JP2008125290A - Isolated operation method and system of low voltage system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To utilize the capacity of a distributed power supply in the consumer of a low voltage system effectively when a high voltage system is faulty. <P>SOLUTION: A low voltage system 3 which is in system interconnection with distributed power supplies 1A and 1B and supplies power to a plurality of consumers 2A, 2B and 2C including at least one consumer 2A having a distributed power supply 1A, is isolated from its upper system, i.e. a high voltage system 4, when it is faulty, and the voltage of the low voltage system 3 is maintained by one distributed power supply which is in system interconnection with the low voltage system 3. Excess and deficiency of power are calculated for every consumer 2A, 2B, 2C, and surplus power is supplied from a consumer having excess power to a consumer for which power is insufficient. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a low-pressure system independent operation method and a low-voltage system independent operation system. More specifically, the present invention provides a self-supporting low-voltage system when supplying power to a plurality of consumers and disconnecting a low-voltage system in which at least one distributed power source is connected to the system from a high-voltage system that is a higher system. The present invention relates to an operation method and a self-sustaining operation system of a low-voltage system.

  In recent years, the spread of distributed power sources such as photovoltaic power generation has been increasing with increasing environmental awareness. These distributed power sources are generally grid-connected to the power company's distribution system, and surplus power in sunny weather is sold to the power company. When output cannot be expected such as at night, electricity is purchased from the power company. Is possible.

However, a distributed power source connected to a commercial power distribution system needs to stop power generation from the standpoint of preventing isolated operation when a power failure occurs in the commercial power distribution system. When using electricity on the customer premises, it is necessary to manually connect the target device (load) to the self-sustaining operation circuit. In this case, power is supplied to the load from the distributed power source. However, when the power consumption of the load exceeds the power generation amount of the distributed power source, the distributed power source is stopped to protect the equipment, and supply is not possible. It becomes possible. Conversely, when the amount of power generated by the distributed power source exceeds the amount of power used by the load, it is possible to effectively use the power generation capacity of the distributed power source to suppress the output of the distributed power source according to the amount of load power. Can not. Also, customers who do not have a distributed power source will continue to be out of power even if the low-voltage system is normal. Furthermore, it is necessary to change the connection from the self-sustained operation circuit of the distributed power source to the constant circuit again after the system power is restored.
NEC Electronics Distributed Power System Interconnection Expert Group, “Distributed Power System Interconnection Technology Guidelines JEAG9701-2001”, NEC Corporation, January 2002 Energy Forum, “Guidelines for Power System Integration Technical Requirements 2003”, Energy Forum, October 2003

  An object of the present invention is to provide a low-voltage system self-sustained operation method and a low-voltage system self-sustained operation system that can effectively utilize the capability of a distributed power source possessed by a customer when a high-voltage system is abnormal. Another object of the present invention is to provide a self-sustaining operation method for a low-voltage system and a self-sustaining operation system for a low-voltage system that do not require manual connection change for a customer's self-sustained operation.

  In order to achieve this object, the low-voltage system self-sustained operation method according to claim 1 supplies power to a plurality of consumers including at least one customer having a distributed power source, and the distributed power source is connected to the grid. The low-voltage system is separated from the high-voltage system when it is abnormal, and the voltage of the low-voltage system is maintained by one of the distributed power sources connected to the low-voltage system. The excess or deficiency of power is calculated every time, and the surplus power of the consumer with surplus power is supplied to the consumer with shortage of power.

  Therefore, when an abnormality such as a power failure occurs in the high-voltage system, which is the upper system, the low-voltage system is disconnected from the high-voltage system, and the low-voltage system starts independent operation. The voltage of the entire low-voltage system after disconnection is maintained by one predetermined distributed power source (master distributed power source). When the master distributed power source generates AC, the voltage can be maintained as it is by the master distributed power source. However, when the master distributed power source generates DC, By switching the operation mode from the current control mode to the voltage control mode, the voltage is maintained using the inverter as a voltage source.

  A consumer having a distributed power source generates surplus power when the “power generation amount of the distributed power source” is larger than the “power consumption amount of the load”. The generated surplus power is reversely flowed to the low-voltage system and supplied to consumers who lack power. Here, it is thought that the case where the customer who does not have the distributed power source is the target as the customer who receives the supply of surplus power, but depending on the case, the customer who does not have the distributed power source and the distributed type It is also conceivable to target consumers who have a power source but whose “power generation amount of the distributed power source” is smaller than the “load usage amount” and lacks power.

  The self-sustained operation method of the low-voltage system according to claim 2 covers the load fluctuation of the low-voltage system that cannot respond at the output change rate of the distributed power source that maintains the voltage of the low-voltage system by charging and discharging the power storage device. . Therefore, it is possible to cope with the case where the load fluctuation of the low voltage system is faster than the output change of the distributed power source.

  Further, the self-sustaining operation method of the low-voltage system according to claim 3 solves the shortage of electric power when the electric power is still insufficient for a consumer who does not have a distributed power source even if surplus power is supplied. The load is cut off in order from the lowest priority. Therefore, the load usage required in the customer premises is reduced, and it is possible to continue to supply power to a load with high priority.

  The self-sustained operation method of the low-voltage system according to claim 4 is for a consumer having a distributed power source, when power is insufficient, disconnects the consumer from the low-voltage system, and prioritizes the load until the power shortage is resolved. In order from the lowest to the lowest. Therefore, the customer is in an independent operation. The amount of load used required in the customer premises is reduced, and power can be continuously supplied to loads with high priority.

  Furthermore, the invention described in claim 5 is a self-operating system of a low voltage system in which a customer having a distributed power source and a customer not having a distributed power source are interconnected, and the low voltage system is a higher voltage A switch that is separated from the high-voltage system when the system is abnormal, a master distributed power source that maintains the voltage of the low-voltage system when the low-voltage system is separated from the high-voltage system, and the demand provided for each customer A consumer management device that calculates excess or deficiency of electric power in the house, and the consumer management device of a consumer having a distributed power source other than the master distributed power source uses the distributed power source of the consumer when surplus power is generated When the grid is connected to the low-voltage system and no surplus power is generated, the customer is disconnected from the low-voltage system.

  Therefore, when an abnormality such as a power failure occurs in the high-voltage system, which is the host system, the switch is opened, the low-voltage system is disconnected from the high-voltage system, and the low-voltage system starts independent operation. The voltage of the entire low-voltage system after the disconnection is maintained by one master distributed power source. Distributed power sources other than the master distributed power source operate in cooperation with the master distributed power source. The customer management device calculates the excess or deficiency of the electric power in the customer, and if surplus electric power is generated, the distributed power source is connected to the low voltage system. For this reason, surplus electric power flows backward to the low-voltage system and is supplied to consumers who lack power because they do not have a distributed power source. Further, when no surplus power is generated, the customer is disconnected from the low-voltage system and autonomous operation is performed.

  In the self-sustained operation method of the low-voltage system according to claim 1, the low-voltage system in which power is supplied to a plurality of consumers including at least one customer having a distributed power source and the distributed power source is grid-connected, Separated from the high-voltage system in the event of an abnormality in the high-voltage system, and maintained the voltage of the low-voltage system with one of the distributed power sources connected to the low-voltage system. Calculate and supply surplus power of consumers with surplus power to consumers with shortage of power, so that it is possible to effectively utilize surplus power of distributed power sources linked to the low voltage system when the high voltage system is abnormal it can. That is, if the power generation amount of a distributed power source possessed by a consumer is larger than the load usage amount in the customer premises, the load usage amount is not adjusted by reducing the output of the distributed power source and adjusting the power generation amount to the load usage amount. Since the surplus power is distributed to other consumers as surplus power, the capacity of the distributed power source can be used effectively. In addition, a consumer who does not have a distributed power source can be supplied with surplus power, so that a power failure can be avoided. Furthermore, there is no need for a customer having a distributed power source to manually change the circuit connection in order to use a load when a commercial power distribution system fails.

  In the self-sustaining operation method of the low-voltage system according to claim 2, the load fluctuation of the low-voltage system that cannot respond at the output change rate of the distributed power source that maintains the voltage of the low-voltage system is covered by charging and discharging of the power storage device. Therefore, even when the load fluctuation of the low-voltage system is faster than the output change of the distributed power supply, it is possible to cope with the load fluctuation of the low-voltage system.

  Further, in the self-sustaining operation method of the low-voltage system according to claim 3, the shortage of power is solved when the customer who does not have the distributed power supply still receives the supply of surplus power and still lacks power. Since the load is cut off in order from the low priority, the power required in the customer premises is reduced, and the power can be continuously supplied to the high priority load. .

  Further, in the self-sustained operation method of the low-voltage system according to claim 4, for a consumer having a distributed power source, in the case of power shortage, the customer is disconnected from the low-voltage system, and the load is prioritized until the power shortage is resolved. Since the cut-off is performed in order from the lowest, the customer becomes independent operation. Electric power required in the customer premises is reduced, and electric power can be continuously supplied to a load having a high priority.

  Furthermore, in the self-sustained operation system of the low-voltage system according to claim 5, a switch that separates the low-voltage system from the high-voltage system in the event of an abnormality in the high-voltage system that is a higher system, and a low-voltage system when the low-voltage system is separated from the high-voltage system A distributed power source other than the master distributed power source, comprising one master distributed power source for maintaining the system voltage and a customer management device that is provided for each customer and calculates excess or deficiency of power in the customer. When the surplus power is generated, the consumer management device of the customer having the power supply connects the customer's distributed power source to the low voltage system, and when the surplus power does not occur, the customer's distributed power source is Since it is disconnected from the system, surplus power of the distributed power source connected to the low-voltage system can be effectively utilized when the high-voltage system is abnormal. That is, if the power generation amount of a distributed power source possessed by a consumer is larger than the load usage amount in the customer premises, the load usage amount is not adjusted by reducing the output of the distributed power source and adjusting the power generation amount to the load usage amount. Since the surplus power is distributed to other consumers as surplus power, the capacity of the distributed power source can be used effectively. In addition, a consumer who does not have a distributed power source can be supplied with surplus power, so that a power failure can be avoided. Furthermore, there is no need for a customer having a distributed power source to manually change the circuit connection in order to use a load when a commercial power distribution system fails.

