WO2014020644A1

WO2014020644A1 - Power supply system, master power storage system, and slave power storage system

Info

Publication number: WO2014020644A1
Application number: PCT/JP2012/004875
Authority: WO
Inventors: 久保　守
Original assignee: 三洋電機株式会社
Priority date: 2012-07-31
Filing date: 2012-07-31
Publication date: 2014-02-06
Also published as: JPWO2014020644A1

Abstract

This power supply system is equipped with: a master power storage system (10a) for supplying an alternating current having predetermined voltage and frequency to a load (71); at least one slave power storage system (10b) for supplying an alternating current to the load (71) on the basis of an instruction from the master power storage system (10a); current detectors for detecting the currents supplied from the master power storage system (10a) and the slave power storage system (10b) to the load (71); and a voltage detector for detecting an output voltage and an output frequency of the master power storage system (10a). A control unit of the master power storage system (10a) indicates, to a control unit (15b) of the slave power storage system (10b), a value of current to be supplied to the load (71) by the slave power storage system (10b) on the basis of the current values detected by the current detectors.

Description

Power supply system, master power storage system and slave power storage system

The present invention relates to a power supply system including a storage battery, a master power storage system, and a slave power storage system.

Storage systems with storage batteries and bidirectional inverters have become widespread. The power storage system is connected to the grid and used for backup and peak shift in the event of a power failure. There are various types of power storage systems ranging from small to large.

JP 2000-287360 A

When adding another power storage system to an existing power storage system or when introducing multiple small or medium power storage systems in a large-scale facility, it may be necessary to operate the plurality of power storage systems in a coordinated manner. . For example, when a load capacity exceeding the rated output capacity of each power storage system occurs, it is necessary to operate a plurality of power storage systems in cooperation.

The present invention has been made in view of such a situation, and an object thereof is to provide a technique for efficiently operating a plurality of power storage systems in a coordinated manner.

A power supply system according to an aspect of the present invention includes a master power storage system that supplies an alternating current having a predetermined voltage and frequency to a load, and at least one that supplies the alternating current to the load based on an instruction from the master power storage system. A slave power storage system; a current detector that detects current supplied from the master power storage system and the slave power storage system to the load; and a voltage detector that detects an output voltage and an output frequency of the master power storage system. The master power storage system and the slave power storage system include a storage battery, a power converter disposed between the storage battery and the load, and a control unit that controls each power storage system, and are parallel to the load. It is connected. The control unit of the master power storage system instructs the control unit of the slave power storage system to supply a current value to be supplied to the load based on the current value detected by the current detector. The control unit of the slave power storage system supplies the load with a current value instructed from the master power storage system at the output voltage and the output frequency detected by the voltage detector.

According to the present invention, a plurality of power storage systems can be efficiently operated in cooperation.

It is a figure which shows the structure of the power distribution system which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the 1st electrical storage system and the 2nd electrical storage system which are included in the power distribution system which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the 1st control part which concerns on Embodiment 1 of this invention, and a 2nd control part. It is a flowchart for demonstrating operation | movement of the power distribution system which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the power distribution system which concerns on Embodiment 2 of this invention. It is a flowchart for demonstrating operation | movement of the power distribution system which concerns on Embodiment 2 of this invention. It is a flowchart for demonstrating operation | movement of the power distribution system which concerns on Embodiment 3 of this invention. It is a figure which shows the structure of the power distribution system which concerns on Embodiment 4 of this invention. It is a figure which shows the structure of the 1st control part which concerns on Embodiment 4 of this invention, and a 2nd control part. FIGS. 10A and 10B are flowcharts for explaining the operation of the power distribution system according to the fourth embodiment of the present invention. It is a figure which shows the structure of the 1st control part which concerns on the modification 2, and a 2nd control part. 10 is a flowchart for explaining a master setting process according to a second modification.

Embodiment of this invention is related with the power distribution system which connects a solar cell in parallel with a commercial power system, supplies electric power to a load from both a commercial power source and a solar cell, and charges a storage battery. Such a power distribution system is suitable for installation in commercial facilities, public facilities, office buildings, condominiums, and the like. When the electric power company adopts the electricity bill system by time zone, the electricity bill at night time is set lower than the electricity bill at daytime. As an example of these time zones, the daytime time zone is defined as 7 o'clock to 23:00, and the night time zone is defined as 23 o'clock to 7 o'clock on the next day. In order to effectively use such a low electricity bill, the power distribution system stores power in the storage battery with electric power from a commercial power source in the night time zone.

The electric power stored in the storage battery is used as a backup power source for operating important devices such as elevators and servers when the commercial power supply fails. Furthermore, the storage battery is generally used as a so-called peak shift that lowers the maximum value of the amount of use in commercial power during the daytime by discharging in the daytime hours when the amount of use of electricity is large.

Thus, the storage battery has two roles: a role as a backup for a specific load and a role as a peak shift. In the power distribution system according to the embodiment, in order to cause the storage battery to perform the above-described two roles, the commercial power supply performs a peak shift while securing a certain amount of power storage in the storage battery at normal times when the commercial power supply is energized. In the case of a power failure, the storage battery is discharged to supply power to a specific load.

FIG. 1 is a diagram showing a configuration of a power distribution system 50 according to Embodiment 1 of the present invention. The power distribution system 50 according to the first embodiment is a system for supplying power to the load 70. The power distribution system 50 includes a plurality of power storage systems 10, a first detector 20, a second detector 30, a first switch SW1, a second switch SW2, and a distribution board 40. In the example illustrated in FIG. 1, the power distribution system 50 includes the first power storage system 10 a and the second power storage system 10 b as the plurality of power storage systems 10. Three or more power storage systems 10 may be provided.

FIG. 2 is a diagram showing configurations of the first power storage system 10a and the second power storage system 10b included in the power distribution system 50 according to Embodiment 1 of the present invention. In the following description, the first power storage system 10a and the second power storage system 10b are the same power storage system, and the first power storage system 10a is a master and the second power storage system 10b is a slave.

The first power storage system 10a includes a first storage battery 11a, a first bidirectional inverter 12a, a thirteenth switch SW3a, a first solar battery 13a, and a first control device 14a. The first control device 14a includes a first control unit 15a and a first storage battery management unit 16a. Similarly, the second power storage system 10b includes a second storage battery 11b, a second bidirectional inverter 12b, a 23rd switch SW3b, a second solar battery 13b, and a second control device 14b. The second control device 14b includes a second control unit 15b and a second storage battery management unit 16b. The first solar cell 13a and the second solar cell 13b are an example of a renewable energy power generator.

Hereinafter, the power distribution system 50 according to the first embodiment will be described in detail with reference to FIGS. 1 and 2. The load 70 is classified into a first type load 71 and a second type load 72. Both are devices driven by AC power. The first type load 71 is a predetermined specific load that can be preferentially received from the first storage battery 11a and the second storage battery 11b during a power failure. For example, elevators and servers are applicable. The second type load 72 is a general load. The second type load 72 basically cannot receive backup power from the first storage battery 11a and the second storage battery 11b during a power failure. By giving priority to the load 70 in this way, it is possible to effectively use the limited power stored in the storage battery at the time of a power failure.

Commercial power supply 60 is a system power supply supplied from an electric power company. The distribution board 40 is connected to the system and is connected to the first bidirectional inverter 12a and the second bidirectional inverter 12b via the first switch SW1. More specifically, the AC side terminal of the first bidirectional inverter 12a is connected to the first node N1 to which the AC side terminal of the second bidirectional inverter 12b is coupled.

