JP6190224B2 - Power storage system - Google Patents

Description

The present invention performs peak cut and peak shift to reduce the contract electric power charge and the electric power charge to be used. When a power outage occurs during a disaster or the like, power is supplied from the storage battery to a specific load. when provided together with photovoltaic relates to a power storage system for storing electric power generated by the solar power to the battery.

  As an electric power storage system using this type of storage battery, for example, in Patent Document 1, power is supplied from the system to a general load and a specific load at the time of grid connection. The idea of reducing the supply amount of electric power from the storage battery and reducing the battery capacity to reduce the size and the price of the system is shown. However, this is based on the premise that it is used in a power storage device including a storage battery and an inverter unit and a system composed only of a load, and does not consider any connection with photovoltaic power generation. For this reason, it cannot cope with expandability such as when there is no solar power generation and when it does not sell power.

  On the other hand, in Patent Document 2, when the power of solar power generation is larger than the load power, the surplus is sold to the power supply system, while when the load power is larger than the power of solar power generation, Proposed a grid-connected power supply system that sells power from solar power generation and discharges the peak of the used power by discharging from the storage battery so that the used power from the system does not exceed a predetermined threshold Has been.

  However, this grid-connected power supply system directly takes in the direct current generated by the solar cell into the system, and it has not been considered to use a commercially available inexpensive power conditioner. Moreover, since not only the electric power generated by the solar battery but also the electric power discharged by the storage battery flows into the power supply system, there is a problem that the power supply system is adversely affected. Furthermore, there is only one type of load, and no consideration is given to switching from a general load, which is important during a disaster, to a specific load.

JP 2006-320099 A JP 2002-369406 A

  In addition to peak cuts to reduce the peak of power consumption and peak shifts that use inexpensive nighttime electricity during the day, stores, buildings, offices, factories, schools, and public halls are used for power outage measures in the event of a disaster. In recent years, the introduction of power storage systems has begun in public facilities such as these.

  On the other hand, solar power generation has already become widespread in such public facilities due to the government-led feed-in tariff system for renewable energy and the establishment of disaster prevention bases. For this reason, power conditioners used in solar power generation have become inexpensive, and when power storage systems are introduced, solar power generation facilities that combine solar cells and power conditioners have been introduced first. There are many. In addition, when installing a solar power generation facility and a power storage system, if it is a private facility, the surplus power of solar power generation is sold. There are many.

  In this way, the power storage system is not only installed alone, but also when it is installed with solar power generation, or when it is installed with solar power generation, when it is sold or not sold There is. In some cases, a power storage system is introduced first, and a photovoltaic power generation facility is introduced later for interconnection. For each of these various installation conditions, if the power storage system was designed exclusively, the price of the system would be high, especially after the system was installed, such as when solar power generation equipment was introduced later. If is changed, a major remodeling will occur.

  It is not generally accepted by electric power companies to store inexpensive nighttime electricity in the power storage system and discharge it during the daytime when electricity costs are high, and the discharge power from the power storage system is reversed to the power supply system. It is necessary to devise ways to prevent the current from flowing. In addition, when selling power from solar power generation using a fixed-price purchase system, etc., the price for solar power generation is fixed, so the power from solar power generation and the discharge power from the power storage system It is necessary not to mix.

In view of the above problems, without large-scale remodeling, it is possible to connect a solar power generation facility inexpensive commercial products and existing, to provide a power storage system that can reduce the cost the 1 purpose.

The second object of the present invention is to provide a power storage system that can be selected without the presence of power sale from photovoltaic power generation facilities to the power supply system by adding the external controller.

The third object of the present invention, without adversely affecting the power supply system, a power supply system and the photovoltaic power generation facilities and easily connected, to provide a power storage system capable of performing a power sale It is in.

  The present invention controls a bidirectional inverter connected between the power supply system and a storage battery at the time of grid connection to the power supply system, and performs peak shift and peak cut of power supplied from the power supply system. In a power storage system that converts direct current power from the storage battery into alternating current power by the bidirectional inverter and supplies the alternating current power to a load at the time of self-sustained operation disconnected from the power supply system, First switching means that is controlled to be opened and closed so that AC power can be supplied to the load, and a wiring path to which the load is connected on the AC side of the bidirectional inverter is changed from a single-phase two-wire system to a single-phase three-wire system. And a converter for converting into an expression.