  Hereinafter, the configuration of the present invention will be described in detail based on the best mode shown in the drawings.

  FIG. 1 shows an example of an embodiment of a low-pressure system self-sustaining operation system of the present invention. This low-voltage self-sustained operation system (hereinafter simply referred to as self-sustained operation system) is a system in which customers 2A, 2B having distributed power sources 1A, 1B and customers 2C having no distributed power sources are connected to each other. Then, the switch 5 that separates the low-voltage system 3 from the high-voltage system 4 in the event of an abnormality in the high-voltage system 4 that is the upper system, and the voltage of the low-voltage system 3 is maintained when the low-voltage system 3 is separated from the high-voltage system 4 A master distributed power source 1A, and a customer management device 6 provided for each of the consumers 2A, 2B, 2C to calculate the excess or deficiency of power in the consumers 2A, 2B, 2C. The customer management device 6 of the customer 2B having the distributed power source 1B other than the distributed power source 1A connects the distributed power source 1B of the customer 2B to the low voltage system 3 when surplus power is generated, and surplus power. Does not occur The case is intended to separate the consumer 2B from the low pressure line 3. In addition, the low-voltage system self-sustained operation method (hereinafter simply referred to as self-sustained operation method) of the present invention supplies power to a plurality of consumers including at least one consumer having a distributed power source and distributes power sources 1A and 1B. Is separated from the high-voltage system 4 when the high-voltage system 4 which is the higher-level system is abnormal, and one of the distributed power sources connected to the low-voltage system 3, that is, master distribution The voltage of the low voltage system 3 is maintained by the type power supply 1A, the excess or deficiency of power is calculated for each of the consumers 2A, 2B, and 2C, and the surplus power of the consumers with surplus power is supplied to the consumers with deficient power Is. In the present embodiment, surplus power is supplied to the consumer 2C that does not have a distributed power source as a consumer with insufficient power.

  The low voltage system 3 is connected to the high voltage system 4 via a pole transformer 7. A switch 5 that disconnects the low-voltage system 3 from the high-voltage system 4 is provided immediately downstream of the pole transformer 7. The switch 5 is, for example, a low-voltage switch 5 with a semiconductor switch that can be remotely operated. The switch 5 mitigates the switching surge and realizes a high-speed switching operation. The switch 5 is opened and closed by the low-voltage system management device 8 through a wired or wireless communication line. That is, in the present invention, in order to protect the low voltage system 3, the low voltage switch 5 is installed. In principle, this is the same switch as that of a general household breaker, and a semiconductor switch (diode is installed to alleviate the switching surge). And is opened / closed by an operation from the low-voltage system management device 8.

  The low-voltage system 3 is a power distribution system that supplies power to a large number of consumers. As consumers, there are consumers 2A and 2B having distributed power sources 1A and 1B, and consumers 2C having no distributed power sources. The distributed power sources 1A and 1B generate, for example, direct current, and are connected to power conditioners 9A and 9B having an inverter function, and the power conditioners 9A and 9B are interconnected to the low voltage system 3. Further, the consumers 2A and 2B having the distributed power sources 1A and 1B are provided with the power storage device 10. However, the power storage device 10 is not essential, and the power storage device 10 may be omitted. Further, the consumer 2 </ b> C that does not have a distributed power source may include the power storage device 10. The power storage device 10 is, for example, a storage battery.

  Among the consumers 2A and 2B having the distributed power sources 1A and 1B, the main of the slave customer 2B described later is connected to the low-voltage system 3 via the switch 11. The switch 11 is a switch with a semiconductor switch, for example. The switch 11 relieves switching surge and realizes high-speed switching operation. The switch 11 is opened and closed by a customer management device 6 described later through a wired or wireless communication line. That is, a switch 11 having a semiconductor switch similar to the switch 5 in principle is provided between the slave customer 2B and the low-voltage system 3, so that the switching surge can be reduced and the switching operation can be performed at high speed. In addition, on / off control from the outside is possible. A signal for on / off control from the outside is transmitted from the customer management device 6.

  For example, a plurality of loads 12, that is, electric devices are connected to the distribution lines of the consumers 2 </ b> A, 2 </ b> B, and 2 </ b> C. In FIG. 1, a plurality of loads 12 are collectively shown in one block for each customer 2A, 2B, 2C. Each load 12 is set in advance with a priority order for selective blocking.

  An example of factors for determining the priority order is shown in FIG. For example, the priority order is determined in the order of designation of consumers 2A, 2B, 2C → power consumption of load 12 → power consumption fluctuation degree of load 12 → device ID. That is, when the consumers 2A, 2B, and 2C specify the priority order, this priority order is adopted. When the consumers 2A, 2B, and 2C are not specified, the priority order is determined based on the power consumption of the load 12. For example, the priority order of the load 12 with high power consumption is lowered and shut off at an early stage, and the priority order of the load 12 with low power consumption is raised and shut off at a late stage. Further, when not based on the power consumption of the load 12, the priority order is determined based on the power consumption fluctuation degree of the load 12. For example, the priority of the load 12 having a large power consumption fluctuation is lowered and shut off at an early stage, and the priority of the load 12 having a small power consumption fluctuation is raised and shut off at a late stage. When these priority orders are not adopted, the priority order based on the device ID is adopted. For example, when the device ID is large, the priority is increased and the device ID is blocked at a later stage. Here, the device ID is an identification number unique to the home appliance (load) given by the consumer. In order to determine the control priority when the priority, power consumption, and power consumption fluctuation are all the same. Adopted.

  When the low voltage system 3 is separated from the high voltage system 4, the voltage of the low voltage system 3 is maintained by one of the distributed power sources connected to the system. Here, the distributed power source used for maintaining the voltage is the master distributed power source 1A, the customer 2A having the master distributed power source 1A is the master customer 2A, and the distributed power source 1B is other than the master distributed power source 1A. The customer 2B is the slave customer 2B. When there is only one distributed power source connected to the low-voltage system 3, the distributed power source is the master distributed power source 1A. On the other hand, when a plurality of distributed power sources are connected to the low-voltage system 3, it is desirable to select a distributed power source having a larger capacity and capable of output control as the master distributed power source 1A. The inverter function of the power conditioner 9A to which the master distributed power source 1A is connected can instantaneously switch the operation control mode from current control to voltage control. By switching the operation control mode from current control to voltage control, the low voltage system 3 separated from the high voltage system 4 can be operated independently. When the operation control mode is switched to the voltage control mode, the power conditioner 9A of the master distributed power source 1A generates, for example, a voltage of 200 V 50 Hz.

  In FIG. 1, four customers 2A, 2B, 2B, and 2C are shown for convenience. In other words, as will be described later, there are three types of four-state customers 2A, 2B, 2B, and 2C, which are listed one by one. The number of master customers 2A must be one, but the number of other customers 2B, 2B, 2C is not limited to one. However, since the self-sustained operation of this embodiment supplies surplus power to the customer 2C that does not have a distributed power source, at least one customer 2C that does not have a distributed power source is required. On the other hand, the slave customer 2B may be zero.

  The distributed power sources 1A and 1B generate direct current, for example, and are, for example, a solar power generation device, a wind power generation device, a micro gas turbine (MGT) power generation device, a fuel cell power generation device, or the like. In particular, it is desirable that the master distributed power source 1A has such a large output that power can be supplied to the consumer 2C that does not have the distributed power source when the low voltage system 3 is disconnected from the high voltage system 4. A relatively large capacity power source capable of output control such as a gas turbine power generator is preferable. Load fluctuations of the low-voltage system 3 that cannot respond at the output change rate of the distributed power source 1A of the master customer 2A are covered by charging / discharging from the power storage device 10. That is, the low-voltage system 3 is provided with a measuring device 14 that measures the frequency and voltage of the system. Based on the signal from the measuring device 14, the customer management device 6 of the master customer 2A The load state, that is, the amount of power used is constantly monitored. The customer management device 6 of the master customer 2A changes the frequency and voltage in the low-voltage system 3 when the balance between the load status in the low-voltage system 3 and the power generation amount of the master distributed power source 1A is lost. The deviation amount of the power storage device 10 is feedback-controlled, and the charge / discharge amount of the power storage device 10 is controlled so that the frequency and voltage approach the target value. The master distributed power source 1A itself (control of the speed governor and the like in the case of a synchronous generator) can change its output by changing the command value of the power generation amount, but the control delay of the master distributed power source 1A and the command value Control delay occurs for calculation. Since the low voltage system 3 cannot be maintained when the deviation amount exceeds a certain amount, the power storage device 10 having a high control speed compensates for the control delay of the master distributed power source 1A.

  Each customer 2A, 2B, 2C is provided with a customer management device 6. The customer management device 6 has a communication function, and can exchange information with the low-voltage system management device 8. Further, the consumer management device 6 controls the distribution boards / loads 12 / distributed power sources of each consumer 2A, 2B, 2C and measures the amount of power. The distributed power sources 1A and 1B are controlled by transmitting an operation / stop command and active / reactive power generation amounts to the distributed power sources 1A and 1B through a dedicated communication circuit. The power generation amounts of the distributed power sources 1A and 1B are also acquired from the distributed power sources 1A and 1B through the same communication circuit. That is, the distributed power sources 1A and 1B are provided with a communication device that communicates with the customer management device 6. In addition, when the load 12 itself does not have a communication function, the power consumption of the load 12 is measured by installing a current sensor in each branch circuit in the customer premises, Along with the information on the voltage sensor of the panel, the calculation is performed by performing digital calculation in the customer management device 6. Further, when the load 12 itself has a communication function, the amount of power used is directly collected from the load 12 itself through, for example, a home LAN.