Distribution board 40 supplies AC power drawn from the system to load 70 on the premises. In addition, the distribution board 40 is connected to the generated power from the first solar battery 13a or the second solar battery 13b, the first storage battery 11a or the second storage battery 11b via the first bidirectional inverter 12a or the second bidirectional inverter 12b. Receive discharge power, or any combined power thereof. The distribution board 40 can also synthesize the power and the power from the grid and supply them to the load 70.

The first switch SW1 is provided between the distribution board 40 and the first node N1. The second switch SW2 connects the connection destination of the input terminal of the first type load 71 to the second node N2 between the distribution board 40 and the first switch SW1, or between the first node N1 and the first switch SW1. Or switch to the third node N3. The first switch SW1 and the second switch SW2 are controlled by the first controller 15a.

When only the system power is supplied to the load 70, the first control unit 15a controls the first switch SW1 to be off and connects the second switch SW2 to the second node N2 side. When the grid power and the power from the first power storage system 10a and / or the second power storage system 10b are combined and supplied to the load 70, the first control unit 15a controls the first switch SW1 to be on and the second switch SW2 is connected to the second node N2 side. At the time of a power failure, the first control unit 15a controls the first switch SW1 to turn off and connects the second switch SW2 to the third node N3 side.

The first solar cell 13a and the second solar cell 13b are power generation devices that directly convert light energy into electric power using the photovoltaic effect. As the first solar cell 13a and the second solar cell 13b, a silicon solar cell, a solar cell using various compound semiconductors, a dye-sensitized type (organic solar cell), or the like is used. The first solar cell 13a is connected to a fourteenth node N4a between the first bidirectional inverter 12a and the first storage battery 11a via a thirteenth switch SW3a. The second solar cell 13b is connected to the 24th node N4b between the second bidirectional inverter 12b and the second storage battery 11b via the 23rd switch SW3b.

The first bidirectional inverter 12a and the second bidirectional inverter 12b convert alternating current power input from the alternating current side terminal into direct current power and output the direct current power to the direct current side terminal, and also convert direct current power input from the direct current side terminal to alternating current. Convert to electric power and output to AC side terminal. The AC power input to the AC side terminals of the first bidirectional inverter 12a and the second bidirectional inverter 12b is supplied from the commercial power supply 60. The DC power input to the DC side terminal of the first bidirectional inverter 12a is supplied from the first storage battery 11a or the first solar battery 13a. Similarly, DC power input to the DC side terminal of the second bidirectional inverter 12b is supplied from the second storage battery 11b or the second solar battery 13b.

In the present embodiment, each of the first bidirectional inverter 12a and the second bidirectional inverter 12b is configured by a three-phase AC inverter, and each switching element constituting the three-phase AC inverter is configured by an IGBT (Insulated Gate Gate Bipolar Transistor). The Each three-phase AC inverter is PWM (pulse width modulation) controlled by the first controller 15a and the second controller 15b.

The thirteenth switch SW3a is provided between the first solar cell 13a and the fourteenth node N4a and is controlled by the first control unit 15a. The 23rd switch SW3b is provided between the second solar cell 13b and the 24th node N4b and is controlled by the second control unit 15b. Since the power generation amount of the first solar cell 13a and the second solar cell 13b depends on the amount of sunlight, it is difficult to control the power generation amount. By providing the thirteenth switch SW3a and the twenty-third switch SW3b, it is possible to prevent the first storage battery 11a or the second storage battery 11b from being overcharged by the generated power of the first solar battery 13a or the second solar battery 13b.

The first storage battery 11a and the second storage battery 11b are secondary batteries that can be repeatedly charged and discharged. The first storage battery 11a and the second storage battery 11b are formed, for example, by combining a plurality of battery packs incorporating a large number of lithium ion battery cells. Specifically, a plurality of battery packs are connected in series and parallel, and connected / disconnected by the switching unit in series.

The first storage battery 11a is connected to the 14th node N4a. The first storage battery 11a is basically charged with the system power converted into DC power by the first bidirectional inverter 12a. It is also charged by the power generated by the first solar cell 13a. The first storage battery 11a supplies the load 70 with discharge power converted from DC power to AC power by the first bidirectional inverter 12a. In particular, the power is supplied to the first type load 71 during a power failure.

Each battery pack constituting the first storage battery 11a incorporates a current sensor, a voltage sensor, and a temperature sensor (not shown). Each battery pack constantly monitors the current, voltage, and temperature of each built-in battery cell, and transmits monitoring data to the first storage battery management unit 16a. The first storage battery 11a and the first storage battery management unit 16a are connected by a LAN cable or an RS-232C cable made of an optical fiber, and optically communicate between them. The above description regarding the first storage battery 11a also applies to the second storage battery 11b.

The first detector 20 is provided between the first node N1 and the second node N2. That is, it is provided in a path between the commercial power supply 60 and the first bidirectional inverter 12a and the second bidirectional inverter 12b. The first detector 20 includes a current sensor and a voltage sensor. The 1st detector 20 detects the value of the electric current and voltage supplied to the load 70, and notifies the 1st control part 15a. At the time of a power failure, the current and voltage values supplied to the first type load 71 are detected and notified to the first control unit 15a.

The second detector 30 is provided between the AC terminal of the second bidirectional inverter 12b and the first node N1. The second detector 30 includes a current sensor and a voltage sensor. The second detector 30 detects the value of the current flowing into the first node N1 from the second bidirectional inverter 12b and notifies the second controller 15b. The voltage value of the first node N1 is detected and notified to the second control unit 15b.

The first detector 20 and the first controller 15a are connected by a LAN cable or an RS-232C cable made of an optical fiber, and optically communicated between them. Similarly, the second detector 30 and the second controller 15b are also connected by a LAN cable or an RS-232C cable made of an optical fiber, and optically communicated between them.

Note that it is not necessary for both the first detector 20 and the second detector 30 to include voltage sensors, and either one may be used. In that case, the detector including the voltage sensor notifies the detected voltage value to both the first control unit 15a and the second control unit 15b.

The first storage battery management unit 16a performs charge / discharge control of the first storage battery 11a based on the charge / discharge command and the monitoring data received from the first storage battery 11a. When the charge command is activated, the first storage battery management unit 16a instructs the switching unit of the first storage battery 11a to connect the battery pack and the bus connected to the first bidirectional inverter 12a. At the same time, the first controller 15a is instructed to cause the first bidirectional inverter 12a to perform AC-DC conversion. When the discharge command is issued, the first storage battery management unit 16a instructs the switching unit to connect the battery pack and the bus. At the same time, the first control unit 15a is instructed to cause the first bidirectional inverter 12a to perform DC-AC conversion. The first storage battery management unit 16a and the first control unit 15a are connected by a LAN cable or an RS-232C cable made of an optical fiber, and optically communicate between them. The above description regarding the first storage battery management unit 16a also applies to the second storage battery management unit 16b.

The first storage battery management unit 16a and the second storage battery management unit 16b are connected by a LAN cable or an RS-232C cable made of an optical fiber, and optically communicate between them. Ethernet (registered trademark) can be used for this optical communication. The 1st control part 15a can communicate with the 2nd control part 15b via the 1st storage battery management part 16a and the 2nd storage battery management part 16b.