According to the first aspect of the present invention, when the first switching means and the converter are added to the existing power storage system, AC power combining the solar cell and the power conditioner is output without major modification. The solar power generation facility can be easily connected to the power storage system. In addition, by adding a converter to the existing power storage system, the discharge power from the storage battery is supplied to various loads that can be connected to a single-phase three-wire wiring path with a configuration in which a photovoltaic power generation facility is connected. It becomes possible. In this way, it is possible to connect an inexpensive commercial product or existing photovoltaic power generation equipment without major modification only by adding the first switching means and the converter to the existing power storage system. The cost as a power storage system can be reduced, and power can be supplied to various loads from a solar power generation facility or a storage battery via a single-phase three-wire wiring path.

According to the second aspect of the present invention, solar power generation can be performed without adding an external controller by controlling the opening and closing of the second switching means on the power storage system side with the configuration in which the second switching means is added. Power can be sold from the facility to the power supply system.

According to the invention of claim 3 , by using the first switching means added and controlling the opening and closing of the first switching means, the reverse power flow from the storage battery to the power supply system can be completely prevented. . Therefore, it is possible to easily connect the power supply system and the solar power generation facility and perform power sales without adversely affecting the power supply system.

  According to the invention of claim 4, the power storage system is gradually expanded to the first system configuration, the second system configuration, or the third system configuration according to the entire system configuration, and the expanded first switching is performed. By switching control of the means and the second switching means on the power storage system side, it becomes possible to eliminate large-scale remodeling of the power storage system due to the presence or absence of solar power generation facilities or the sale or non-sale of power from solar power generation facilities It is possible to reduce the cost for system construction.

1 is a block diagram of an overall system configuration showing an embodiment of the present invention. It is explanatory drawing regarding three system configurations of an electric power storage system same as the above. It is a block block diagram which shows the structure and operation | movement state of an electric power storage system at the time of the grid connection of a 1st system structure same as the above. It is a block block diagram which shows the structure and operating state of an electric power storage system at the time of the independent operation of a 1st system structure same as the above. It is explanatory drawing which shows the operation state of each switching means in a 1st system structure same as the above. It is a block block diagram which shows the structure and operating state of an electric power storage system at the time of the grid connection of a 2nd system structure same as the above. It is a block block diagram which shows the structure and operating state of an electric power storage system at the time of the independent operation of a 2nd system structure same as the above. It is explanatory drawing which shows the operation state of each switching means in a 2nd system structure same as the above. It is a block block diagram which shows the structure and operation | movement state of an electric power storage system at the time of the grid connection of a 3rd system structure same as the above. It is a block block diagram which shows the structure and operating state of an electric power storage system at the time of the independent operation of a 3rd system structure same as the above. It is explanatory drawing which shows the operation state of each switching means in a 3rd system structure same as the above.

  Hereinafter, a preferred embodiment of the power storage system and its control method according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 schematically shows the entire system configuration including the power storage system 1. In the figure, reference numeral 2 denotes a power supply system provided by an electric power company, and 3 denotes an AC 200 V single-phase three-wire power supply path that is connected to the power supply system 2 and drawn into a public or private power receiving facility 4. An AC 100V general load 5A is detachably connected between the voltage line of the power supply path 3 and the neutral line, and an AC 200V general load 5B is attached and detached between the voltage lines of the power supply path 3. The system power from the power supply system 2 is connected to the general loads 5 </ b> A and 5 </ b> B via the power supply path 3. In addition, a current transformer 6 serving as a current detector is disposed in the power supply path 3 in order to detect the amount of current supplied from the power supply system 2 to the power receiving facility 4.

  A system main body 7 of the power storage system 1 is connected to the power supply path 3 in parallel with the general loads 5A and 5B. The system body 7 operated in connection with the power supply system 2 includes an inverter unit 8, a storage battery 9, a second switching unit 12, a third switching unit 13, and first wiring paths 31 to 31 that connect these parts. It is comprised by the 4th wiring path 34, and the 4th switching means 14 and the transformer 16 are additionally equipped as needed. Further, the system main body 7 is provided with a solar power generation connection terminal 17 that enables input of generated power from the solar power generation facility 21. The storage battery 9 is comprised by secondary batteries, such as a lithium ion battery, for example.