  The customer management device 6 of the master customer 2A can supply a setting change command using the communication network with the power conditioner 9A, and can operate the operation control mode of the inverter function of the power conditioner 9A. .

  The customer management device 6 stores in advance the circuit configuration within the customer premises, the type and performance of the distributed power sources 1A and 1B, the type, number, and position of the connected load 12.

  The customer management device 6 can calculate the power generation amount of the distributed power sources 1A and 1B (distributed power source output estimation). When the distributed power sources 1A and 1B are solar power generators or wind power generators, the predicted power generation amount is calculated based on the solar radiation amount prediction information and the wind speed prediction information. The customer management device 6 stores a correspondence relationship between the solar radiation amount / wind speed and the power generation amount in advance, and calculates the predicted power generation amount by applying the solar radiation amount prediction information / wind speed prediction information to the correspondence relationship. These solar radiation amount prediction information and wind speed prediction information are provided from the operation management sub-device 13 through the low-voltage system management device 8, for example. In the case where the distributed power sources 1A and 1B are other than the solar power generation device and the wind power generation device, the operation status of the future load 12 is predicted from the data on the operation status of the past load 12, and based on this prediction Then, the operation pattern of the distributed power sources 1A and 1B is determined, and the power generation amount is calculated from the operation pattern. When the distributed power sources 1A and 1B are cogeneration equipment such as a gas engine, not only electricity but also heat is generated simultaneously during operation. Considering the balance between the customer's heat load (mainly hot water supply load) and the power load, the distributed power sources 1A and 1B are operated so that both can be used up well.

  The customer management device 6 can estimate the amount of power that can be used by the power storage device 10. There is a certain relationship between the amount of power that can be used by the power storage device 10 and the voltage of the power storage device 10. An example of this relationship is shown in FIG. For example, if the voltage of the power storage device 10 is 250 V, the customer management device 6 estimates that the available power amount is about 2000 W. For example, the power storage device 10 is provided with a voltage sensor (not shown), and the voltage of the power storage device 10 is measured based on a signal from the voltage sensor to estimate the amount of power that can be used.

  The customer management device 6 constantly monitors the operating / stopped state of each load 12 and stores the power consumption for each load 12 in advance. The customer management device 6 calculates the total amount of power used by the load 12 in operation, thereby calculating the load usage of the entire consumer. When the load 12 has a communication function, the operating state of the load 12 is transmitted from the load 12 to the consumer management device 6 through, for example, an indoor LAN. Thereby, the customer management apparatus 6 can monitor the operating / stopped state of each load 12.

  The customer management device 6 calculates the excess or deficiency of power based on the power generation amount of the distributed power sources 1A and 1B, the amount of power available to the power storage device 10, and the load usage. That is, by subtracting the load usage on the power consuming side from the total of the power generation amount of the distributed power sources 1A and 1B on the power generation side and the available power amount on the power storage device 10, Calculate excess and deficiency. When the calculated value is positive, surplus current is generated. Note that the amount of power generated by the distributed power source of the customer 2C and the amount of power that can be used by the power storage device are zero.

  The customer management device 6 is configured by a computer, for example. That is, by installing a program showing the procedure of the above-described function in a computer, an operation unit and a control unit are configured in cooperation with hardware resources such as an arithmetic device, a storage device, and an input / output device. 6 exhibits the above-mentioned function.

  The low-voltage system management device 8 is a host device of the customer management device 6, has a communication function, and can send and receive signals to and from the customer management device 6. Further, the low-voltage system management device 8 can open and close the switch 5. Further, the low-voltage system management device 8 can transmit and receive signals to and from the higher-level operation management sub-device 13. The low-voltage system management device 8 is configured by a computer, for example. That is, a program indicating the procedure of the above-described functions for operating and monitoring signals by transmitting / receiving signals to / from the switch 5, customer management device 6, operation management sub-device 13 and the like is installed in the computer. Thus, the operation means and the control means are configured in cooperation with hardware resources such as an arithmetic device, a storage device, and an input / output device, and the low-voltage system management device 8 exhibits the above-described functions.

  The operation management sub-device 13 monitors abnormalities such as a power failure or a voltage drop in a section (high-voltage distribution unit) of the high-voltage system 4 sandwiched between the switch 5 and a loop controller (not shown), for example. A switch with sensor (not shown) is installed in the high-voltage system 4, and the operation management sub-device 13 detects an abnormality in the high-voltage system 4 based on information from this sensor-equipped switch (information on zero-phase current and zero-phase voltage). Is detected. When the zero-phase voltage / current at both ends managed by the operation management sub-device 13 exceeds a certain threshold and the current direction is different from the normal direction, the operation management sub-device 13 determines that an abnormality has occurred in the high-voltage system 4. . Further, the operation management sub-device 13 collects solar radiation amount prediction information and wind speed prediction information from, for example, a weather-related information source through a communication line. The operation management sub apparatus 13 is configured by a computer, for example. That is, by installing a program showing the procedure of the above-described functions in a computer, a judgment unit, an information collection unit, etc. are configured in cooperation with hardware resources such as an arithmetic device, a storage device, an input / output device, etc. The sub device 13 exhibits the above-described functions.

  In the self-sustained operation of the low voltage system of the present invention, when the upper system (high voltage system 4) is abnormal, the entire low voltage system 3 is disconnected from the upper system, and the master distributed power source 1A connected to the low voltage system 3 maintains the voltage of the entire low voltage system 3 The slave distributed power supply 1B continues to supply surplus power to the low-voltage system 3 by performing cooperative operation by the operation of the customer management apparatus 6 that has received an independent command from the low-voltage system management device 8. Here, the customer 2C is a non-distributed power source customer, the customer 2A is a customer (master customer 2A) having a master distributed power source 1A that maintains the voltage of the entire low voltage system 3 and adjusts the supply and demand. 2B is a consumer (slave consumer 2B) having a slave distributed power source 1B.

  The master customer 2A is a customer who owns the distributed power source 1A capable of maintaining the voltage of the low-voltage system 3, and adjusts the load balance in the low-voltage system by adjusting the output of the distributed power source 1A and charging / discharging the power storage device 10. Do. That is, the customer management device 6 determines and operates the power generation amount of the distributed power source 1A and the charge / discharge amount of the power storage device 10 so as to maintain the frequency and voltage in the low voltage system 3 within a certain range.

  The slave customer 2B performs an interconnection operation when the output of the distributed power source 1B (power generation amount) is larger than the load 12, that is, a reverse power flow is possible, according to the self-sustained command from the low-voltage system management device 8. Accommodate power to 2C. When the load 12 is larger than the output of the distributed power source 1B, the operation shifts to the customer premises independent operation.

  The customer 2C that does not have a distributed power source can be supplied with power to the load 12 according to the power generation surplus of the distributed power sources 1A and 1B owned by the other customers 2A and 2B. The low-voltage system management device 8 calculates the available amount, and notifies each customer 2C of the amount of power that can be supplied. When the interchangeable amount is zero, the load 12 other than the necessary minimum important load 12 is cut off.

  By performing the control as described above, it is possible to effectively use the outputs of the distributed power sources 1A and 1B, and it is possible to continue supplying power to the consumers 2C who do not own the distributed power source.

  For example, the low-voltage system 3 is shifted to a self-sustained operation by either detecting a high-voltage system abnormality in the low-voltage system management device 8 or receiving a self-sustained operation command from the operation management sub-device 13 via the low-voltage system management device 8. System reconnection from the independent operation is performed by a command from the operation management sub-device 13 via the low-voltage system management device 8, for example. When the grid is reconnected, the power storage device 10 compensates for the power used by the load 12 to be reconnected, so that the grid can be reconnected in a state where the connection point power is zero and is supplied to the high voltage system 4. The shock is small.

  More specific description will be given based on FIGS. 2 is a flowchart for the low-voltage system management device 8, FIG. 3 is a flowchart for the customer management device 6 of the master customer 2A, FIG. 4 is a flowchart for the customer management device 6 of the slave customer 2B, and FIG. It is a flowchart about the consumer management apparatus 6 of the consumer 2C which does not have a type | mold power supply. 2 to 5, the amount of power that can be used by the power storage device 10 is included in the amount of power generated by the distributed power sources 1A and 1B. That is, in the description of FIGS. 2 to 5, “power generation amount of the distributed power source” is “suppliable power amount” including “discharge amount / usable power of power storage device 10”.

  When the operation management sub-device 13 detects an abnormality such as a power failure or a voltage drop occurring in the high-voltage system 4, the low-voltage system management device 8 is notified of the occurrence of the abnormality. Receiving the abnormality detection signal from the operation management sub-device 13, the low-voltage system management device 8 opens the low-voltage switch 5 and transmits a self-sustained command to the customer management device 6 of each customer 2A, 2B, 2B, 2C ( Steps S31 and S32 in FIG.

  In the master customer 2A, when the customer management device 6 receives the independence command from the low voltage system management device 8 (step S41 in FIG. 3), the customer management device 6 sets the operation control mode of the inverter function of the power conditioner 9A. Switching from current control to voltage control (step S42). Thereby, the voltage of the low voltage system 3 separated from the high voltage system 4 is maintained. Further, the customer management device 6 calculates “power generation amount of distributed power source” and “load usage amount” and “amount of possible interconnection” (= “power generation amount of distributed power source” − “load usage amount”). Is calculated (calculation of excess or deficiency of power), and the calculated “interconnectable amount” is transmitted to the low-voltage system management device 8 (step S43). The customer management device 6 repeatedly executes step S43.