The first bidirectional inverter 12a and the first control unit 15a constitute a bidirectional power conditioner. Similarly, the second bidirectional inverter 12b and the second control unit 15b also constitute a bidirectional power conditioner. When the commercial power supply 60 is energized, the first bidirectional inverter 12a and the second bidirectional inverter 12b operate at a frequency synchronized with the frequency of the commercial power supply 60 (system linkage operation), and the commercial power supply 60 is in a power failure. Operates at a frequency asynchronous with the frequency of the commercial power source 60 (independent operation).

The first control unit 15a controls the entire power distribution system 50 including the first power storage system 10a and the second power storage system 10b. The second control unit 15b controls the second power storage system 10b. The first controller 15a selects one of the grid interconnection operation mode and the independent operation mode when supplying power to the load 70 from the first solar cell 13a and / or the first storage battery 11a. In the grid connection operation mode, the first solar battery 13a and / or the first storage battery 11a are electrically connected to the commercial power source 60, and the first bidirectional inverter 12a is passing a current synchronized with the commercial power source 60 through the grid. The driving state. The current flowing through this system is a sine wave having the same frequency as that of the commercial power supply 60 and not including a harmonic current exceeding a specified value, and having a power factor of approximately 1 (the same phase as the voltage of the commercial power supply 60). Current.

In the self-sustaining operation mode, the first bidirectional inverter 12a supplies power to the first type load 71 with the first solar cell 13a and / or the first storage battery 11a electrically disconnected from the commercial power source 60. The driving state. In the self-sustained operation mode, the first bidirectional inverter 12a itself generates a sine wave voltage having a prescribed voltage and frequency and having no distortion greater than a prescribed value.

When power is supplied from the first solar cell 13a and / or the first storage battery 11a to the load 70, the first controller 15a operates in the grid connection operation mode when the commercial power source 60 is not out of power. If there is a power failure, operate in autonomous mode. When operating in the grid connection operation mode, the first control unit 15a controls the first switch SW1 to be on, and controls the connection destination of the second switch SW2 to the second node N2 side. At the same time, the phase and frequency synchronized with the commercial power source 60 are set in the first bidirectional inverter 12a so as to be linked to the commercial power source 60. When operating in the independent operation mode, the first control unit 15a controls the first switch SW1 to be turned off, and controls the connection destination of the second switch SW2 to the third node N3 side. At the same time, a phase and frequency independent of the commercial power source 60 are set in the first bidirectional inverter 12a.

The second control unit 15b operates basically in the same manner as the first control unit 15a, but the first switch SW1 and the second switch SW2 are controlled by the master first control unit 15a. The master first control unit 15a controls the cooperative operation of the first power storage system 10a and the second power storage system 10b during a power failure.

FIG. 3 is a diagram showing the configuration of the first control unit 15a and the second control unit 15b according to Embodiment 1 of the present invention. The first control unit 15a of the first power storage system 10a set as the master includes a first drive control unit 151a, a first acquisition unit 152a, a first determination unit 153a, a first current value calculation unit 154a, an instruction unit 155a, a target. A value holding unit 158a is provided. The second power storage system 10b set as a slave includes a second drive control unit 151b, a second acquisition unit 152b, a second current value calculation unit 154b, an instruction reception unit 155b, and a target value calculation unit 158b.

Each configuration of the first control unit 15a and the second control unit 15b can be realized in hardware by an arbitrary microcomputer, memory, or other LSI, and in software by a program loaded in the memory. Although it is realized, here, functional blocks realized by their cooperation are depicted. Accordingly, those skilled in the art will understand that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof.

Note that each component of the first control unit 15a and the second control unit 15b shown in FIG. 3 is necessary for the cooperative operation of the first power storage system 10a and the second power storage system 10b at the time of a power failure, which is noted in this specification. Only the essential components are drawn. Therefore, components for controlling various switches are omitted.

First, the master first control unit 15a will be described. The 1st acquisition part 152a acquires the value of the electric current which flows into the 1st type load 71 from the 1st detector 20 at the time of a power failure. Moreover, the 1st acquisition part 152a acquires the value of the voltage applied to the 1st type load 71 from the 1st detector 20 or the 2nd detector 30 at the time of a power failure.

The target value holding unit 158a holds the voltage and frequency of the AC power to be output from the first bidirectional inverter 12a when performing a self-sustaining operation at the time of a power failure. The target value holding unit 158a may hold a target voltage value at each sampling point for one cycle in a table, or may hold a mathematical formula for calculating the target voltage value. The sampling point is set, for example, every 15 [kHz].

The first drive control unit 151a drives and controls the first bidirectional inverter 12a so that AC power having a preset voltage and frequency is supplied to the system side at the time of a power failure. This voltage and frequency are held in the target value holding unit 158a. In this specification, drive control is performed so that an AC voltage of 200 [V] and 60 [Hz] is output from the AC terminal of the first bidirectional inverter 12a.

More specifically, the first drive control unit 151a adjusts the duty ratio of the drive voltage applied to the gate terminal of each IGBT of the three-phase AC inverter constituting the first bidirectional inverter 12a. When the voltage applied to the first type load 71 decreases during a power failure, the first drive control unit 151a increases the duty ratio of the drive voltage. Conversely, when the voltage applied to the first type load 71 increases, the first drive control unit 151a decreases the duty ratio of the drive voltage. By such feedback control, the first drive control unit 151a performs control so that the value of the voltage applied to the first type load 71 maintains the target voltage value.

The first determination unit 153a calculates the output capacity of the first bidirectional inverter 12a based on the current value acquired from the first detector 20 and the target voltage value. The first determination unit 153a compares the calculated output capacity with the rated output capacity of the first bidirectional inverter 12a, and determines whether the former exceeds the latter.

In this specification, an example in which the rated output capacity of the first bidirectional inverter 12a is 10 [kVA] and the capacity of the first type load 71 is 15 [kVA] is considered. Hereinafter, in order to simplify the explanation, the power factor of the first bidirectional inverter 12a and the first type load 71 is ignored. Thus, in this specification, it is assumed that the power supply within the range of the rated output capacity from one power storage system 10 does not satisfy the capacity of the first type load 71. Therefore, a plurality of power storage systems 10 need to supply power to the first type load 71 in cooperation.

The first current value calculation unit 154a should output from the second power storage system 10b to the first node N1 when the calculated output capacity of the first bidirectional inverter 12a exceeds the rated output capacity of the first bidirectional inverter 12a. Calculate the current value. In the present embodiment, the current of the rated output capacity of the first bidirectional inverter 12a is output from the first power storage system 10a of the master, and the shortage of current is output from the second power storage system 10b of the slave. In the above example, the first power storage system 10a shares 10 [kVA], and the second power storage system 10b shares 5 [kVA].

Note that the output capacity determination processing by the first determination unit 153a described above may be skipped. That is, the first current value calculation unit 154a calculates the value of the current to be output from the second power storage system 10b to the first node N1 on the condition that a power failure occurs. When the value of this current becomes negative, the capacity of the first type load 71 is satisfied only by the power supply from the first power storage system 10a.

The instruction unit 155a instructs the second control unit 15b to output a current to the first node N1 via the first storage battery management unit 16a and the second storage battery management unit 16b. At that time, the value of the current to be shared by the second power storage system 10b is instructed.

