a forms the power supply system according to the present invention. Although not shown in FIG. 1, the control device 2a is connected to a storage device control device provided in each downstream substation and a distributed power generation device control device provided in each load via a network. Connected, and it is possible to transmit and receive information and instructions necessary for the above processing. 2 shows a functional block diagram of functional units formed in the control device 2a for the above processing, and refers to the power supply system according to the present invention.

  The control device 2a includes a system state detection unit 20, a control area determination unit 21, a control amount determination unit 22, a control rank determination unit 23, and a cutoff rank determination unit as functional blocks for processing related to reverse power flow from each power consumption point. 24, a power storage device control unit 25, and a distributed power generation device control unit 26 are formed. These functional units are formed by a program executed by a CPU and a memory constituting the control device 2a. On the other hand, although not shown, a control unit for controlling power storage and discharge by the power storage device installed in each of the control devices of the downstream substations 3 and 4 is formed. Based on the past power demand results for each sub-area, the amount of power currently required is predicted, and storage or discharging by the power storage device is performed according to the predicted amount. As a result, even if the amount of power sent from the thermal power plant via the upstream substation 2 deviates from the amount of power currently required, the amount of deviation can be covered to some extent by the power storage device. . In addition, a control unit that controls supply of generated power generated by the distributed power generation device to the load, reverse power flow to the power system, and the like is formed in the control device of the distributed power generation device corresponding to each load. The control unit supplies the generated power according to the power demand from the load, and if surplus power is generated there, it reversely flows to the power system.

  Here, each function part formed in the control apparatus 2a is demonstrated. The system state detection unit 20 detects the frequency in the power system shown in FIG. 1 and detects the voltage state and the presence / absence of overload equipment in all areas where power is supplied. In this embodiment, the frequency of the entire power system is detected, and the voltage state and the presence / absence of overload equipment are detected for each of two sub-areas constituting the entire area. Specifically, whether the frequency of the power system is within a certain range, and whether the transmission voltage value of the downstream substation covering each subarea is below or above a predetermined appropriate range, each subarea Based on whether or not there is an overload facility, it is detected whether the system state is appropriate. In addition, the range of the frequency, transmission voltage, and equipment overload value for an appropriate system state is determined in advance in consideration of the load existing in the sub area, the equipment provided in the sub area, and the like. Next, the control area determination unit 21 determines which sub-area is out of an appropriate state and becomes a control target based on the detection result by the system state detection unit 20, and the control amount determination unit 22 Based on the detection result, the control amount is determined for how much power should be increased or decreased in the sub-area to be controlled. For example, when the frequency rises beyond a certain range, the target is the entire system, and it is necessary to suppress power supply by the thermal power plant 1, the distributed power generation device, and the storage battery until the frequency becomes an appropriate frequency. . In addition, when the target subarea is in an overvoltage state, the amount of discharge by the storage battery in the subarea or the storage of electricity is reduced until it becomes an appropriate voltage state, or the distributed generator in the subarea The control amount determination unit 22 determines the required power amount.

  Next, the control order determination unit 23 determines the control order of the power storage device for transferring power between the power storage device and the power system. Moreover, the interruption | blocking order | decision | rank order determination part 24 determines the order | rank to interrupt | block, when electrically disconnecting the distributed power generator installed in each load from an electric power grid | system. The term “shutoff” as used herein refers to electrically shutting off a distributed generator that is electrically connected to a normal power system and capable of reverse power flow so that reverse power flow cannot be performed. And according to the control order determined by the control order determination part 23, the electrical storage apparatus control part 25 implement | achieves transfer of electric power between the electrical storage apparatus used as the object, and an electric power grid | system. Also, the distributed power generator control unit 26 disconnects the target distributed power generator from the power system according to the shut-off order determined by the shut-off order determining unit 24, and reverse power flow from the distributed power generator occurs. Do not.