  In the slave customer 2B, when the customer management device 6 receives the independence command from the low-voltage system management device 8 (step S51 in FIG. 4), the customer management device 6 opens the switch 11 and makes the customer 2B low-pressure. Disconnect from system 3 (step S52). Thereby, the customer 2B is shifted to the self-supporting operation on the premises. Further, the customer management device 6 calculates “the amount of power generated by the distributed power source” and “the amount of load used”, and compares these magnitude relationships (step S53). If “distributed power generation amount”> “load usage amount”, the process proceeds to step S54 to determine whether or not there is a load 12 being cut off. Now, since there is no load 12 that is cut off immediately after shifting to the independent operation, the process proceeds to step S55, the switch 11 is closed, and the customer 2B is reconnected to the low-voltage system 3. As a result, surplus power corresponding to the “interconnectable amount” is reversely flowed to the low-voltage system 3. Thereafter, the customer management device 6 calculates “amount of possible interconnection” (calculation of excess or deficiency of power) and transmits the calculated “amount of possible interconnection” to the low-voltage system management device 8 (step S56). After executing Step S56, the customer management device 6 returns to Step S53.

  On the other hand, if “the amount of power generated by the distributed power source” ≦ “the amount of load used” in step S53, the customer management device 6 continues the on-site independent operation without operating the switch 11 (step S57). That is, when there is not enough electric power to supply to the other customer 2C, the on-site independent operation is performed. Then, it progresses to step S58 and performs load selection interruption | blocking. That is, the load with the lowest priority among the currently operating loads 12 is blocked. In this embodiment, the loads 12 having the lowest priority are blocked one by one. However, the number of loads 12 to be blocked at a time is not limited to one, and a plurality of loads may be blocked at a time.

  In the load selection cutoff, the load 12 that supplies power is selected within a range that does not exceed the power generation amount of the distributed power source 1B, and the loads 12 other than the selected load 12 are cut off. The priority of the load 12 that supplies power is determined in advance.

  In the case where the load 12 has a communication function and can be remotely operated, the customer management device 6 directly turns on / off the load 12 using, for example, a wireless LAN or changes the operating state. . When the load 12 is a device that cannot be remotely operated, for example, a switch that can be remotely operated is provided immediately upstream of the load 12, and the customer management device 6 opens and closes the load 12 by opening and closing the switch. Operate on and off.

  After executing Step S58, the customer management device 6 returns to Step S53. Even if one load 12 is cut off by executing step S58, if “power generation amount of distributed power source” ≦ “load usage amount” still proceeds, the process proceeds again from step S53 → S57 → S58, and is currently operating. The load 12 having the lowest priority is blocked. In step S53, steps S53 → S57 → S58 → S53 are repeatedly executed until “distributed power generation amount”> “load usage amount” is satisfied, and the on-site independent operation is continued while the load selection is cut off.

  In step S57, when the switch 11 is already open, that is, when it is disconnected from the low-voltage system 3, that state is maintained, and when the switch 11 is closed, that is, connected to the low-voltage system 3. If it is, the operation to open the switch 11 is performed.

  As described above, for the customer 2B having the distributed power source 1B, in the case of power shortage, the customer 2B is disconnected from the low-voltage system 3, and the load 12 is changed in order from the lowest priority until the power shortage is resolved. Cut off.

  When “power generation amount of distributed power source”> “load usage amount” is satisfied by the load selection interruption, the customer management apparatus 6 proceeds from step S53 to S54, and determines whether or not there is a load 12 being interrupted. Since there is a load 12 being interrupted by the execution of step S58, the process proceeds to step S59 to determine whether or not the load 12 being interrupted can be recovered.

  In step S59, whether or not the load 12 being interrupted can be recovered is determined as follows. For example, the sum of the power consumption (hereinafter referred to as “cutting load usage amount”) of the load 12 to be recovered next out of the interrupted load 12 and the above “load usage amount” is calculated, Compare with "Amount". If “distributed power generation amount” ≧ “load usage amount” + “interrupted load usage amount”, it is determined that the load 12 being disconnected can be recovered, and “distributed power generation amount” < In the case of “load use amount” + “breaking load use amount”, it is determined that the load 12 being cut off cannot be recovered.

  Here, the load to be recovered next among the loads 12 being cut off is determined according to the priority order used when the load 12 is cut off. That is, the above-mentioned “distributed power generation amount” ≧ “load usage amount” + “interrupted load usage amount” is established for the load 12 with the highest priority (first load) among the interrupted loads 12 The first load 12 is the load to be recovered next. When the first load 12 is “distributed power generation amount” <“load use amount” + “interrupted load use amount”, the next highest priority among the interrupted loads 12 ( When “distributed power generation amount” ≧ “load use amount” + “breaking load use amount” is established for the second load), the second load 12 becomes the load to be recovered next. Further, when “the amount of power generated by the distributed power source” <“load usage” + “interrupted load usage” also for the second load 12, the next highest priority among the interrupted loads 12 is next. When “power generation amount of distributed power source” ≧ “load usage amount” + “interrupted load usage amount” is established for the thing (third load), the third load 12 becomes the load to be recovered next. Thereafter, similarly, the fourth load, the fifth load, and so on. In this way, the recoverable load 12 is determined according to the priority order. Then, when “distributed power generation amount” <“load use amount” + “cutoff load use amount” is satisfied for all the loads 12 being cut off, it is determined that the load cannot be recovered.

  In this way, the interrupted load 12 that does not exceed the “power generation amount of the distributed power source” even when recovered is recovered in order from the highest priority.

  If the load 12 can be recovered, the process proceeds to step S60 to recover the load 12. That is, energization to the load 12 is resumed. Thereafter, the process returns to step S53. On the other hand, if the load 12 cannot be recovered in step S59, the process directly returns to step S53.

  On the other hand, when all the interrupted loads 12 are recovered in step S54, the process proceeds from step 54 to step S55, the switch 11 is closed, and the customer 2B is reconnected to the low-voltage system 3. That is, when all the interrupted loads 12 are recovered and “power generation amount of the distributed power source”> “load usage amount”, the customer is reconnected to the low-voltage system 3 and the surplus power is reversed. At the same time, the possible interconnection amount is calculated and transmitted to the low-voltage system management device 8.

  In step S55, if the switch 11 is already closed, that is, if it is connected to the low-voltage system 3, that state is maintained, and if the switch 11 is open, that is, disconnected from the low-voltage system 3. If the switch 11 is closed, an operation to close the switch 11 is performed.

  In the customer 2C that does not have a distributed power source, when the customer management device 6 receives an independent command from the low-voltage system management device 8 (step S61 in FIG. 5), the customer management device 6 cuts off the predetermined load 12. (Step S62). For example, the load 12 other than the important load 12 is cut off, and the operation of only the important load 12 is continued. By cutting off some of the loads 12 at this stage, the load usage can be reduced. The load 12 to be cut off at this stage is determined in advance, and the customer management device 6 stores this. Thereafter, the load usage is calculated (calculation of excess or deficiency of power), and the value is transmitted to the low-voltage system management device 8 as an accommodation request amount (step S63).

  The low-voltage system management device 8 receives the possible amount of interconnection transmitted from the customer management devices 6 of the master customer 2A and the slave customer 2B (step S34 in FIG. 2), and the demand that does not have a distributed power source The accommodation request amount transmitted from the customer management device 6 of the house 2C is received (step 35). Then, it progresses to step S36 and the interchangeable amount is calculated. The calculation formula is shown in Formula 1. In addition, Formula 1 is a formula in the case where there are a plurality of consumers 2C that receive supply of surplus power, that is, consumers 2C that do not have a distributed power source, and consumers 2C that do not have a distributed power source as in this embodiment. In the case of one house, Equation 2 is obtained.

[Equation 1]
Accommodable amount (i) = Accommodated request amount (i) x Σ (interconnectable amount) / Σ (accommodated request amount)
Here, the interchangeable amount (i) is the interchangeable amount to the target consumer 2C. Further, the accommodation request amount (i) is the accommodation request amount from the target consumer 2C. Further, Σ (linkable amount) is a total of linkable amounts transmitted from the customer management devices 6 of the master customer 2A and the slave customer 2B. Further, Σ (accommodation request amount) is the sum of the accommodation request amounts transmitted from the customer management devices 6 of all the consumers 2C that do not have a distributed power source.

[Equation 2]
Accommodable amount = Accommodated request amount x Σ (interconnectable amount) / Acceptable amount
= Σ (Amount that can be connected)
Here, the interchangeable amount is an amount that can be accommodated to one customer 2C that does not have a distributed power source. The accommodation request amount is an accommodation request amount from one customer 2C that does not have a distributed power source. Further, Σ (linkable amount) is a total of linkable amounts transmitted from the customer management devices 6 of the master customer 2A and the slave customer 2B.

  In Formula 1, the total amount of possible interconnections of the surplus power supply side (master consumer 2A and slave consumer 2B) is interchanged with the surplus power supply side (customer 2C having no distributed power source). The distribution is made to each consumer 2C according to the ratio of the requested amount.

  The interchangeable amount obtained in this way is transmitted to the consumer management device 6 of the consumer 2C that does not have a distributed power supply (step S37). Then, it returns to step S33 and repeatedly performs step S33-step S37.

  Next, in step S64 of FIG. 5, the customer management device 6 of the customer 2C that has received the available amount from the low-voltage system management device 8 determines whether or not load selection should be blocked according to the available amount. (Step S65). In the customer 2C that does not have a distributed power source, if the available amount> the required amount of accommodation, it is possible to operate all the loads 12 that are desired to be operated by surplus power supplied from other customers. There is no need to perform load selection interruption. Accordingly, the customer management device 6 proceeds from step S65 to step S66 and determines whether or not there is a load 12 being cut off. Now, since there is no load 12 that is immediately after the transition to the independent operation and is not interrupted, the process directly returns to step S63.

  On the other hand, if “accommodable amount” ≦ “accommodation required amount” in step S65, the power is still insufficient even if the supply of surplus power is received. In this case, the process proceeds to step S67 and the load selection is cut off. The load 12 is shut off in order from the lowest priority until the power shortage is resolved. That is, the load with the lowest priority among the currently operating loads 12 is blocked. In this embodiment, the loads 12 having the lowest priority are blocked one by one. However, the number of loads 12 to be blocked at a time is not limited to one, and a plurality of loads may be blocked at a time.