  In addition to the first switching means 11, the inverter unit 8 controls the bidirectional inverter 18 including one or more semiconductor switching elements (not shown) and capable of bidirectional power conversion, and the bidirectional inverter 18. And a controller 19. The bidirectional inverter 18 is connected to a first wiring path 31 between the power supply path 3 and the storage battery 9, receives a charge control signal from the controller 19, and converts AC power from the power supply path 3 into DC power. In addition, in response to a discharge control signal from the controller 19, the DC power from the storage battery 9 is converted into AC power. The controller 19 also provides information on the current from the power supply system 2 detected by the current transformer 6 to the power receiving facility 4, information on the current and voltage on the AC side of the bidirectional inverter 18 measured by the inverter unit 8, and the like. It has a function of taking in and generating a charge control signal and a discharge control signal for the bidirectional inverter 18 and performing control such as peak shift and peak cut at the time of grid connection with the power supply system 2. Further, the controller 19 controls the first switching means 11 to the fifth switching means 15.

  The first switching unit 11 is inserted and connected to the first wiring path 31 between the power supply path 3 and the bidirectional inverter 18.

  In addition to the first wiring path 31 described above, the system body 7 includes a second wiring path 32 into which the second switching means 12 is inserted and connected, and a third wiring into which the transformer 16 and the third switching means 13 are inserted and connected. A path 33 and a fourth wiring path 34 into which the fourth switching means 14 is inserted and connected are provided. The second wiring path 32 has one end connected to the first wiring path 31 between the power feeding path 3 and the first switching means 11 and the other end connected to the third wiring path 33. The third wiring path 33 has one end connected to the first wiring path 31 between the first switching means 11 and the bidirectional inverter 18, and between this one end and the connection point to which the other end of the second wiring path 32 is connected. In addition, the transformer 16 and the third switching means 13 are inserted and connected in order. Furthermore, the other end side of the third wiring path 33 is extended to the outside of the system main body 7, and is configured such that a specific load 41 </ b> A of AC 100 V or a specific load 41 </ b> B of AC 200 V can be connected there. The fourth wiring path 34 has one end connected to the photovoltaic power generation connection terminal 17 and the other end connected to the second wiring path 32 between the second switching means 12 and the third wiring path 33.

  The photovoltaic power generation facility 21 is configured by incorporating a power conditioning system (PCS) 23 including an inverter into a solar cell 22 that receives sunlight to generate power, and the DC power generated by the solar cell 22. Is converted into AC power by the PCS 23 and output. The solar power generation equipment 21 and the solar power generation connection terminal 17 of the system main body 7 are connected by the fifth wiring path 35, and AC power from the PCS 23 is supplied to the system main body 7 through the solar power generation connection terminal 17. It becomes the composition which is done. In addition, a sixth wiring path 36 is connected between the fifth wiring path 35 and the power supply system 51 in order to sell the AC power from the PCS 23 to the power supply system 51 contracted separately from the power supply system 2 by a reverse flow. Is done. The fifth switching means 15 is inserted and connected to the sixth wiring path 36, and includes the system main body 7 described above and the fifth switching means 15 provided outside the system main body 7. System 1 is configured.

  Each of the first switching means 11 to the fifth switching means 15 as a switch is connected to a control controller 19 as a control unit by a signal line (not shown), and in accordance with a control signal from the control controller 19, respectively. Open and close independently. Further, in this embodiment, when the solar power generation facility 21 is not introduced and only the system main body 7 operates, the transformer 16 and the fourth switching unit 14 are connected to the power storage system 1 in addition to the fifth switching unit 15. From the photovoltaic power generation equipment 21, the first and second switching means 11 to 13 are switched and controlled by the controller 19 in accordance with the presence or absence of power supplied from the power supply system 2. When the generated power is not used for selling power to the power system 51 of another system but is used only by the system main body 7, the transformer 16 and the fourth switching means 14 are mounted on the power storage system 1, while 5 switching means 15 is removed from the power storage system 1, the photovoltaic power generation equipment 21 is connected to the photovoltaic power generation connection terminal 17 via the fifth wiring path 35, and the power supply from the power supply system 2 is present. In accordance with the second system configuration in which the control controller 19 switches and controls the opening and closing of the first switching means 11 to the fourth switching means 14, respectively, the generated power from the photovoltaic power generation equipment 21 is not only the system body 7, When the power is also used for selling power to the power system 51, in addition to the transformer 16 and the fourth switching means 14, the fifth switching means 15 is also attached to the power storage system 1, and sunlight is passed through the fifth wiring path 35. The power generation facility 21 is connected to the solar power generation connection terminal 17 and the fifth wiring path 35 and the power supply system 51 are connected via the sixth wiring path 36 to which the fifth switching means 15 is inserted and connected. In accordance with the presence / absence of power supplied from the control unit 19, the control system 19 switches and controls the opening and closing of the first switching unit 11 to the fifth switching unit 15.