Here, the control of power supply in an appropriate system state executed by the power supply system formed by the control device 2a will be described in detail with reference to FIG. First, in S101,
Electric power is supplied based on electric power demand. Here, it is determined whether the power demand amount and the power supply amount in all areas are balanced, that is, whether the frequency of the power system is within a certain range. The determination here relates to the entire power system, and does not correspond to each sub-area. When the process of S101 ends, the process proceeds to S102.

  In S102, the system state detection unit 20 detects the current voltage state of each of the subarea A and the subarea B and the presence / absence of overload equipment. That is, in the sub-area A, the voltage and the power flow state in the sub-area A reflecting the power consumption by the loads 5 to 7 and the reverse power flow by the distributed generators 5b to 7b are detected. If there is, the voltage and power flow state in the sub-area B reflecting the power consumption by the loads 8, 9 and the reverse power flow by the distributed power generation device 8b are detected. Thereafter, in S103, the control area determination unit 21 determines which subarea has a voltage state deviating from an appropriate range based on the detection result in S102, or which subarea has overload equipment. Determine and determine the sub-area that must be controlled. In the present embodiment, the following description will proceed assuming that the sub-area A is determined as the area to be controlled in S103.

  In S104, the control amount determination unit 22 determines the control amount in the sub-area A to be controlled. For example, when it is detected in S102 that the sub-area A is in an overvoltage state, in order to set the overvoltage state to an appropriate voltage state, how much power of the power system supplied in the sub-area A is within the sub-area A It is calculated in S104 whether it is necessary to remove it from the list. Here, as the amount of power to be removed increases, the power storage device on the power system side installed corresponding to sub-area A needs to suppress or store a larger amount of discharge. When the process of S104 ends, the process proceeds to S105.

  In S105, the control order determination unit 23 uses which power storage device among the plurality of power storage devices on the power system side installed corresponding to the subarea A to be controlled to use the system state of the subarea A. Control priority is determined. At this time, this control order is determined based on at least a parameter relating to power transmission efficiency between the power storage device and the downstream substation 3 which is equipment on the power system side. For example, the control order is set such that the discharge output is preferentially increased for the power storage device having a low power transmission loss between the power storage device and the downstream substation. Further, the control order is set so that the higher the power storage efficiency as the characteristic of the power storage device itself, the more preferentially the power storage device is controlled. In this way, the control order is determined based on the parameters related to power transmission efficiency. In controlling the state of the power system corresponding to the sub-area A to be controlled, the electrical loss generated at that time is suppressed as much as possible. Because. In determining the control order, it is preferable to take into account the voltage state adjustment capability of the power storage device (that is, the margin that the power storage device can store and the amount that the power storage device can discharge) as a parameter other than power transmission efficiency.

  Here, FIG. 4 shows a list of control orders determined by the control order determination unit 23. In the list shown in FIG. 4, three power storage devices installed corresponding to subarea A (3a to 3c) and power storage devices installed corresponding to subarea B are provided for the sake of simplicity. Are set to two (4a, 4b), and the control order determination unit 23 determines the control order for these five power storage devices. The list also shows the amount that each power storage device can discharge and the amount that can be stored at this time, and this corresponds to the adjustment capability of each power storage device. In the present embodiment, the control order determination unit 23 determines that the power storage device and the power system should be connected with priority in the order of the power storage devices 3a, 4a, 4b, 3b, and 3c. Therefore, in the present embodiment in which it is determined that the subarea to be controlled in S103 is only subarea A, the power storage devices 3a, 3b, and 3c are connected to the power system in this order. When the process of S105 ends, the process proceeds to S106.