  It should be noted that the interruption of the load 12 for the consumer 2C that does not have the distributed power supply is also performed when the load 12 is a device that can be remotely operated, similar to the load 12 of the consumers 2A and 2B having the distributed power supplies 1A and 1B. The customer management device 6 directly turns on or off the load 12 using a wireless LAN, for example, or changes the operating state. When the load 12 is a device that cannot be remotely operated, for example, a switch that can be remotely operated is provided immediately upstream of the load 12, and the customer management device 6 opens and closes the load 12 by opening and closing the switch. Operate on and off.

  After executing Step S67, the customer management device 6 returns to Step S63, recalculates the load usage amount, and transmits the value to the low-voltage system management device 8 as the accommodation request amount. Thereafter, a new interchangeable amount is received from the low-voltage system management device 8 (step S64). Then, even if one load 12 is shut off by executing step S67, if “accommodable amount” ≦ “accommodation request amount”, the process proceeds to step S67 again, and the load 12 that is currently operating is the most. Block low priority items. In step S65, steps S63, S64, S65, S67, and S63 are repeatedly executed until “accommodable amount”> “accommodation request amount”, thereby preventing a power failure while performing load selection interruption.

  As described above, when the power is still insufficient even when the supply of surplus power is received, the load 12 is shut off in order from the lowest priority until the power shortage is resolved.

  If “available amount”> “availability requested amount” is satisfied due to the load selection interruption, the customer management device 6 proceeds from step S65 to S66, and determines whether there is a load 12 being interrupted. Since there is a load 12 being interrupted by the execution of step S67, the process proceeds to step S68 to determine whether the load 12 being interrupted can be recovered.

  In step S68, as in step S59 of FIG. 4, whether or not the load 12 being cut off can be recovered is determined as follows. For example, the sum of the electric power used (hereinafter referred to as “interrupted load usage”) of the load 12 that is about to be recovered next and the above-mentioned “accommodation request amount (load usage)” is calculated. Compared to the "Available amount" of Then, if “available amount” ≧ “availability requested amount” + “interrupted load usage amount”, it is determined that the load 12 being disconnected can be recovered, and “available amount” <“availability requested amount” + In the case of “blocking load usage”, it is determined that the load 12 being blocked cannot be recovered.

  Here, the load to be recovered next among the loads 12 being cut off is determined according to the priority order used when the load 12 is cut off. That is, when the above-mentioned “accommodable amount” ≧ “accommodation request amount” + “interrupted load usage amount” is established for the load 12 with the highest priority (first load) among the interrupted loads 12, The first load 12 becomes a load to be recovered next. Further, when “available amount” <“availability requested amount” + “blocking load usage amount” for the first load 12, the next highest priority among the blocked loads 12 (the second load) For “load”, when “accommodable amount” ≧ “accommodation request amount” + “interrupted load usage amount” is satisfied, the second load 12 becomes a load to be recovered next. Further, when “containable amount” <“accommodation request amount” + “blocking load usage amount” also applies to the second load 12, the next highest load among the blocked loads 12 (3 When “containable amount” ≧ “accommodation request amount” + “blocking load use amount” is established, the third load 12 becomes a load to be recovered next. Thereafter, similarly, the fourth load, the fifth load, and so on. Thus, the recoverable load 12 is determined according to the priority order. When all the loads 12 being cut off satisfy the above-mentioned “accommodable amount” <“accommodation request amount” + “cut off load usage amount”, it is determined that the load cannot be recovered.

  In this way, the interrupted loads 12 that do not exceed the “accommodable amount” even if they are recovered are recovered in order from the highest priority.

  If the load 12 can be recovered, the process proceeds to step S69 to recover the load. That is, energization to the load 12 is resumed. Thereafter, the process returns to step S63. On the other hand, if the load can be recovered in step S68, the process directly returns to step S63.

  On the other hand, when all the loads 12 that have been interrupted in step S66 are recovered, the process returns to step S63, and thereafter, steps S63 to S69 are repeatedly executed.

  Signal transmission / reception between the low-voltage system management device 8 and each customer management device 6 is performed in synchronization. The low-voltage system management device 8 and each customer management device 6 repeat the above steps to supply the surplus power of the customers 2A and 2B having the distributed power sources 1A and 1B to the customer 2C having no distributed power source, The self-sustained operation of the low-voltage system 3 separated from the high-voltage system 4 is performed.

  As described above, when the power generation amount of the distributed power source 1B of the customer 2B is larger than the load usage amount in the customer 2B premises, the output of the distributed power source 1B is reduced to match the power generation amount with the load usage amount. However, since the amount exceeding the load usage is supplied as surplus power to the other consumers 2C, the capacity of the distributed power source 1B can be effectively utilized. Moreover, since the consumer 2C which does not have a distributed power supply can receive supply of surplus electric power, it can avoid a power failure. Further, since the customers 2A and 2B having the distributed power sources 1A and 1B use the load 10 at the time of a power failure in the high-voltage system 4, it is not necessary to manually change the circuit connection, which is convenient.

  Moreover, since the low voltage | pressure system management apparatus 8 and each customer management apparatus 6 repeat the above-mentioned step, it can respond to the fluctuation | variation of the electric power generation amount and load usage-amount of distributed power supply 1A, 1B satisfactorily quickly.

  When the abnormality of the high-voltage system 4 is resolved, the operation management sub-device 13 that has detected the abnormality transmits a reconnection command to the low-voltage system management device 8. In response to this command, the low-voltage system management device 8 closes the switch 5 to link the low-voltage system 3 to the high-voltage system 4 and sends an end command to the customer management devices 6 of the respective consumers 2A, 2B, 2C. To end the autonomous operation.

  The customer management device 6 of the master customer 2A that has received the termination command monitors the effective value and phase of the voltage on the primary side (the high voltage system 4 side) of the switch 5 with the measuring device 15, and the secondary side (low voltage) The effective value and phase of the voltage on the system 3 side) are monitored by the measuring device 14, and the distributed power source is set so that the effective value and phase of the primary side voltage value coincide with or close to the effective value and phase of the secondary side voltage. 1A is controlled. When the phase difference and potential difference between the primary side and the secondary side fall within a certain range, the customer management device 6 supplies a signal to the low-voltage system management device 8, and the low-voltage system management device 8 that receives this signal is a switch. 5 is thrown. Further, the customer management device 6 supplies a signal to the low-voltage system management device 8 and at the same time changes the operation control mode of the power conditioner 9A from the voltage control mode to the current control mode while maintaining the current value. Thereafter, if there is a load 12 that has been selectively cut off, it is returned in sequence.

  In addition, the customer management device 6 of the slave customer 2B that has received the termination command receives the independent operation cancellation command from the low-voltage system management device 8 that has confirmed that the switch 5 is turned on and the operation mode of the power conditioner 9A has been switched. Thus, the phase / effective value of the voltage on the customer 2B side is controlled to approach the phase / effective value on the low voltage system 3 side, and the switch 11 is turned on when the phase difference and the potential difference are within a certain range. . Thereafter, the load 12 that has been selectively cut off is sequentially returned.

  In addition, the customer 2 </ b> C that has received the termination instruction sequentially returns the blocked load 12. When the storage battery remaining amount of the power storage device 10 of each consumer 2A, 2B is small, charging is performed within the contracted capacity range.

  In the conventional system, after the power failure is restored, the load 12 maintains the state before the power failure. On the other hand, the distributed power source generates power after a certain time (for example, 1 minute) from the viewpoint of equipment protection. Start. For this reason, when the distributed power source is generating power in a state before the power failure, the load 12 becomes excessive at the time of reconnection immediately after the power failure is restored, and the shock given to the high-voltage system 4 is increased. On the other hand, in this self-sustained operation system, the customer management device 6 has a load fluctuation compensation function, which compensates the fluctuation of the load 12 with a time constant, for example, 1 minute. That is, the average of the load 12 from the current time to, for example, one minute before, is used as the load power command value, and the variation is compensated by the power storage device 10. For this reason, even if the load 12 fluctuates suddenly, the change is smoothed, for example, for 1 minute. Since the load 12 before the reconnection is zero, the load 12 increases from zero to the usage amount of the load 12 before the power failure, for example, during one minute during the reconnection. By starting the distributed power supply during this time, an excessive load state can be avoided and the shock to the high voltage system 4 can be reduced.

  Further, when the outputs of all the distributed power sources 1A and 1B and the remaining amount of the power storage device 10 become 0, the low-voltage system management device 8 forcibly ends the autonomous operation.

  The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention.

  For example, in the above description, the slave customer 2B includes the power storage device 10 in addition to the master customer 2A, but the slave customer 2B may not include the power storage device 10.

  In the above description, the distributed power sources 1A and 1B that generate direct current are used. However, the distributed power sources 1A and 1B that generate alternating current can also be used. Examples of distributed power sources 1A and 1B that generate alternating current include wind power generators, small hydroelectric generators, diesel engine power generators, gas engine power generators, gas turbine power generators, micro gas turbine (MGT) power generators, and waste A power generator or the like can be used. In the case of using the distributed power sources 1A and 1B that generate alternating current, an inverter is unnecessary, and the alternating current generator of these power generators is connected to the low voltage system 3.

  When there is a synchronous generator having a voltage maintaining capability among the distributed power sources that generate alternating current, the distributed power source can be the master distributed power source 1A. That is, when the synchronous generator is a fuel input type and the output can be controlled, the low-voltage system management device 8 uses the load amount of the low-voltage system 3 (the power used by all the consumers 2A, 2B, 2C connected to the low-voltage system 3). Since the total amount) is constantly monitored, the low-voltage system management device 8 commands the power generation amount of the synchronous generator in accordance with the load amount. Short-time imbalance between the power generation amount and the load amount due to control delay or the like is absorbed by the power storage device 10. When a plurality of distributed power sources that generate voltage are capable of maintaining voltage and are connected to the low-voltage system 3, a master distributed power source 1A having a larger capacity or that can be easily controlled is used. Is desirable.