Next, the slave second control unit 15b will be described. The 2nd acquisition part 152b acquires the value of the voltage applied to the 1st type load 71 from the 1st detector 20 or the 2nd detector 30 at the time of a power failure. The value of the current flowing from the second bidirectional inverter 12b to the first node A1 is acquired from the second detector 30. That is, the value of the output current of the second power storage system 10b is acquired.

The second drive control unit 151b drives and controls the second bidirectional inverter 12b so as to output an AC voltage synchronized with the voltage detected from the first detector 20 or the second detector 30 in the event of a power failure. Specifically, the second bidirectional inverter 12b is caused to generate an AC voltage having a phase and frequency synchronized with the phase and frequency of the AC voltage detected from the second detector 30. The phase and frequency can be specified by observing the voltage detected from the first detector 20 or the second detector 30 in time series. For example, by counting the time between zero crossings, the phase and frequency of the AC voltage output from the first bidirectional inverter 12a can be specified.

The instruction receiving unit 155b receives a current output command from the instruction unit 155a. At that time, the current value to be shared by the second power storage system 10b is also received. Its value is given as an effective value. The target value calculation unit 158b calculates a target current value at each time based on the value of the current received by the instruction receiving unit 155b and the phase and frequency of the AC voltage described above. The target value calculation unit 158b may calculate a target current value for each sampling point for one cycle to create a target current value table, or may continue to calculate the target current value for each sampling point in real time. Good. The sampling point is set, for example, every 15 [kHz].

The second drive control unit 151b is configured so that the current value detected from the second detector 30 at each sampling point matches the target current value of the corresponding sampling point calculated by the target value calculation unit 158b. The bidirectional inverter 12b is driven and controlled. When the former is larger than the latter, the second drive control unit 151b decreases the duty ratio of the drive voltage for driving the second bidirectional inverter 12b. On the other hand, when the former is smaller than the latter, the second drive controller 151b increases the duty ratio of the drive voltage. A constant current output can be realized by such feedback control.

FIG. 4 is a flowchart for explaining the operation of the power distribution system 50 according to the first embodiment of the present invention. In the following flowcharts of the present specification, the process indicated by the reference sign of step S100 indicates the process of the first power storage system 10a, and the process indicated by the reference sign of step S200 indicates the process of the second power storage system 10b. .

The process shown in the flowchart of FIG. 4 is a process from when a power failure occurs until a state where stable power is supplied to the first type load 71 by the cooperative operation of the first power storage system 10a and the second power storage system 10b. Is shown.

When a power failure occurs (Y in S100), the master first drive control unit 151a determines the voltage and frequency in the self-sustaining operation mode (S110). Preset values can be used for the voltage and frequency. In this specification, 200 [V] and 60 [Hz] are used.

The first drive control unit 151a drives and controls the first bidirectional inverter 12a so as to supply AC power having the voltage and frequency to the first type load 71 (S120). As a result, power supply to the first type load 71 is started.

The first acquisition unit 152a acquires the value of the current flowing from the first detector 20 to the first type load 71 (S130). The first current value calculation unit 154a calculates the difference between the acquired current value and the current value of the rated output capacity of the first bidirectional inverter 12a, and calculates the insufficient current value (S140). . This insufficient current value is a current value that is insufficient when the maximum current is output within the range of the rated output capacity from the first bidirectional inverter 12a at the target voltage value. When the capacity of the first type load 71 is large, the output voltage of the first bidirectional inverter 12a decreases. On the other hand, the first drive control unit 151a drives and controls the first bidirectional inverter 12a so as to maintain the output voltage, so that the output current of the first bidirectional inverter 12a increases. When the output current exceeds the maximum within the range of the rated output capacity, the current shortage occurs.

The instruction unit 155a instructs the second control unit 15b of the slave to give a current output instruction including the calculated insufficient current value (S150). The slave instruction receiving unit 155b acquires a current output instruction from the master instruction unit 155a (S200). The second acquisition unit 152b acquires the value of the voltage applied to the first type load 71 from the first detector 20 or the second detector 30 (S210).

The second drive controller 151b drives and controls the second bidirectional inverter 12b so as to output the instructed current with a voltage synchronized with the voltage waveform detected by the first detector 20 or the second detector 30 ( S220). As a result, the current from the first power storage system 10 a and the combined current from the second power storage system 10 b are supplied to the first type load 71.

The second acquisition unit 152b acquires the value of the current flowing from the second detector 30 into the first node N1 from the second bidirectional inverter 12b (S230). The second drive control unit 151b determines whether or not the acquired current value matches the target current value (S240). If the current value does not match (N in S240), the second bidirectional inverter 12b Is adjusted (S250), and the process proceeds to step S230. The target current value is calculated by the target value calculation unit 158b based on the current value included in the current output instruction and the phase and frequency of the voltage detected by the first detector 20 or the second detector 30. Calculated.

When it is determined by the second drive control unit 151b that both match (Y in S240), the master first acquisition unit 152a is applied to the first type load 71 from the first detector 20 or the second detector 30. The value of the current voltage is acquired (S170).

The first determination unit 153a determines whether or not the first type load 71 is satisfied from the voltage value detected by the first detector 20 or the second detector 30 (S180). If the detected voltage value matches the above-mentioned target voltage value, the first type load 71 is satisfied. If the two do not match, the first type load 71 is not satisfied. When the current added from the second power storage system 10b is insufficient, the detected voltage value is lower than the target voltage value.

If the request for the first type load 71 is not satisfied (N in S180), the process proceeds to step S130, and the processes from step S130 to step S170 are repeated. When the request for the first type load 71 is satisfied (Y in S180), one unit of the independent operation control at the time of power failure is terminated by cooperation between the first power storage system 10a and the second power storage system 10b at the time of power failure. . Thereafter, each time the capacity of the first type load 71 fluctuates, this independent operation control is repeated.

As described above, according to the first embodiment, the value of the current that the master first power storage system 10a is insufficient at the time of a power failure is calculated, and the current output of that value is instructed to the slave second power storage system 10b. Thereby, a some electrical storage system can be efficiently collaborated at the time of a power failure. Moreover, since it drive | operates so that the rating of the master 1st electrical storage system 10a may not be exceeded, safety | security is high. When such a plurality of power storage systems can be operated in a coordinated manner, a small-sized or medium-sized power storage system can support a small first type load 71 to a large first type load 71. Expansion to an existing power storage system is easy, and the overall scale of the power storage system can be flexibly adjusted.

(Embodiment 2)
FIG. 5 is a diagram showing a configuration of a power distribution system 50 according to Embodiment 2 of the present invention. The power distribution system 50 according to the second embodiment has a configuration in which a third detector 35 is added to the power distribution system 50 according to the first embodiment. Hereinafter, description common to the power distribution system 50 according to Embodiment 1 will be omitted as appropriate, and differences will be described.

The third detector 35 is provided between the AC output terminal of the first bidirectional inverter 12a of the first power storage system 10a and the first node N1. The third detector 35 includes a current sensor and a voltage sensor. The third detector 35 detects the value of the current flowing from the first bidirectional inverter 12a into the first node N1, and notifies the first controller 15a. The voltage value of the first node N1 is detected and notified to the first controller 15a.

The third detector 35 and the first control unit 15a are connected by a LAN cable or an RS-232C cable made of an optical fiber, and optically communicate between them. Note that all of the first detector 20, the second detector 30, and the third detector 35 do not have to include voltage sensors, and any one of them may be provided. For example, when only the 1st detector 20 is provided with a voltage sensor, the 1st detector 20 notifies the value of the detected voltage to both the 1st control part 15a and the 2nd control part 15b.