  In S106, the power storage device control process is performed based on the control amount determined in S104 according to the control order of the power storage device determined in S105. For example, when it is necessary to remove the power corresponding to the control amount “15” from the power system corresponding to subarea A when the voltage state of subarea A is an overvoltage state, power storage devices 3a and 3b And the power storage is executed by both power storage devices. If the voltage state of sub-area A is a low-voltage state, the power storage device is controlled so as to supply electricity to the power system corresponding to the sub-area, that is, to discharge from the power storage device. The execution of power storage and discharge by the power storage device is issued from the control device 2a to the control device of the power storage device provided in the downstream substation 3, and the control unit in the control device executes according to the instruction. . When the process of S106 ends, the process proceeds to S107, where it is determined whether or not the system state of the sub-area A that is the target of control is an appropriate state. If the determination is affirmative, the process ends. If the determination is negative, the processes after S104 are performed again.

  As described above, according to the processing shown in FIG. 3, the power state is suppressed as much as possible by following the control order, and the voltage state is efficiently controlled by controlling the voltage state for each sub-area. It becomes possible to control to.

FIG. 5 shows an example of processing that is more advanced than the processing shown in FIG. In the process illustrated in FIG. 5, in addition to the above-described power storage device connection process, the distributed power generation apparatus blocking process is performed. Therefore, in the process shown in FIG. 5, the same reference numerals are assigned to the same parts as those in the process shown in FIG. 3, and detailed description thereof is omitted. In the process shown in FIG. 5, if a negative determination is made in S107, the process proceeds to S201. In S201, it is determined whether or not the voltage state of the sub-area A determined to be not a normal voltage state in S107 is an overvoltage state, and whether or not there is an overload facility in the area A. If an affirmative determination is made here, the process proceeds to S202, and if a negative determination is made, the processes after S104 are performed again.

  In S202, the shut-off order determination unit 24 uses which distributed generator among a plurality of distributed generators installed in the subarea A whose voltage state is to be controlled to use the grid state of the subarea A. In order to determine whether to control the power generation, the priority order of the disconnection between the distributed generator and the power system to be used is determined. At this time, the blocking order is determined based on at least a parameter relating to the reverse power flow of the power from the distributed generator. For example, the higher the power generation efficiency of a distributed generator, the greater the effect of reducing reverse power flow by cutting off the connection to the power system. Is set. In addition, if the load is cut off so that reverse power flow cannot be performed, the opportunity for selling electricity is lost. Therefore, there are cases where the power system side that supplies power has to pay compensation in order to compensate for the loss of the power selling opportunity. In such a case, the payment amount of the compensation can be suppressed by setting the order of shutting down the distributed power generation apparatus in which the compensation is set low to the order of being shut off preferentially.

  The blocking order determined by the blocking order determination unit 24 in this way is shown as a list in FIG. In addition, the interruption | blocking order | rank determination part 24 has determined the interruption | blocking order | rank with respect to the four distributed power generators installed in the subarea A and the subarea B. The list also shows the amount of reverse power flow that is the amount of power that each distributed power generation device is currently generating, that is, the amount of power that can be reduced by “cutting off”. In the present embodiment, the cutoff order determination unit 24 determines that the distributed power generators should be shut off from the power system with priority in the order of the distributed power generators 5b, 6b, 7b, and 8b. Therefore, in the present embodiment in which the subarea to be controlled is determined to be only the subarea A in S103, the power generation system is cut off in the order of the distributed power generators 5b, 6b, and 7b. When the process of S202 ends, the process proceeds to S203.

  In S203, according to the control sequence determined in S104, the process of electrically disconnecting the distributed power generator from the power system is performed according to the disconnection order of the distributed power generator determined in S202. For example, when the voltage state of the sub-area A is an overvoltage state and the power corresponding to the control amount “5” needs to be removed from the power system corresponding to the sub-area A, only the distributed power generation device 5b according to the cutoff order. Is disconnected from the power system. Unlike the power storage device, the distributed power generation device cannot store power from the power system. Therefore, when the voltage state of the sub-area A is a low voltage state (when a negative determination is made in S201), FIG. As in the process shown in FIG. 4, the processes after S104 are repeated.