  In addition, when the distributed power source that generates alternating current is an induction generator having no voltage maintaining capability, the distributed power source is basically the distributed power source 1B of the slave consumer 2B. However, when there is no other distributed power source that can be the master distributed power source 1A, the AC output of the distributed power source is converted into direct current by an inverter and then connected to the AC power source to connect the distributed power source to the master distributed power source 1A. It is possible to

  Further, in the above description, the consumer who receives the supply of surplus power is only the consumer 2C that does not have the distributed power source. However, if the consumer 2B having the distributed power source 1B has a power shortage, the demand is You may make it supply surplus electric power also to the house 2B. In other words, in the above description, when the customer 2B having the distributed power source 1B runs out of power, that is, when the “load usage” is larger than the “power generation amount of the distributed power source”, the switch 11 is opened. However, in this case, the switch 11 may be closed to receive surplus power. In this case as well, surplus power can be used effectively.

(1) In order to verify the effectiveness of the self-sustaining operation method and the self-sustaining operation system of the low-voltage system of the present invention, a verification test was conducted. This self-sustained operation method and self-sustained operation system is applied in the demand area system assuming that many distributed power sources are connected to the customer side. In addition, the demonstration test of the autonomous operation of the low-voltage system is also explained.

(2) Overview of Supply / Demand Interface (Customer Management Device 6) (2.1) An overview of the supply / demand interface will be described.
The supply-demand interface (supply-demand IF) is a system that performs ancillary service and energy management for consumers in a demand area system. The concept of the supply and demand interface is shown in FIG.

  As shown in FIG. 6, the supply and demand interface receives the charge system information from the demand point system, controls the distributed power source and home appliances that it owns, and feeds back the operating status of the distributed power source and the power consumption of the load to the system side. . The supply-demand interface expresses various elements in the customer premises in the form of objects such as power meter objects, distribution board objects, home appliance objects, distributed power supply objects, sensor objects, and information terminal objects. Protects consumers such as overcurrent detection, automatic operation and load control of home appliances, coordinated operation and interconnection protection of distributed power sources, and power quality monitoring.

(2.2) Next, the supply and demand interface system pilot system will be described.
A supply / demand interface pilot system was installed to verify the function of the supply / demand interface in the previous section. An outline of the pilot system is shown in FIG.

  The pilot system includes a low-voltage system management system (low-voltage system management device 8) that manages the low-voltage system, a low-voltage switch that shuts off the low-voltage system from the high-voltage system in the event of an accident, a low-voltage simulated distribution line that simulates the impedance of the low-voltage trunk line and branch line, And 4 simulated customers. Each simulated customer is a semiconductor switch that disconnects and reconnects without interruption, a consumer power conditioner with advanced inverter functions, a distributed power source (solar power generation: rated 4.5 kW), a distributed type A storage battery (capacity 1 kWh) for smoothing power output and absorbing load fluctuations, an electronic load device (rated 6 kVA) for simulating a consumer, and a supply / demand interface for controlling them. Communication between the supply and demand interface and the customer power conditioner is RS232, between the supply and demand interface and the electronic load is RS232 via Ethernet (registered trademark), and between the supply and demand interface and the low-voltage system management system is Ethernet (registered trademark). .

  The low-voltage system management system performs operation management of the low-voltage system under the pole transformer based on information from the operation management subsystem (operation management sub-device 13) and the low-voltage supply and demand interface. In the event of a low-voltage system accident, the low-voltage switch is opened to prevent the accident from spreading to the high-voltage system, which is the host system (hereinafter referred to as the host system), and to give instructions to each customer's supply and demand interface. Implement autonomous operation. In addition, if an abnormality occurs in the high-voltage system, which is the upper system, the low-voltage system switch is opened based on information measured by the low-voltage system management system itself or information from the operation management subsystem. Perform autonomous operation. The self-sustained operation of the low-voltage system will be described in detail in section (5) below.

  In addition, the low-voltage system management system constantly monitors the voltage and current of the low-voltage system based on information from the supply-demand interface, and implements the active power / power factor command and load control of the distributed power supply to the supply-demand IF when the system is abnormal To do. Further, according to a request from the operation management subsystem, the load state of the low-voltage system and the distributed power supply operation status are collected and notified to the operation management subsystem.

  As an example of the functions, examples of display screens of the low-voltage system management system are shown in FIGS. The upper part of FIG. 8 shows the state of the low-voltage system switch (circle numeral 1) and the state of the low-voltage system (circle numeral 2). When the upper system is abnormal, the abnormality occurrence time and system information at that time are displayed and the low-voltage switch is tripped to notify the lower-level supply and demand interface of the system abnormality. In addition, manual low-voltage system independence and interconnection return are possible.

  The lower part of FIG. 8 shows the state of each consumer power conditioner. By constantly communicating with the supply and demand interface and the customer's power conditioner, it is possible to grasp the setting value and operating state of the consumer's power conditioner, storage battery voltage / current, DC input voltage / current, AC input / output current / voltage, etc. Number 3). In addition, load fluctuation compensation and reactive power / harmonic compensation function of a consumer power conditioner can be turned on / off, and a power factor command and an output suppression command can be issued when voltage rise is suppressed (circled number 4).

  FIG. 9 shows the state of the low-voltage system. Voltage / current / active / reactive power and zero-phase current (circle number 1) of each phase of low-voltage system, connection point voltage / current / active power / reactive power of each customer, load active power / reactive power and dispersion Type power supply active power / reactive power (calculated value) (circled number 2) is always displayed. In addition, the voltage rise suppression prevention function (circled number 3) at the time of reverse power flow of the distributed power supply can be activated from this screen.

(3) Development of customer simulator (3.1) The outline of the customer simulator will be described.
The consumer simulator virtually reproduces the usage status of electrical devices in the home on a computer, calculates the load power in the home according to the ON / OFF state of each device, and instructs the electronic load on the calculation result. Thus, the load electric energy in the home is reproduced in real time.

(3.2) A method for expressing a device will be described.
Each home appliance in the simulator is expressed in the form of a home appliance object, and in addition to the device name, state, rated power, power consumption, power factor, connection circuit, connection phase, installation location, device classification, standby power consumption, consumption It has elements of power fluctuation and control priority. In addition to these, two spare elements are prepared.

  Among the elements, the device name, rated power, standby power consumption, and device classification are fixed, and the connection phase and installation location are fixed except for mobile devices such as vacuum cleaners and irons. For mobile devices, the connection phase, connection circuit, and installation location are automatically recognized when connected to a room outlet. The power consumption, power factor, and operating state vary depending on the state of the device. The power consumption fluctuation degree is an index indicating how much the output of each device fluctuates, and is calculated by dividing the variance of the power consumption amount during device operation by an average. For example, a device such as a refrigerator that repeatedly turns on and off has a large value, and conversely, a device such as a lighting device becomes small.

  In this series of demonstration experiments, provisional values were entered. The control priority is input by the customer as an index indicating the priority when the load selection is cut off.

(3.3) Explain the function of the simulator.
The simulator has the following functions: status display of each device, distribution panel status display (voltage, current, contract capacity, branch circuit current, control status), selective load control in branch circuit units, when contract capacity is exceeded Selection load control, load selection cutoff by emergency load control, and selection load control during autonomous operation.

  In this series of demonstration tests, 3LDK customers were assumed, and the details of the equipment objects of each customer were assumed as shown in Table 1. Table 1 is a list of devices assumed by the consumer simulator. Examples of the status display screen of each device, the screen of the distribution board, and the screen under control are shown in FIGS.

Device status display FIG. 10 is a device status display screen. The operation / stop state can be switched by double-clicking each device in the figure. As shown in the lower left display explanation, the operating device is displayed in light blue, and the stopped device is displayed in white. Also, the load selection cutoff control target device is displayed in pink. Equipment in each room other than large-capacity equipment such as air conditioners and electric water heaters supplied by a dedicated circuit shall be connected to the branch circuit supplying the room, and in each room such as a vacuum cleaner or iron A mobile device that may be used is connected to a branch circuit of the room by drag-and-drop on the room to be used.

・ Distribution panel display The distribution panel display (Fig. 11) displays the passing current of each branch circuit, the passing current of the main trunk, the contract capacity, etc., as in the device display, blue when energized, white when disconnected During control, it is displayed in pink. During control, the control target device and the branch circuit to which the device is connected are displayed on the hop-up screen.

・ Screen during control An example of the screen during control is shown in FIG. In this example, the living room air conditioner connected to the branch circuit 6 dedicated to the air conditioner is the control target. Similarly to the screen at the time of control, the control release device and the branch circuit to which the device is connected are displayed on the hop-up screen.

<Connection circuit>:
1: living room, 2: kitchen, 3: Japanese-style room, bedroom, 4: corridor, bathroom, washroom, toilet, 5: spare A, 6-8: dedicated to air conditioner, 9: dedicated to water heater, 10: spare, 99: undefined (Mobile equipment)
"Installation location":
1: Living room, 2: Kitchen, 3: Japanese-style room, 4: Bedroom, 5: Entrance / hallway, 6: Bathroom, 7: Toilet, 8: Toilet, 99: Indefinite (mobile equipment)
<< Connection Phase >>
1: U-N (100 V), 2: V-N (100 V), 3: U-V (200 V), 99: Indefinite (mobile equipment)
<Classification>:
1: Information, 2: Lighting, 3: Sanitation, 4: Kitchen, 5: Hot water supply, 6: Entertainment, 7: Air conditioning / ventilation, 99: Other

(4) Load selection cutoff function (load selection cutoff operation)
The load selection cut-off function is a function that gradually cuts off the customer equipment based on a predetermined rule to prevent a branch circuit from being cut off or an indoor stop. This function can be divided into selective interruption at all times, emergency, and independence.