In the second embodiment, the target value holding unit 158a further holds a current value corresponding to the voltage and frequency of the AC power to be output from the first bidirectional inverter 12a when performing a self-sustained operation during a power failure. The target value holding unit 158a may hold a target current value of each sampling point for one cycle in a table, or may hold a mathematical formula for calculating the target current value.

In the second embodiment, the first drive controller 151a drives the first bidirectional inverter 12a at a constant voltage before instructing the second power storage system 10b to output current, and after instructing the first bidirectional inverter 12a. Is driven at a constant current. In the case of constant voltage driving, the first drive control unit 151a performs the first bidirectional so that the voltage value detected from the first detector 20 or the like at each sampling point matches the target voltage value at the corresponding sampling point. The inverter 12a is driven and controlled. In the case of constant current driving, the first drive control unit 151a uses the first bidirectional inverter so that the current value detected from the third detector 35 at each sampling point matches the target current value at the corresponding sampling point. 12a is driven and controlled.

In the second embodiment, the current value calculation unit 154a apportions the value of the current acquired from the first detector 20 by the number of power storage systems 10 connected to the first node N1, and from each power storage system 10. The value of the current to be output to the first node N1 is calculated. When M (natural number) power storage systems are connected to the first node N1, the current value calculation unit 154a sets the current value to 1 / M. In the present embodiment, the first power storage system 10a and the second power storage system 10b are connected to the first node N1. Therefore, the current value calculation unit 154a halves the current value. In the above example, the first power storage system 10a shares 7.5 [kVA], and the second power storage system 10b shares 7.5 [kVA]. The number of power storage systems 10 connected to the first node N1 may be stored in advance in the first control device 14a, or the value of the current to be output from each power storage system 10 to the first node N1. It may be detected when calculating.

In Embodiment 2, the first determination unit 153a is not an essential element of the first control unit 15a. In the second embodiment, regardless of the value of the current detected from the first detector 20, the current value calculation unit 154a distributes the value by the number of power storage systems connected to the first node N1. As in the first embodiment, the first determination unit 153a calculates the output capacity of the first bidirectional inverter 12a based on the current value acquired from the first detector 20, and calculates the calculated output capacity and The rated output capacity of the first bidirectional inverter 12a may be compared. Only when the former exceeds the latter, the current value calculation unit 154a performs the above-described distribution process.

FIG. 6 is a flowchart for explaining the operation of the power distribution system 50 according to the second embodiment of the present invention. The flowchart in FIG. 6 is different from the flowchart in FIG. 4 in that the processes in steps S140 and S150 are replaced with the processes in steps S141 and S151, respectively, and the processes in steps S161, S162, and S163 are added. is there.

The processing from step S100 to step S130 in FIG. 6 is the same as those in FIG. The first current value calculation unit 154a apportions the current value acquired from the first detector 20 by the number of power storage systems connected to the first node N1 (S141).

The instruction unit 155a instructs the second control unit 15b to give a current output instruction including a current value to be shared by the slave second power storage system 10b (S151). In the present embodiment, since the first power storage system 10a and the second power storage system 10b are connected to the first node N1, the second value is output so that half of the current value detected by the first detector 20 is output. The control unit 15b is instructed. The processing from step S200 to step S240 is the same as those processing in FIG.

When it is determined that the current value acquired from the second detector 30 by the second drive control unit 151b matches the target current value (Y in S240), the first acquisition unit 152a of the master uses the first bidirectional inverter The value of the current flowing from 12a into the first node N1 is acquired from the third detector 35 (S161). The first drive control unit 151a determines whether or not the acquired current value matches the target current value (S162). If the current value does not match (N in S162), the first bidirectional inverter 12a makes the two match. The drive voltage duty ratio is adjusted (S163). The target current value is held in the target value holding unit 158a. In addition, you may calculate in real time based on numerical formula. The process in step S180 is the same as the process in step S180 in FIG.

As described above, according to the second embodiment, the value of the current to be supplied to the first type load 71 is apportioned by the number of power storage systems 10 that can supply power to the first type load 71 in the event of a power failure. And the electric current which each should share to each 1st type load 71 is supplied in parallel from each electrical storage system. Thereby, in addition to the effect which concerns on the above-mentioned Embodiment 1, there exist the following effects. The usage amount of each storage battery 11 of the plurality of power storage systems 10 included in the power distribution system 50 can be leveled. Therefore, the life of the storage battery 11 of each power storage system 10 can be leveled. Further, it is possible to supply power to the first type load 71 for a long time without switching the power storage system 10. Further, cooperative operation of three or more power storage systems 10 is easy.

(Embodiment 3)
Next, a power distribution system 50 according to Embodiment 3 of the present invention will be described. The power distribution system 50 according to the third embodiment has the same configuration as the power distribution system 50 according to the second embodiment in FIG. Hereinafter, description common to the power distribution system 50 according to Embodiment 2 will be omitted as appropriate, and differences will be described.

In the third embodiment, the current value calculation unit 154a determines the current to be output from each power storage system 10 according to the ratio of the remaining capacity in each storage battery 11 of the plurality of power storage systems 10 connected to the first node N1. Calculate the value. In the present embodiment, the first storage battery management unit 16a acquires the remaining capacity of the first storage battery 11a. The 1st storage battery management part 16a notifies the acquired remaining capacity to the 1st control part 15a. The 2nd storage battery management part 16b acquires the remaining capacity of the 2nd storage battery 11b. The 2nd storage battery management part 16b notifies the acquired remaining capacity to the 1st control part 15a via the 1st storage battery management part 16a. When the capacity | capacitance of the 1st storage battery 11a and the 2nd storage battery 11b is equal, the 1st storage battery management part 16a and the 2nd storage battery management part 16b can represent remaining capacity with SOC (State | of-of-charge | Charge).

The current value calculation unit 154a calculates the ratio of the current that should flow from the first power storage system 10a and the current that should flow from the second power storage system 10b based on the SOC ratio between the first storage battery 11a and the second storage battery 11b. For example, when the SOC of the first storage battery 11a is 60% and the SOC of the second storage battery 11b is 30%, the current value calculation unit 154a causes the current to flow from the first power storage system 10a and the current to flow from the second power storage system 10b. The ratio is determined to be 2: 1. In the above example, the first power storage system 10a shares 10 [kVA], and the second power storage system 10b shares 5 [kVA].

In the third embodiment, as in the second embodiment, the first determination unit 153a is not an essential element of the first control unit 15a. In the third embodiment, regardless of the value of the current detected from the first detector 20, the current value calculation unit 154a distributes the value at the remaining capacity ratio. As in the first embodiment, the first determination unit 153a calculates the output capacity of the first bidirectional inverter 12a based on the current value acquired from the first detector 20, and calculates the calculated output capacity and The rated output capacity of the first bidirectional inverter 12a may be compared. Only when the former exceeds the latter, the current value calculation unit 154a performs the above-described distribution process.

FIG. 7 is a flowchart for explaining the operation of the power distribution system 50 according to Embodiment 3 of the present invention. The flowchart of FIG. 7 is obtained by adding step S142 and replacing step S141 with step S143, compared to the flowchart of FIG.