  As described above, according to the process shown in FIG. 5, in addition to the process shown in FIG. It becomes possible to return the state to an appropriate state more quickly.

DESCRIPTION OF SYMBOLS 1 Thermal power plant 2 Upstream substation 2a Control device 3 Downstream substation 3a, 3b, 3c, 4a, 4b Power storage device 5-9 Load 5b Wind power generator (distributed power generator)
6b, 7b, 8b Solar power generator (distributed power generator)

Claims (7)

A power supply system that supplies power from a power system having a main power supply source to a load in an area to be supplied with power,
Power supply to the load via the power system or the power connected to the power system, temporarily storing power flowing through the power system, or discharging the stored power to the power system A plurality of power storage devices capable of controlling power storage from the grid;
A detection unit that detects a power transmission facility overload state, a voltage state, and a frequency of the power system, which is a system state in the area;
Detected by the detection unit according to a control order of power storage devices connected to the power system, determined based on a predetermined parameter related to power transmission efficiency between each of the plurality of power storage devices and the power system. A first control unit for controlling the plurality of power storage devices based on the system state,
A power supply system comprising: In the power supply system, all areas to which the power system supplies power are divided into a plurality of subareas, and at least one subarea of the plurality of subareas includes two of the plurality of power storage devices. More than one power storage device is installed,
When the voltage state in the one subarea is an overvoltage or undervoltage, or when the power transmission equipment in the one subarea is in an overload state, the first control unit Control the two or more power storage devices according to the control order of the two or more installed power storage devices,
The power supply system according to claim 1. The area to be supplied with power by the power system is capable of generating power independently from the power supply source and supplying power to the loads in the area without going through the power system, and generating the power A plurality of distributed power generators that can reversely flow part or all of the power to the power system side are provided,
The power supply system includes:
For the plurality of distributed power generators, shut off the connection state of each of the distributed power generators to the power system and disable reverse flow from the distributed power generator to the power system,
Determined from the power system by the shut-off unit, which is determined based on a predetermined parameter related to the reverse power flow from each of the plurality of distributed generators to the power system, according to the system state detected by the detection unit. A second control unit that cuts off the connection between the plurality of distributed generators and the power system according to the cutoff order of the distributed generators to be shut down;
The power supply system according to claim 1 or 2, further comprising: In the power supply system, the entire area where the power system supplies power is divided into a plurality of subareas, and at least one subarea of the plurality of subareas includes the plurality of distributed power generators. Two or more distributed generators are installed,
When the voltage state in the one subarea is an overvoltage, or when the power transmission equipment in the one subarea is in an overload state, the second control unit performs the second control section in the one subarea. Controlling the shutoff between the two or more distributed power generators and the power system in accordance with the shutoff order of the two or more power generators.
The power supply system according to claim 3. The first control unit determines a control order of the power storage device based on a power transmission loss state between the power storage device and the power system, or a power storage efficiency of the power storage device, and the determined control order Controlling the power storage device according to
The power supply system according to any one of claims 1 to 4. The second control unit determines a blocking order of the distributed power generation device based on power generation efficiency of the distributed power generation device or a cost related to power generation by the distributed power generation device, and the second control unit determines the blocking order according to the determined blocking order. Controlling the connection between the distributed generator and the power system;
The power supply system according to claim 3 or 4. A main power supply source of the power system, and the power system connected to the power system, temporarily storing the power flowing through the power system, or discharging the stored power to the power system, A method of supplying power from a power system having a plurality of power storage devices capable of controlling power supply to the load or storage of power from the power system to a load in an area to be supplied with power Because
Detecting the overload status of the power transmission equipment, the voltage status and the frequency of the power system, which is the system status in the area;
Based on a predetermined parameter related to power transmission efficiency between each of the plurality of power storage devices and the power system, a control order for enabling power transfer between the power storage device and the power system A step of determining
Controlling the plurality of power storage devices based on the detected system state according to the determined control order of the power storage devices;
A power supply method.

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