  Next, each operation of the first to third system configurations will be described. FIG. 2 shows a list of diagram numbers corresponding to the operation states of each system configuration. Here, first, the operation of the basic first system configuration without the solar power generation facility 21 will be described, and then the extended second system that has the solar power generation facility 21 and does not sell power to the power system 51. The configuration and the further expanded third system configuration having the photovoltaic power generation facility 21 and selling power to the power supply system 51 will be described in order.

  Regarding the first system configuration, FIG. 3 shows the configuration of the power storage system 1 at the time of grid connection and the operating state of each part, and FIG. 4 shows the configuration of the power storage system 1 at the time of self-sustained operation and the operating state of each part. 5 shows a list of operation states of the first switching means 11 to the fifth switching means 15.

  As described above, in the first system configuration in which the solar power generation facility 21 does not exist, the transformer 16 and the fourth switching means 14 are not provided inside the system main body 7, and the solar power generation facility 21 is also provided outside the system main body 7. Needless to say, the fifth switching means 15 is not equipped either. In the first system configuration, an example is shown in which only the specific load 41A of AC 100V is connected and the specific load 41B of AC 200V is not connected. For this reason, as shown in FIG. 3 and FIG. 4, the third wiring path 33 is not connected to the transformer 16 in the middle, but only the third switching means 13 is inserted and connected, so that the AC 100V single-phase two-wire Only the specific load 41 </ b> A of AC 100 V is connected to the third wiring path 33, and power can be supplied from the inverter unit 8 to the specific load 41 </ b> A via the second wiring path 32. This is because, in the inverter unit 8, the line between the first switching means 11 of the first wiring path 31 and the bidirectional inverter 18 is a single-phase two-wire system of AC 100V, and a specific load 41B of AC 200V cannot be connected. Due to that.

  Here, when the controller 19 determines that power is supplied from the power supply system 2 to the power receiving equipment 4 based on the detection signal from the current transformer 6, the power storage system 1 is connected to the power supply system 2. Therefore, the first switching means 11 and the second switching means 12 are set to “ON”, that is, closed, and the third switching means 13 is set to “OFF”, that is, switched to the open state. When it is determined that power is not supplied from the grid 2 to the power receiving facility 4, the first switching means 11 and the second switching means 12 are set to “ “Turn off”, that is, open state, and switch the third switching means 13 to “On”, that is, close state. Here, an example in which it is determined that the power is supplied from the power supply system 2 based on the detection signal from the current transformer 6 is shown. However, the voltage of the power feeding path 31 is measured in the inverter unit 8, and the voltage detection signal is used. You may judge.

  As shown in FIG. 3, when the power storage system 1 in the first system configuration is connected to the grid, the power storage system 1 is connected to the power supply system 2 by the first switching unit 11 and the second switching unit 12 that are in the closed state. Then, the system power from the power supply system 2 is supplied to the general loads 5A and 5B connected to the power supply path 3 and supplied to the specific load 41A connected to the third wiring path 33 via the second switching means 12. Is done. Further, in the inverter unit 8, for example, the storage battery 9 is charged in a time zone such as nighttime when the electricity bill is low, and the storage battery 9 is discharged in a time zone such as daytime when the electricity bill is high, thereby leveling the power consumption of the power receiving equipment 4. In order to achieve this, a peak shift or current transformer for sending a charge control signal or a discharge control signal to the bidirectional inverter 18 in a predetermined time zone by using a timing means (not shown) built in the controller 19 6 and the voltage information on the AC side of the bidirectional inverter 18, the system power amount from the power supply system 2 is calculated, and the controller 19 does not exceed the predetermined value so that the calculated system power amount does not exceed a predetermined value. A discharge control signal is sent to the bidirectional inverter 18 to discharge the storage battery 9 and a peak cut is performed to cut the amount of power used by the power receiving equipment 4. As a result, while the charging control signal is sent from the controller 19 to the bidirectional inverter 18, the system power from the power supply system 2 is applied to the bidirectional inverter 18 via the first switching means 11, and is converted here. While the supplied DC power is supplied to the storage battery 9 to charge the storage battery 9, the DC power from the storage battery 9 is supplied to the bidirectional inverter while the discharge control signal is sent from the controller 19 to the bidirectional inverter 18. 18 is converted into AC power, and the converted AC power is supplied to the general loads 5A and 5B via the first switching means 11 so as to supplement the system power from the power system 2 to the power receiving equipment 4, and further 2 is also supplied to the specific load 41 </ b> A via the switching unit 12. When the controller 19 detects a reverse power flow using the detection signal from the current transformer 6, the output of the bidirectional inverter 18 is connected to the power supply system 2 by turning the first switching means 11 off. Reverse tide can be completely prevented. That is, the power stored in the storage battery 9 can be prevented from flowing into the power supply system 2. Here, an example in which the grid power amount from the power supply system 2 is calculated using the detection signal from the current transformer 6 is shown, but the power amount is output using the output pulse of the maximum demand watt-hour meter installed by the power company. May be calculated.