The processing from step S100 to step S130 in FIG. 7 is the same as those in FIG. The storage battery management unit 16 of each power storage system 10 connected to the first node N1 acquires the remaining capacity of the storage battery 11 of each power storage system 10 (S142). The acquired remaining capacity is transmitted to the first control unit 15a. The first current value calculation unit 154a distributes the value of the current detected by the first detector 20 in the ratio of the remaining capacity of each power storage system connected to the first node N1 (S143). Hereinafter, the processes from step S151 to step S180 in FIG. 7 are the same as those in FIG.

As described above, according to the third embodiment, the first type load 71 is supplied according to the ratio of the remaining capacity of the storage battery 11 included in each of the plurality of power storage systems 10 that can supply power to the first type load 71 at the time of a power failure. Distribute the current value to be. Then, a current to be shared is supplied from each power storage system 10 to the first type load 71. Thereby, in addition to the effect which concerns on the above-mentioned Embodiment 1, there exist the following effects. The discharge end times of the storage batteries 11 of the plurality of power storage systems 10 included in the power distribution system 50 can be matched. Further, it is possible to supply power to the first type load 71 for a long time without switching the power storage system 10. Further, cooperative operation of three or more power storage systems 10 is easy.

(Embodiment 4)
FIG. 8 is a diagram showing a configuration of a power distribution system 50 according to Embodiment 4 of the present invention. The power distribution system 50 according to the fourth embodiment is configured such that the first power storage system 10a and the second power storage system 10b of the power distribution system 50 according to the first embodiment are not connected by a communication line. Hereinafter, description common to the power distribution system 50 according to Embodiment 1 will be omitted as appropriate, and differences will be described.

FIG. 9 is a diagram showing the configuration of the first control unit 15a and the second control unit 15b according to Embodiment 4 of the present invention. The first control unit 15a of the first power storage system 10a set as the master includes a first drive control unit 151a, a first acquisition unit 152a, and a target value holding unit 158a. The second power storage system 10b set as a slave includes a second drive control unit 151b, a second acquisition unit 152b, a second determination unit 153b, a second current value calculation unit 154b, a master information holding unit 157b, and a target value calculation unit 158b. Is provided.

In the fourth embodiment, a current output instruction is not notified from the master first control unit 15a to the slave second control unit 15b in the event of a power failure. Therefore, the instruction unit 155a for notifying the instruction and the first current value calculation unit 154a for calculating the value of the current to be output from the slave second power storage system 10b are omitted. Further, in the fourth embodiment, since the master does not determine whether or not the capacity of the first type load 71 is satisfied only by the power from the first power storage system 10a, the first determination unit 153a is also omitted. In the fourth embodiment, this determination is performed by the slave second power storage system 10b. The operations of the first drive control unit 151a, the first acquisition unit 152a, and the target value holding unit 158a are the same as those in the first embodiment.

In the fourth embodiment, a second determination unit 153b, a second current value calculation unit 154b, and a master information holding unit 157b are added to the slave second control unit 15b. The 2nd acquisition part 152b acquires the value of the voltage applied to the 1st type load 71 from the 1st detector 20 or the 2nd detector 30 at the time of a power failure. Further, the value of the current flowing through the first type load 71 is acquired from the first detector 20. The value of the current flowing from the second bidirectional inverter 12b to the first node A1 is acquired from the second detector 30. That is, the value of the output current of the second power storage system 10b is acquired.

The master information holding unit 157b has the rated output capacity of the first power storage system 10a set as the master, the voltage and frequency values used in the self-sustaining operation at the time of a power failure, and the rated output in the case of being driven by the voltage value Holds the maximum output current that satisfies the capacity.

The second determination unit 153b only supplies power from the first power storage system 10a to the first type load 71 based on the voltage or current value acquired from the first detector 20, and the first type load 71 It is determined whether the capacity is satisfied. Specifically, when the voltage acquired from the first detector 20 is lower than “the value of the voltage used in the self-sustaining operation at the time of power failure” held in the master information holding unit 157b, or the first detector When the current acquired from 20 exceeds the “maximum output current value” held in the master information holding unit 157b, it is determined that the capacity of the first type load 71 is not satisfied, otherwise the first type load It is determined that the capacity of 71 is satisfied.

The second current value calculation unit 154b performs the second current value calculation unit 154b from the second power storage system 10b set as a slave when the power supply from the first power storage system 10a alone does not satisfy the capacity of the first type load 71. The value of the current to be output to one node N1 is calculated. Specifically, the second current value calculation unit 154b subtracts the value of the maximum output current of the first power storage system 10a from the value of the current acquired from the first detector 20, and from the second power storage system 10b. Calculate the current value to be output.

The second drive control unit 151b is configured to output a voltage value acquired from the first detector 20 or the second detector 30 and an AC power synchronized with the frequency from the AC side output terminal at the time of a power failure. The direction inverter 12b is driven and controlled.

Further, the second drive control unit 151b drives and controls the second bidirectional inverter 12b so as to output the current having the value calculated by the second current value calculation unit 154b to the first node N1. The second drive control unit 151b is configured so that the current value detected from the second detector 30 at each sampling point matches the target current value of the corresponding sampling point calculated by the target value calculation unit 158b. The bidirectional inverter 12b is driven and controlled.

In Embodiment 4, since the current output instruction is not received from the first control unit 15a, the instruction receiving unit 155b is omitted.

FIGS. 10A to 10B are flowcharts for explaining the operation of the power distribution system 50 according to the fourth embodiment of the present invention. The flowchart in FIG. 10A shows the operation of the first power storage system 10a, and the flowchart in FIG. 10B shows the operation of the second power storage system 10b.

In the flowchart of FIG. 10A, when a power failure occurs (Y in S100), the master first drive control unit 151a determines the voltage and frequency in the self-sustaining operation mode (S110). The first drive control unit 151a drives and controls the first bidirectional inverter 12a so as to supply AC power having the voltage and frequency to the first type load 71 (S120). Hereinafter, the first drive control unit 151a performs constant voltage driving so as to maintain the voltage. In the fourth embodiment, since the current that the slave second power storage system 10b is short of is adjusted, the independent operation start-up process of the master first power storage system 10a is as described above.

10B, the second acquisition unit 152b acquires the value of the voltage applied to the first type load 71 from the first detector 20 or the second detector 30 (S300). The second determination unit 153b determines whether or not additional power supply from the slave second power storage system 10b to the first type load 71 is necessary (S310). If not necessary (N in S310), the independent operation start-up process of the slave second power storage system 10b is completed.

When additional power supply is necessary (Y in S310), the second acquisition unit 152b acquires the value of the current flowing through the first type load 71 from the first detector 20 (S320). The second current value calculation unit 154b calculates the difference between the acquired current value and the allowable maximum output current value of the first bidirectional inverter 12a, and calculates the insufficient current value (S330). ).

The second drive control unit 151b drives and controls the second bidirectional inverter 12b so as to output a calculated current with a voltage synchronized with the voltage waveform detected by the first detector 20 or the second detector 30. (S340). As a result, the current from the first power storage system 10 a and the combined current from the second power storage system 10 b are supplied to the first type load 71.

The second acquisition unit 152b acquires the value of the current flowing from the second bidirectional inverter 12b into the first node N1 from the second detector 30 (S350). The second drive control unit 151b determines whether or not the acquired current value matches the target current value (S360). If they do not match (N in S360), the second bidirectional inverter 12b Is adjusted (S370), and the process proceeds to step S350. If they match (Y in S360), the process proceeds to step S300.