(4.1) The constant load selection cutoff will be described.
In the normal load selection cutoff, the supply / demand interface monitors the current passing through the main and branch circuits, and when the capacity is exceeded, the load is selectively cut off based on a predetermined priority order. In addition to this, current monitoring is performed for each branch circuit unit and control is performed when the capacity is exceeded.

  The capacity excess determination is based on the time characteristics of the breaker, and is determined to exceed the capacity when a current 1.1 times the rated current continues for 30 seconds. If the excess capacity is not resolved after the load is cut off, the next device to be controlled is cut off. In order to monitor overcapacity elimination by devices with intermittently changing current values, such as refrigerators and air conditioners, the controlled device is restored after a certain period of time, but it has been controlled three times in succession to prevent control hunting. The device is locked in the control state without performing recovery operation thereafter.

  The priority of control is as shown in FIG.

  In the demonstration test, it was prohibited to move to the next control operation for 30 seconds in consideration of the control delay due to the communication time delay between the supply and demand interface and the inverter and the electronic load.

(4.2) Explain emergency load selection interruption.
In the emergency load selection interruption, the customer autonomously controls the load by temporarily reducing the contract current based on the load control request from the operation management system when the system is tight. A load control request amount is sent from the operation management system, and the supply and demand interface changes the current contract power to the contract power for emergency in consideration of the current load state and load reduction possible amount, and based on the changed contract capacity To selectively shut off the load. Since the control logic is the same as that at all times, it does not require a new load control logic.

  The load control is released by a release command from the operation management system, and the normal mode is restored.

(4.3) Independent load selection cutoff (step S58 in FIG. 4, etc., step S67 in FIG. 5, etc.) will be described.
The load selection cutoff function at the time of self-supporting selectively cuts off loads other than the critical load according to the power available to the storage battery and the power that can be output from the distributed power source during the independent operation of the customer premises when the host system is abnormal. To sustain the supply of

  In this case, it is necessary to accurately grasp the battery usable power. Charge / discharge control as shown in Table 2 is given to the storage battery of the consumer power conditioner. Table 2 is a table showing a method for limiting charging and discharging of the storage battery.

  During self-sustained operation, storage battery degradation due to overdischarge becomes a problem. Therefore, the power that can be used is 100% when the upper limit value of the storage battery voltage is not limited, and the battery that can be used is 0% when the discharge is stopped. It was assumed that the available power during that time was given as a linear function of the battery voltage and decreased linearly.

That is, Equation 1 to Equation 3 are given where Batrem is the power available for battery use and Vbat is the storage battery voltage. Further, FIG. 14 shows the relationship between the storage battery voltage and the available battery power.
・ When Vbat ≧ 247.2 [V] [Equation 1]
Batrem = 3000 [W] (3000W: Inverter rating for self-supporting)
・ When Vbat <198 [V] [Equation 2]
Batrem = 0 [W]
・ When 198.0 ≦ Vbat <247.2 [V]

  Next, the relationship between load supply, distributed power output, and storage battery charge / discharge during self-sustained operation in the supply and demand interface pilot system will be described.

  When the load Pload (i), storage battery charge / discharge PBat (i), and photovoltaic power generation output PPV (i) of each customer i at the time of the interconnection operation, the interconnection point output Pgc (i) is expressed by Equation 4. The

[Equation 4]
Pgc (i) = Pload (i) + PBat (i) −PPV (i)
(However, discharging with PBat <0, charging with PBat> 0)
(During reverse power flow (Pgc (i) <0), PBat (i) = 0)

  Pgc (i) = 0 at the time of independence, but the consumer power conditioner sets the AC output voltage to 200 V and changes the DC side power according to the load current. When the load power is larger than the distributed power (solar power) generated power, that is, when PPV (i)> Pload (i), Equation 5 is obtained, and the shortage of the distributed power generation is discharged from the storage battery.

[Equation 5]
Pload (i) = PPV (i) -PBat (i)

  On the other hand, when the solar cell output is larger than the load output, that is, when PPV (i)> Pload (i), the surplus storage battery is not charged and PPV (i) = Pload (i) The solar power output is suppressed so that Therefore, if load control is performed during the self-sustained operation, only the power generation amount for the controlled load can be obtained even if the output of the distributed power source is recovered, and thus the power generation amount remains suppressed.

  From the above, it is necessary to estimate the output power (PPVpot) in order to effectively use the output of the distributed power source during self-sustainment. A distributed power source that can control the output of a gas engine, etc. can output the rated power as it is, but the output of solar power generation changes with the intensity of solar radiation, so the output power (PPVpot) uses the intensity of solar radiation (PVIns) Estimated.

In the estimation, it was estimated as Equation 6 using the linear regression from the past measured output value and the measured solar radiation intensity (see FIG. 15).
[Equation 6]
PPVpot = 3684 x PVIns -184
However, PPVpot = 0 when PVIns <0.05 kW / m2.

The available power (Wavail) is calculated by the sum of these (Formula 7).
[Equation 7]
Wavail = PPVpot + Batrem
However, when PPVpot + Batrem> 3000W, Wavail = 3000.

FIG. 16 shows the flow of the self-supporting load selection cutoff function.
This time, the supply and demand interface decided the control equipment according to the predetermined control order.

(4.4) Explain the verification test.
In order to verify the effectiveness of the proposed function, a demonstration test of load selection interruption was conducted. The initial setting of the load of each consumer was selected from the device setting table of Table 1 so that the load rating of each inverter was (3 kVA) and was 3000 W or less. Table 3 shows the selected devices. Table 3 is a list of devices assumed in the load selection interruption test at the time of independent operation on the customer premises.

  During the test, the low-voltage system was shut off from the host system with a low-voltage switch, and each customer was shifted to independent operation. Each supply-and-demand interface performs selective load control based on the priority shown in FIG. 13 according to the available power expressed by Equation 5. In the demonstration test, the electronic load was stopped when the storage battery voltage became 190 V or less in order to protect the storage battery. As a case where load selection interruption is not performed, the electronic load output at the start of operation is continued, and compared with a case where the electronic load is stopped when the storage battery voltage is similarly 190 V or less. In order to suppress changes due to the remaining amount of the storage battery as much as possible, the storage battery was started in an evenly charged state (SOC 50%).

  As the storage battery voltage, a value notified from each power conditioner to the supply and demand IF was used. In terms of solar radiation intensity, the inclined surface solar radiation meter is installed only on the solar panel of customer # 2, but all of the photovoltaic power generation facilities of the demonstration test equipment have the same rated output and the installation locations are very close. Therefore, the solar output of other customers was estimated using the solar radiation meter data of customer # 2. As an example, FIG. 17 and FIG. 18 show experimental results when there is no distributed power source.

  FIG. 18 shows that the load is selectively cut off as the storage battery voltage decreases. It can also be seen that when a device with a large capacity is shut off, the storage battery voltage recovers and the controlled load is released. In the case of no control, the time that can be supplied by only the storage battery was 14 minutes, but this load selection cutoff enabled the extension to about 4 times 54 minutes.

  Next, FIG. 19 shows a selective interruption state of a customer's load. As shown in FIG. 19, an example in which a lighting device with a small capacity causes hunting as the storage battery voltage recovers. As means for preventing this, it is necessary to devise devices such as grouping devices with small capacities and setting a dead zone at the time of control release determination. In addition, when the power outage time is known in advance due to a construction power outage or the like, a service such as estimation of the supplyable time according to the load from the remaining amount of the storage battery can be considered.

  In the case with a distributed power source, load control was not performed when the solar cell output during the day was large, and the load was supplied from photovoltaic power generation. Thereafter, when the amount of solar radiation decreased, the load selection cut-off was performed, so that the supply duration time was changed from 322 minutes to 347 minutes.

(5) Low voltage system autonomous operation (5.1) The purpose of the low voltage system autonomous operation will be explained.
Currently, when a high-voltage system fails, a customer who owns a distributed power source temporarily disconnects the distributed power source to prevent isolated operation and connects the load to a self-supporting circuit as necessary. Supply to At this time, since the distributed power source is operated according to the load, the generated power is wasted if the load is lower than the generated power. In addition, a consumer who does not have a storage battery cannot use a load more than the generated power. In addition, the non-distributed power supply non-owned customers continue to be suspended until the upper system is restored.

  In order to solve these problems, a self-sustaining operation function of the low voltage system was devised in the demand area system.

(5.2) An outline of the low-voltage system independent operation will be described.
In the low voltage system independent operation, when the upper system is abnormal, the entire low voltage bank is disconnected from the upper system, one of the distributed power supplies connected to the low voltage system maintains the voltage of the entire low voltage system, and the other distributed power supply manages the low voltage system Supply to the low-voltage system is continued by performing coordinated operation in response to a command from the system. The concept is shown in FIG. Here, customer # 4 is a non-distributed power source customer, customer # 1 is a customer with a distributed power source that maintains the voltage of the entire low-voltage system and adjusts supply and demand, and customer # 2 and # 3 Other customers with distributed power sources.

(A) Customer # 1
Customer # 1 is a consumer who owns a distributed power source capable of maintaining the voltage of the low-voltage system, and adjusts the load balance in the low-voltage system by adjusting the output of the distributed power source and charging / discharging the storage battery. The distributed power source of customer # 1 is preferably a power source with a relatively large capacity and output control, such as a gas engine or a micro gas turbine. Load fluctuations that cannot be fully responded at the output change rate of the distributed power supply are covered by charging and discharging of the storage battery.

(B) Customer # 2, # 3
Customers # 2 and # 3 perform a grid operation when the distributed power output is larger than the load, that is, when reverse power flow is possible (customer # 3), according to a command from the low-voltage system management system. Do load accommodation at home. When the load is smaller than the distributed power output (customer # 2), the operation shifts to the customer premises independent operation.