  Further, as shown in FIG. 4, during the self-sustaining operation of the power storage system 1 in the first system configuration, the power storage system 1 is disconnected from the power supply system 2 by the first switching unit 11 and the second switching unit 12 that are open. It is. In this case, although the power supply from the power supply system 2 to the general loads 5A and 5B is cut off, the inverter unit 8 is supplied from the controller 19 to supply power to the specific load 41A connected to the third wiring path 33. A discharge control signal is sent to the bidirectional inverter 18. Thereby, the DC power from the storage battery 9 is converted into AC power by the bidirectional inverter 18, and the converted AC power is supplied to the specific load 41 </ b> A via the third switching means 13 in the closed state.

  Thus, in the first system configuration, not only the general loads 5A and 5B connected to the power supply path 3 but also the other end of the third wiring path 33 at the normal time when the power storage system 1 is connected to the grid power supply 2 and connected to the grid. Power is supplied also to the specific load 41A connected to the side, and the bidirectional inverter 18 is operated as necessary to perform peak shift and peak cut of the system power supplied from the system power source 2, and the system power source 2 In the event of a disaster (when a power failure occurs) in which the power storage system 1 is disconnected and the power storage system 1 operates independently, power can be supplied only from the storage battery 9 to the important specific load 41A.

  Next, with respect to the second system configuration, FIG. 6 shows the configuration of the power storage system 1 and the operating state of each part during grid connection, and FIG. 7 shows the configuration of the power storage system 1 and the operating state of each part during autonomous operation. FIG. 8 shows a list of operation states of the first switching means 11 to the fifth switching means 15.

  In the second system configuration in which the solar power generation facility 21 is provided but no power is sold from the solar power generation facility 21 to the power supply system 51, the transformer 16 and the fourth switching means 14 are provided inside the system body 7. Then, outside the system main body 7, the solar power generation facility 21 is connected to the solar power generation connection terminal 17 of the system main body 7 via the fifth wiring path 35, but the fifth switching means 15 is not provided. In the photovoltaic power generation facility 21, the DC power generated by the solar cell 22 is converted into AC power by the PCS 23, and the converted AC power passes through the single-phase three-wire fifth wiring path 35 of AC 200V. The solar power generation connection terminal 17 of the system body 7 is supplied. The transformer 16 converts the AC 200V single-phase two-wire system into an AC 200V single-phase three-wire system. When the transformer 16 is inserted and connected in the middle of the third wiring path 33, the other end side of the third wiring path 33 becomes closer to the transformer 16 than the transformer 16. By connecting a specific load 41A of AC 100V or a specific load 41B of AC 200V to the side, power can be supplied to these specific loads 41A and 41B from the inverter unit 8 via the third wiring path 33. Become. That is, the transformer 16 here is a single-phase two-wire wiring path connected to the AC side of the bidirectional inverter 18, which can connect not only the 100 V AC specific load 41 A but also the AC 200 V specific load 41 B. It plays a role as an interface means for converting into a phase 3-wire wiring path.

  Here, when the controller 19 determines that power is supplied from the power supply system 2 to the power receiving equipment 4 based on the detection signal from the current transformer 6, the power storage system 1 is connected to the power supply system 2. Therefore, the first switching means 11, the second switching means 12, and the fourth switching means 14 are set to "ON", that is, closed, and the third switching means 13 is controlled to be switched "OFF", that is, opened. For example, when it is determined that power is not supplied from the power supply system 2 to the power receiving facility 4, the first switching unit 11 and the first switching unit 11 are operated in order to operate the power storage system 1 independently of the power supply system 2. 2 The switching means 12 is set to “OFF”, that is, opened, the third switching means 13 is controlled to be turned “ON”, ie, closed, and the fourth switching means 14 is set to “ON” when the storage battery 9 is not fully charged. " To KazuSatoshi closed state, at the time of full charge of the battery 9 to control switch to "off" or open state. Whether or not the storage battery 9 is fully charged is determined by the controller 19 in the inverter unit 8 based on the battery voltage, the charging rate (SOC), etc. of the storage battery 9. When the storage battery 9 is fully charged, the fourth switching means 14 is “turned off”, that is, opened, because the generated power of the photovoltaic power generation facility 21 is larger than the power consumption of the specific load 41A and the specific load 41B, and the storage battery 9 This is for avoiding the danger that the voltage of the wiring line rises and becomes dangerous when the bidirectional inverter 18 cannot be charged due to full charge. Here, an example in which it is determined that the power is supplied from the power supply system 2 based on the detection signal from the current transformer 6 is shown. However, the voltage of the power feeding path 31 is measured in the inverter unit 8, and the voltage detection signal is used. You may judge. In addition, although it is determined by the inverter unit 8 whether or not the battery is fully charged, it may be determined by a charge permission signal of the storage battery 9.