In the fourth embodiment, the master information holding unit 157b holds various pieces of information related to the first power storage system 10a set as the master, but at least the voltage value used in the independent operation at the time of a power failure. It is only necessary to hold it. Thereby, the 2nd determination part 153b compares the value of the voltage acquired from the 1st detector 20, and the value of the voltage used by the independent operation at the time of the power failure currently hold | maintained, and the 1st electrical storage system 10a It is possible to determine whether or not the capacity of the first type load 71 is satisfied only by supplying power from. In this case, since the master information holding unit 157b does not hold the rated output capacity of the first power storage system 10a, the second current value calculation unit 154b cannot calculate an insufficient current value. Therefore, when the second determination unit 153b determines that the capacity of the first type load 71 is not satisfied only by the power supply from the first power storage system 10a, the second determination unit 153b supplies the first type load 71 from the second power storage system 10b. A predetermined current value is set in advance.

As described above, according to the fourth embodiment, the value of the current that the slave second power storage system 10b lacks in the event of a power failure is calculated and the current is output autonomously. Thereby, in addition to the effect which concerns on the above-mentioned Embodiment 1, there exist the following effects. Both can operate together without communication between the first power storage system 10a and the second power storage system 10b. Therefore, a communication line between the two is not necessary, and wiring can be simplified. Further, when the second power storage system 10b is added later to the power distribution system 50, the first control unit 15a of the first power storage system 10a can operate in the same manner as before the extension. Therefore, the update of the first control unit 15a at the time of expansion can be omitted. The first power storage system 10a may perform a self-sustained operation at the time of a power failure after the addition of the second power storage system 10b and without being aware of the second power storage system 10b as in the case before the extension.

The present invention has been described based on the embodiments. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are within the scope of the present invention. is there.

(Modification 1)
Modification 1 is a modification of the power distribution system 50 according to the first embodiment. The power distribution system 50 according to Embodiment 1 can also employ the configuration shown in FIG. That is, the third detector 35 is provided between the first power storage system 10a and the first node N1. According to the first modification, the first power storage system 10a can also be driven at a constant current after the cooperative operation. Therefore, it becomes easy to change the master of the modified example 2 described later.

(Modification 2)
The modification 2 is a modification applicable to the power distribution system 50 according to the modification 1, the power distribution system 50 according to the second embodiment, or the power distribution system 50 according to the third embodiment. In the second modification, a master can be changed among a plurality of power storage systems 10 included in the power distribution system 50.

FIG. 11 is a diagram illustrating a configuration of the first control unit 15a and the second control unit 15b according to the second modification. The master first control unit 15a according to Modification 2 has a configuration in which a master setting unit 156a is added to the configuration of the first control unit 15a illustrated in FIG. The slave second control unit 15b according to Modification 2 is the same as the second control unit 15b illustrated in FIG.

The master setting unit 156a refers to the deterioration degree of each storage battery 11 of the plurality of storage systems 10 connected to the first node N1, and sets the storage system 10 including the storage battery 11 that is least deteriorated as a master. In the modification 2, the 1st storage battery management part 16a acquires the deterioration degree of the 1st storage battery 11a. The 1st storage battery management part 16a notifies the acquired deterioration degree to the 1st control part 15a. The 2nd storage battery management part 16b acquires the deterioration degree of the 2nd storage battery 11b. The 2nd storage battery management part 16b notifies the acquired deterioration degree to the 1st control part 15a via the 1st storage battery management part 16a. When the capacity | capacitance of the 1st storage battery 11a and the 2nd storage battery 11b is equal, the 1st storage battery management part 16a and the 2nd storage battery management part 16b can represent a deterioration degree by SOH (State | of-of-health). The master setting unit 156a sets the larger SOH as the master.

FIG. 12 is a flowchart for explaining the master setting process according to the second modification. When the master setting timing arrives (Y in S190), the storage battery management unit 16 of each power storage system 10 acquires the deterioration degree of each storage battery 11 (S191). The master setting timing can be set, for example, every week, every month, every three months, or the like. The master setting unit 156a sets the power storage system 10 including the storage battery 11 that is least deteriorated as a master (S192).

According to the second modification, the deterioration degree of the storage batteries 11 of the plurality of power storage systems 10 can be leveled by adding a process for changing the master. This is particularly effective when the usage amount of the storage battery 11 differs greatly between the master and the slave, such as when the slave supplies a current value that is insufficient for the rated output capacity of the master to the load. When the second modification is employed, the circuit configuration shown in FIG. 5 is desirable so that constant current driving can be performed regardless of which of the first power storage system 10a and the second power storage system 10b is a slave. In addition, although the first control unit 15a and the second control unit 15b shown in FIG. 11 include different components, only the components necessary for the description are described in order to facilitate the explanation of the operation of the master and the slave. This is because it is displayed. When the modification 2 is employed, the first control unit 15a and the second control unit 15b actually include all the components of the master and the slave so as to be switched to either the master or the slave.

The invention according to the present embodiment may be specified by the items described below.

[Item 1]
A master power storage system that supplies an alternating current of a predetermined voltage and frequency to a load;
Based on an instruction from the master power storage system, at least one slave power storage system for supplying an alternating current to the load;
A current detector for detecting a current supplied from the master power storage system and the slave power storage system to the load;
A voltage detector for detecting an output voltage and an output frequency of the master power storage system;
With
The master power storage system and the slave power storage system include a storage battery, a power converter disposed between the storage battery and the load, and a control unit that controls each power storage system, and are parallel to the load. Connected,
The control unit of the master power storage system instructs a current value to be supplied to the load by the slave power storage system to the control unit of the slave power storage system based on the current value detected by the current detector,
The control unit of the slave power storage system supplies the load with a current value instructed from the master power storage system at the output voltage and the output frequency detected by the voltage detector. .

[Item 2]
The master power storage system and the slave power storage system are connected to a commercial power source,
The power according to item 1, wherein the master power storage system determines whether the commercial power source is in an energized state or a power failure state, and determines the predetermined voltage and frequency when it is determined that the commercial power source is in a power failure state. Supply system.

[Item 3]
The control unit of the master power storage system acquires the degree of deterioration of the storage battery of each of the master power storage system and the slave power storage system connected to the load, and determines the power storage system including the storage battery that is least deteriorated as the master power storage. The power supply system according to item 1 or 2, wherein the power supply system is set as a system, and a power storage system including another storage battery is set as the slave power storage system.

[Item 4]
3. The power supply system according to item 2, wherein the load is a preset load that can receive power supply from the storage battery preferentially at the time of a power failure of the commercial power source.

[Item 5]
A master power storage system of a power supply system comprising: a master power storage system that supplies an alternating current to a load; and at least one slave power storage system that supplies an alternating current to the load based on an instruction of the master power storage system,
A master storage battery,
A master power converter disposed between the master storage battery and the load;
A master control unit that controls the operation of the master power storage system,
The master control unit supplies an alternating current having a predetermined voltage and frequency to the load, and a current value detected by a current detector that detects a current supplied from the master power storage system and the slave power storage system to the load. Based on the above, the slave power storage system instructs the slave power storage system to supply a current value to be supplied to the load.