(C) Customer # 4 (no distributed power supply)
Customer # 4 is a non-distributed power supply customer who is currently out of supply at the time of a power outage. However, in the demand system, load can be supplied according to the distributed power generation surplus capacity owned by other customers. The low-voltage system management system calculates the decentralized power supply capacity and notifies each customer of the amount of power that can be supplied. When the distributed power generation surplus capacity is zero, all but the necessary minimum critical load is shut off.

  By performing the control as described above, it is possible to effectively use the distributed power output, and to continue supplying to customers who do not own the distributed power supply.

  The low-voltage system autonomous operation is shifted to either the upper system abnormality detection of the low-voltage system management system or the independent operation command from the operation management subsystem. System reconnection from autonomous operation is performed by a command from the operation management subsystem. During grid reconnection, when load fluctuation compensation and distributed power fluctuation compensation mode are ON, grid reconnection occurs when the grid connection point power is zero, and the output gradually changes. The shock is small.

(5.3) Demonstrate the verification test of the low voltage system independent operation.
In order to verify the effectiveness of the developed low-voltage system autonomous operation, a verification test was conducted. In this demonstration test, a distributed power source that can adjust the output and supply voltage to the low-voltage system is not equipped in the demand-source system hybrid demonstration test facility, so it is one of four customer power conditioners. The base (PCS # 1) was used as a base unit, electronic loads # 1 and PCS # 2 to # 4 were connected to the load side, and electronic loads # 2 to 4 were connected to the load sides of PCS # 2 to # 4. In addition, the DC input side of # 4 PCS was cut off to make it a non-distributed power supply consumer. As the distributed power source, an actual solar panel was used. A test circuit is shown in FIG.

  The initial setting of the load of each consumer is based on the equipment setting table of Table 1 so that it is about 600 W in consideration of the independent load rating (3 kVA) of power conditioner # 1 and the power consumption of each power conditioner. Selected. The selected loads are shown in Table 4. Table 4 is a list of devices assumed in the load selection interruption test at the time of low voltage system independent operation.

  In the above circuit, the voltage was cut off at the upper side of the low-voltage switch, and the low-voltage system was shifted to the self-sustaining operation mode. The behavior at the time of transition to independent operation is shown in FIGS.

  FIG. 22 shows the situation before the transition to independence. The arrows in the figure indicate the direction of the tidal current. Immediately before the transition to independence, the distributed power output is excessive, and customers # 2 and # 3 are in reverse flow, supplying surplus to customer # 4 and combining with surplus power from customer # 1. Reverse power flow is performed on the low-voltage system side.

  From this state, supply to the low-voltage system is shut off. The power conditioner of customer # 1 detects a system voltage drop and shifts to the self-sustaining operation mode without interruption (within 2 cycles) (circle numeral 1 in FIG. 23). The low-voltage system management system detects a system abnormality after about 0.5 seconds, opens the low-voltage switch (circled number 2), and notifies the system abnormality signal to the demand / supply interface of the customers # 1 to # 4. About 1 second after receiving the inverter, each inverter will shift to in-house self-supporting (circle number 3).

  After that, the customers # 2 and # 3 calculate the predicted interconnection point power Pgcpot (i) shown in Equation 8 (circled number 4 in FIG. 24), and if Pgcpot (i)> 0, Perform system (circle number 5). Customer # 4 performs re-connection to the grid (circle numeral 8) after the load is cut off (circle numerals 6, 7).

[Equation 8]
Pgcpot (i) = Pload (i) −PPVpot (i)

  The low-voltage system management system calculates the distributed power remaining capacity (LVpot) expressed by Equation 9, and when there is sufficient capacity (circled number 9 in FIG. 25), cancels the load cut of the customer # 4. (Circle number 10). On the contrary, when the remaining power becomes small due to the decrease in the amount of solar radiation (circle numeral 11 in FIG. 26), the load is cut off (circle numeral 12).

[Equation 9]
LVpot = ΣPgcpot (i)
(However, Pgcpot (i) <0 for consumers with Pgcpot (i) = 0)

  When the amount of solar radiation further decreases and Pgc (i) <0 (circled number 13 in FIG. 27), the customers # 2 and # 3 shift to the on-site independent operation (circled number 14). After shifting to independent operation, the load selection interruption described in Chapter (4) is performed.

  As an example of the results of the demonstration test, the connection point effective power, the distributed power output, the storage battery charging / discharging power, the load power, and the low-voltage system power calculated by Equation 10 after the independent transition are shown in FIG. 32.

  In FIG. 28, since the distributed power remaining capacity has decreased around 3 minutes, customer # 4 is blocking loads other than the important load (corresponding to FIG. 26). Thereafter, the solar radiation amount recovered around 15 minutes, and the distributed power supply remaining capacity decreased, so that the load control is canceled (corresponding to FIG. 25).

  Around 24 minutes, the reverse power flow of the customers # 2 and # 3 increased, so the apparent load of the low-voltage system decreased (see FIG. 32), and the distributed power output of the customer # 1 is suppressed. . Since solar radiation decreased again around 27 minutes, customer # 4 performed load control again. At this time, the discharge amount of the storage battery of the customer # 1 is increasing due to the control delay (FIG. 30). After that, the amount of solar radiation decreased further, and the connecting point power of the consumers # 2 and # 3 changed from the reverse power flow to the forward power flow, so that the customers # 2 and # 3 have shifted to the on-site independent operation (FIG. 27). Equivalent).

  Thereafter, the supply was continued until the storage battery capacity was exhausted by the load selection interruption described in Chapter (4).

  As described above, by operating the low-voltage system autonomously, if there is a margin in the amount of power generated by the distributed power supply, it is possible to reconnect to allow the surplus to be supplied to the low-voltage system and effectively use the distributed power output At the same time, it has been confirmed that non-distributed power supply owners can continue to supply.

It is a conceptual diagram which shows an example of embodiment of the self-sustained operation system of the low voltage | pressure system of this invention. It is a flowchart which shows the operation | movement procedure of a low voltage | pressure system management apparatus. It is a flowchart which shows the operation | movement procedure of the supply-demand IF of a master consumer. It is a flowchart which shows the operation | movement procedure of the demand / supply IF of a slave customer. It is a flowchart which shows the operation | movement procedure of the demand-and-supply IF of the consumer who does not have a distributed power supply. It is a figure which shows the function and structure of a supply-and-demand interface. It is a schematic block diagram which shows a supply-and-demand interface pilot system. It is a figure which shows the main screen of a low voltage | pressure system management system. It is a figure which shows the low voltage | pressure system information display screen of a low voltage | pressure system management system. It is a figure which shows an apparatus status display screen. It is a figure which shows a distribution board screen. It is a figure which shows an example of the screen during control. It is a figure which shows the priority of control. It is a figure which shows the relationship between a storage battery voltage and battery use electric power possible electric power. It is a figure which shows the output estimation of solar power generation. It is a figure which shows the flow of the load selection interruption | blocking function at the time of self-supporting. It is a figure which shows a load selection interruption | blocking result (no distributed power supply). It is a figure which shows transition of the storage battery voltage at the time of load selection interruption | blocking. It is a figure which shows the selection interruption | blocking condition. It is a conceptual diagram of a low voltage | pressure system independent operation. It is a figure which shows a low voltage | pressure system independent operation test circuit. It is a figure which shows the state before independent operation transfer. It is a figure which shows the state after independent operation transfer. It is the figure of the state which shows the state after independent operation transfer, and follows FIG. It is a figure of the state which shows the state after independent operation transfer and continues from FIG. It is a figure of the state which shows the state after independent operation transfer and follows FIG. FIG. 27 is a diagram illustrating a state after transition to a self-sustained operation and a state following FIG. 26. It is a figure which shows connection point active power. It is a figure which shows a distributed power output. It is a figure which shows storage battery charging / discharging electric power. It is a figure which shows load electric power. It is a figure which shows a low voltage | pressure system electric power.

Explanation of symbols

1A Master distributed power source 1B Distributed power sources 2A and 2B other than the master distributed power source 2C Consumer 2C having distributed power source 3 Low power system 4 High voltage system 5 Switch 6 Supply / demand IF

Claims (5)

  A power supply is supplied to a plurality of consumers including at least one customer having a distributed power source, and the low-voltage system in which the distributed power source is connected to the grid is connected to the high-voltage system in the event of an abnormality in a high-voltage system that is a higher system. The voltage of the low-voltage system is maintained by one of the distributed power sources that are grid-connected to the low-voltage system, the excess or deficiency of power is calculated for each consumer, A self-sustaining operation method for a low-voltage system, characterized in that surplus power is supplied to a consumer with insufficient power.   2. The self-sustained operation method for a low-voltage system according to claim 1, wherein a load fluctuation of the low-voltage system that cannot fully respond at an output change rate of a distributed power source that maintains the voltage of the low-voltage system is covered by charging and discharging of a power storage device. .   For customers who do not have a distributed power source, if the power is still insufficient even after receiving surplus power, the load should be shut down in order of decreasing priority until the power shortage is resolved. 3. The self-sustaining operation method for a low-pressure system according to claim 1 or 2.   Regarding a customer having a distributed power source, in the case of power shortage, the customer is disconnected from the low-voltage system, and loads are cut off in order of decreasing priority until the power shortage is resolved. Item 4. The self-sustaining operation method for a low-pressure system according to any one of Items 1 to 3.   In a self-sustained operation system of a low-voltage system in which a customer having a distributed power source and a customer not having a distributed power source are connected to each other, the low-voltage system is separated from the high-voltage system when an abnormality occurs in the high-voltage system that is a higher-level system. And a master distributed power source that maintains the voltage of the low-voltage system when the low-voltage system is separated from the high-voltage system, and an excess of power in the consumer provided for each consumer. A consumer management device that calculates a shortage, and the consumer management device of a consumer having a distributed power source other than the master distributed power source supplies the customer's distributed power source to the low-voltage system when surplus power is generated In addition, the low-voltage system self-sustained operation system is characterized in that when the surplus power is not generated, the consumer is disconnected from the low-voltage system.