  As shown in FIG. 6, when the power storage system 1 in the second system configuration is connected to the grid, the power storage system 1 is connected to the power supply system 2 by the first switching unit 11 and the second switching unit 12 that are closed. Is done. Therefore, the system power from the power supply system 2 is supplied to the general loads 5A and 5B connected to the power supply path 3, and the specific loads 41A and 41B connected to the third wiring path 33 via the second switching means 12. To be supplied. Moreover, since the power storage system 1 is linked to the photovoltaic power generation facility 21 by the fourth switching means 14 in the closed state, the power supply system 2 to the power receiving facility 4 can be used while the solar battery 22 generates power. To supplement the grid power, AC power from the photovoltaic power generation facility 21 is supplied to the specific loads 41A and 41B via the fourth switching means 14, and further to the general loads 5A and 2A via the second switching means 12. Also supplied to 5B.

  Even in the second system configuration, when the power storage system 1 is connected to the grid, the peak shift or peak cut as described above is performed by the inverter unit 8. With such control, while the charge control signal is sent from the controller 19 to the bidirectional inverter 18, the grid power from the power supply system 2 passes through the first switching means 11 and the AC from the photovoltaic power generation facility 21. Electric power is applied to the bidirectional inverter 18 via the fourth switching means 14, the second switching means 12 and the first switching means 11 in order, and the DC power converted here is supplied to the storage battery 9, While charging the storage battery 9, while a discharge control signal is sent from the controller 19 to the bidirectional inverter 18, the DC power from the storage battery 9 is converted into AC power by the bidirectional inverter 18 and received from the power system 2. The supplemented AC power is supplied to the general loads 5A and 5B via the first switching means 11 so as to supplement the system power to the facility 4, and further the second switching means 12 is provided. Derived to identify the load 41A, also supplied to 41B. When the controller 19 detects a reverse power flow using the detection signal from the current transformer 6, the output of the bidirectional inverter 18 is connected to the power supply system 2 by turning the first switching means 11 off. Reverse tide can be completely prevented. That is, the power stored in the storage battery 9 can be prevented from flowing into the power supply system 2.

  Further, as shown in FIG. 7, during the self-sustaining operation of the power storage system 1 in the second system configuration, the power storage system 1 is disconnected from the power supply system 2 by the first switching means 11 and the second switching means 12 that are open. It is. In this case, although the power supply from the power supply system 2 to the general loads 5A and 5B is cut off, the inverter unit 8 uses the storage battery 9 and the photovoltaic power generation facility 21 to supply power to the specific loads 41A and 41B. In normal times when 9 is not fully charged, the fourth switching means 14 is switched to the closed state so that the AC power from the photovoltaic power generation equipment 21 is supplied to the specific loads 41A and 41B, and when the AC power has a margin, the storage battery further On the other hand, when the storage battery 9 is fully charged, the DC power from the storage battery 9 is converted into AC power by the bidirectional inverter 18 by sending a discharge control signal from the controller 19 to the bidirectional inverter 18. The converted AC power is supplied to the specific loads 41A and 41B via the third switching means 13 in the closed state.