[Item 6]
The master control unit calculates a current value to be supplied to the load by the slave power storage system based on a current value detected by the current detector and a current value of a rated output capacity of the master power converter. Item 6. The master power storage system according to Item 5.

[Item 7]
When the current value detected by the current detector exceeds the current value of the rated output capacity of the master power converter, the master control unit supplies the current of the rated output capacity from the master power converter to the load. Item 6 is characterized in that the current value instructed to the slave power storage system is a difference between the current value detected by the current detector and the current value of the rated output capacity of the master power converter. The master power storage system described in 1.

[Item 8]
The master control unit divides the current value detected by the current detector by the number of the master power storage system and the slave power storage system connected to the load, and the master power storage system and the slave power storage system respectively. 6. The master power storage system according to item 5, wherein a current value to be supplied to the load is calculated from

[Item 9]
The master control unit acquires remaining capacity data of the master storage battery, acquires remaining capacity data of the storage battery of the slave storage system connected to the load, and stores the remaining capacity data of the master storage battery and the storage battery of the slave storage system. 6. The master power storage system according to item 5, wherein a current value to be supplied to the load is calculated from each of the master power storage system and the slave power storage system according to a capacity ratio.

[Item 10]
The master control unit
A drive control unit that drives and controls the master power converter so as to output AC power of the predetermined voltage and frequency to the load;
An acquisition unit for acquiring a current value from the current detector;
A current calculation unit for calculating a current value for instructing the slave power storage system;
The master power storage system according to any one of items 5 to 9, further comprising: an instruction unit that instructs the slave power storage system to output the calculated current value to the load.

[Item 11]
A power storage system slave power storage system comprising: a master power storage system that supplies an alternating current to a load; and at least one slave power storage system that supplies an alternating current to the load based on an instruction of the master power storage system,
A slave battery,
A slave power converter disposed between the slave storage battery and the load;
A slave control unit that controls the operation of the slave power storage system,
The slave control unit causes the load to supply a current value instructed from the master power storage system at an output voltage and output frequency detected by a voltage detector that detects an output voltage and an output frequency of the master power storage system. A slave power storage system.

[Item 12]
The slave power storage system according to item 11, wherein the slave control unit acquires the remaining capacity data of the slave storage battery and notifies the master power storage system of the remaining capacity data.

50 power distribution system, 10a first power storage system, 10b second power storage system, 20 first detector, 30 second detector, 40 distribution board, 60 commercial power supply, 70 load, 71 first type load, 72 second type Load, SW1 1st switch, SW2 2nd switch, 11a 1st storage battery, 12a 1st bidirectional inverter, 13a 1st solar battery, SW3a 13th switch, 14a 1st control device, 15a 1st control unit, 16a 1st Storage battery management unit, 11b 2nd storage battery, 12b 2nd bidirectional inverter, 13b 2nd solar battery, SW3b 23rd switch, 14b 2nd control device, 15b 2nd control unit, 16b 2nd storage battery management unit, 151a 1st drive Control unit, 152a first acquisition unit, 153a first determination unit, 154a first current value calculation unit, 155a instruction unit, 156a master setting unit, 158a target value holding unit, 151b second drive control unit, 152b second acquisition unit, 155b instruction reception unit, 35 third Detector, 153b second determination unit, 154b second current value calculation unit, 157b master information holding unit, 158b target value calculation unit.

Claims

A master power storage system that supplies an alternating current of a predetermined voltage and frequency to a load;
Based on an instruction from the master power storage system, at least one slave power storage system for supplying an alternating current to the load;
A current detector for detecting a current supplied from the master power storage system and the slave power storage system to the load;
A voltage detector for detecting an output voltage and an output frequency of the master power storage system;
With
The master power storage system and the slave power storage system include a storage battery, a power converter disposed between the storage battery and the load, and a control unit that controls each power storage system, and are parallel to the load. Connected,
The control unit of the master power storage system instructs a current value to be supplied to the load by the slave power storage system to the control unit of the slave power storage system based on the current value detected by the current detector,
The control unit of the slave power storage system supplies the load with a current value instructed from the master power storage system at the output voltage and the output frequency detected by the voltage detector. .
The master power storage system and the slave power storage system are connected to a commercial power source,
The master power storage system determines whether the commercial power source is in an energized state or a power outage state, and determines the predetermined voltage and frequency when determining that the commercial power source is in a power outage state. Power supply system.
The control unit of the master power storage system acquires the degree of deterioration of the storage battery of each of the master power storage system and the slave power storage system connected to the load, and determines the power storage system including the storage battery that is least deteriorated as the master power storage. The power supply system according to claim 1, wherein the power supply system is set as a system, and a power storage system including another storage battery is set as the slave power storage system.
The power supply system according to claim 2, wherein the load is a preset load that can receive power supply from the storage battery preferentially at the time of a power failure of the commercial power source.
A master power storage system of a power supply system comprising: a master power storage system that supplies an alternating current to a load; and at least one slave power storage system that supplies an alternating current to the load based on an instruction of the master power storage system,
A master storage battery,
A master power converter disposed between the master storage battery and the load;
A master control unit that controls the operation of the master power storage system,
The master control unit supplies an alternating current having a predetermined voltage and frequency to the load, and a current value detected by a current detector that detects a current supplied from the master power storage system and the slave power storage system to the load. Based on the above, the slave power storage system instructs the slave power storage system to supply a current value to be supplied to the load.
The master control unit calculates a current value to be supplied to the load by the slave power storage system based on a current value detected by the current detector and a current value of a rated output capacity of the master power converter. The master power storage system according to claim 5.
When the current value detected by the current detector exceeds the current value of the rated output capacity of the master power converter, the master control unit supplies the current of the rated output capacity from the master power converter to the load. The current value instructed to the slave power storage system is a difference between the current value detected by the current detector and the current value of the rated output capacity of the master power converter. 6. The master power storage system according to 6.
The master control unit divides the current value detected by the current detector by the number of the master power storage system and the slave power storage system connected to the load, and the master power storage system and the slave power storage system respectively. The master power storage system according to claim 5, wherein a current value to be supplied to the load is calculated from
The master control unit acquires remaining capacity data of the master storage battery, acquires remaining capacity data of the storage battery of the slave storage system connected to the load, and stores the remaining capacity data of the master storage battery and the storage battery of the slave storage system. 6. The master power storage system according to claim 5, wherein a current value to be supplied to the load is calculated from each of the master power storage system and the slave power storage system according to a capacity ratio.
The master control unit
A drive control unit that drives and controls the master power converter so as to output AC power of the predetermined voltage and frequency to the load;
An acquisition unit for acquiring a current value from the current detector;
A current calculation unit for calculating a current value for instructing the slave power storage system;
The master power storage system according to claim 5, further comprising: an instruction unit that instructs the slave power storage system to output the calculated current value to the load.
A power storage system slave power storage system comprising: a master power storage system that supplies an alternating current to a load; and at least one slave power storage system that supplies an alternating current to the load based on an instruction of the master power storage system,
A slave battery,
A slave power converter disposed between the slave storage battery and the load;
A slave control unit that controls the operation of the slave power storage system,
The slave control unit causes the load to supply a current value instructed from the master power storage system at an output voltage and output frequency detected by a voltage detector that detects an output voltage and an output frequency of the master power storage system. A slave power storage system.
The slave power storage system according to claim 11, wherein the slave control unit acquires the remaining capacity data of the slave storage battery and notifies the master power storage system of the remaining capacity data.