  Thus, in the second system configuration, the AC power from the photovoltaic power generation facility 21 is closed so that it can be supplied to the general loads 5A and 5B and the specific loads 41A and 41B when the grid is connected to the power supply system 2. At the time of self-sustained operation disconnected from the grid 2, the battery 9 is opened or closed according to the state of charge of the storage battery 9, so that AC power from the photovoltaic power generation facility 21 can be supplied to the specific loads 41A and 41B at least in the closed state. The fourth switching means 14 is added to the power storage system 1 having the first system configuration. Moreover, the AC power generated by the photovoltaic power generation facility 21 is connected by connecting the output of the AC 200V single-phase three-wire of the PCS 23 and the input / output of the AC 200V single-phase two-wire of the bidirectional inverter 18 by adding the transformer 16. The storage battery 9 can be charged. Furthermore, by adding this transformer 16, the output of the bidirectional inverter 18 is converted into an AC 200V single-phase three-wire, so that the power charged in the storage battery 9 is converted into a specific load 41A (for example, lighting equipment or broadcast) of AC 100V. Equipment) and an AC 200V specific load 41B (for example, a commercial refrigerator or a commercial air conditioner). Thereby, when the photovoltaic power generation facility 21 combining the solar cell 22 and the PCS 23 is introduced first or later, only the fourth switching means 14 and the transformer 16 are added to the existing power storage system 1. Thus, it is possible to easily connect such an inexpensive commercial product or existing solar power generation equipment 21 to the power storage system 1 without major modification, and the cost as the power storage system 1 can be reduced. In the second system configuration, since the transformer 16 is added, power can be supplied not only to the specific load 41A of AC 100V but also to the specific load 41B of AC 200V from the solar power generation facility 21 during the self-sustaining operation. .

  Next, regarding the third system configuration, FIG. 9 shows the configuration of the power storage system 1 and the operating state of each part during grid connection, and FIG. 10 shows the configuration of the power storage system 1 and the operating state of each part during self-sustained operation. FIG. 11 shows a list of operation states of the first switching means 11 to the fifth switching means 15.

  In a third system configuration in which a solar power generation facility 21 is provided and power is sold from the solar power generation facility 21 to the power supply system 51, the transformer 16 and the fourth switching means 14 are provided inside the system body 7, and the system Outside the main body 7, the solar power generation equipment 21 is connected to the solar power generation connection terminal 17 of the system main body 7 via the fifth wiring path 35 and connected to the power supply system 51 via the sixth wiring path 36. In addition, the sixth switching path 15 is equipped with the fifth switching means 15. The functions of the transformer 16 and the fourth switching means 14 are as described in the second system configuration. The fourth switching means 14 here further sells power from the solar cell equipment 21 to the power supply system 51. When the power source is in the open state, the switching power is controlled to prevent the discharge power from the storage battery 9 from flowing backward to the power supply system 51 via the solar power generation connection terminal 17.

  Here, when the controller 19 determines that power is supplied from the power supply system 2 to the power receiving equipment 4 based on the detection signal from the current transformer 6, the power storage system 1 is connected to the power supply system 2. In order to achieve this, the first switching means 11, the second switching means 12 and the fifth switching means 15 are "on" or closed, and the third switching means 13 and the fourth switching means 14 are switched to "off" or open. On the other hand, when it is determined that power is not supplied from the power supply system 2 to the power receiving facility 4 due to a power failure or the like, the power storage system 1 is operated independently without depending on the power supply system 2. The first switching means 11, the second switching means 12 and the fifth switching means 15 are set to "OFF", that is, open, the third switching means 13 is set to "ON", ie, closed, and the fourth switching means 14 is Storage battery 9 Mitsuru is the normal time that has not been charged in "containing" or closed state, at the time of full charge of the battery 9 to control switch to "off" or open state. Again, the controller 19 determines whether or not the storage battery 9 is fully charged based on the battery voltage, the charging rate (SOC), etc. of the storage battery 9 in the inverter unit 8. Here, an example in which it is determined that the power is supplied from the power supply system 2 based on the detection signal from the current transformer 6 is shown. However, the voltage of the power feeding path 31 is measured in the inverter unit 8, and the voltage detection signal is used. You may judge. In addition, although it is determined by the inverter unit 8 whether or not the battery is fully charged, it may be determined by a charge permission signal of the storage battery 9.

  As shown in FIG. 9, when the power storage system 1 in the third system configuration is connected to the grid, the power storage system 1 is connected to the power supply system 2 by the first switching unit 11 and the second switching unit 12 that are in the closed state. Is done. Therefore, the system power from the power supply system 2 is supplied to the general loads 5A and 5B connected to the power supply path 3, and the specific loads 41A and 41B connected to the third wiring path 33 via the second switching means 12. To be supplied. In addition, while the fifth switching means 15 in the closed state generates power with the solar battery 22, the AC power from the photovoltaic power generation facility 21 is supplied to the power system 51 for power sale, while being opened. By the fourth switching means 14 in the state, the photovoltaic power generation facility 21 is disconnected from the system main body 7, and the discharge power from the storage battery 9 flows backward to the power system 51 via the solar power generation connection terminal 17. Prevent completely. As a result, the power supply system 51 is not adversely affected, and the power supply system 51 managed by the power company and the solar power generation facility 21 can be easily connected to perform power sale.

  Even in the third system configuration, when the power storage system 1 is connected to the grid, the above-described peak shift or peak cut is performed by the inverter unit 8. With such control, while a charge control signal is sent from the controller 19 to the bidirectional inverter 18, the system power from the power supply system 2 is applied to the bidirectional inverter 18 via the first switching means 11, While the converted DC power is supplied to the storage battery 9 to charge the storage battery 9, the DC power from the storage battery 9 is supplied while the discharge control signal is sent from the controller 19 to the bidirectional inverter 18. The AC power is converted into AC power by the bidirectional inverter 18, and the converted AC power is supplied to the general loads 5 </ b> A and 5 </ b> B via the first switching means 11 so as to supplement the system power from the power system 2 to the power receiving facility 4. In addition, it is also supplied to the specific loads 41A and 41B via the second switching means 12. When the controller 19 detects a reverse power flow using the detection signal from the current transformer 6, the output of the bidirectional inverter 18 is connected to the power supply system 2 by turning the first switching means 11 off. Reverse tide can be completely prevented. That is, the power stored in the storage battery 9 can be prevented from flowing into the power supply system 2.

  Further, as shown in FIG. 10, during the self-sustaining operation of the power storage system 1 in the third system configuration, the power storage system 1 is disconnected from the power supply system 2 by the first switching means 11 and the second switching means 12 that are in the open state. It is. In this case, although the power supply from the power supply system 2 to the general loads 5A and 5B is cut off, the inverter unit 8 supplies power to the specific loads 41A and 41B from the storage battery 9 and the photovoltaic power generation equipment 21. The 5 switching means 15 is switched to the open state to stop selling power to the power supply system 51, and at the normal time when the storage battery 9 is not fully charged, the fourth switching means 14 is switched to the closed state to When the AC power from the power source 21 is supplied to the specific loads 41A and 41B and there is a margin in the AC power, the storage battery 9 is further charged. On the other hand, when the storage battery 9 is fully charged, When the power consumption is lower than 41A and 41B, the controller 19 sends a discharge control signal to the bidirectional inverter 18 so that the DC power from the storage battery 9 is bidirectional. Is converted into AC power by the inverter 18, AC power that converts the third switching means 13 specific load 41A by way of a closed, is supplied to 41B.

  Thus, in the third system configuration, in addition to the characteristics of the second system configuration described above, the fifth switching means 15 is added between the solar power generation equipment 21 and the power supply system 51 outside the system main body 7, and the system When the controller 19 of the inverter system 8 provided inside the main body 7 controls the opening and closing of the fifth switching unit 15 to switch the fifth switching unit 15 to the closed state, the photovoltaic power generation facility 21 generates power. It becomes possible to supply the generated power to the separate power supply 51 for power sale. That is, here, the added fifth switching means 15 is controlled to be opened / closed on the power storage system 1 side, so that whether or not to sell power from the photovoltaic power generation facility 21 to the power supply system 51 is arbitrarily determined without adding an external controller. Can be selected.

  Further, in the third system configuration, the fourth switching means 14 added in the second system configuration is switched, so that the photovoltaic power generation facility 21 is disconnected from the system body 7 and the discharge power from the storage battery 9 is connected to the photovoltaic power generation. It is possible to completely prevent a reverse power flow to the power supply system 51 via the service terminal 17. As a result, the power supply system 51 is not adversely affected, and the power supply system 51 managed by the power company and the solar power generation facility 21 can be easily connected to perform power sale.

  As described above, in the present embodiment, the system power supplied from the power supply system 2 by controlling the bidirectional inverter 18 connected between the power supply system 2 and the storage battery 9 when the system is connected to the power supply system 2. In the self-sustained operation disconnected from the power supply system 2, the DC power from the storage battery 9 is converted into AC power by the bidirectional inverter 18, and the AC power is converted into a specific load 41A as a load. , 41B, fourth switching means that is controlled to be opened and closed so that AC power from the photovoltaic power generation facility 21 can be supplied to the specific loads 41A, 41B during the grid connection or the independent operation. 14 and the third wiring path 33 to which the specific loads 41A and 41B are connected on the AC side of the bidirectional inverter 18 as a converter for converting from a single-phase two-wire system to a single-phase three-wire system. The lance 16 has a configuration obtained by adding to the power storage system 1.

  In this case, if the fourth switching means 14 and the transformer 16 are added to the existing power storage system 1, the solar power generation facility 21 that outputs AC power combining the solar cell 22 and the PCS 23 without major modification is provided. Therefore, it is possible to easily connect to the power storage system 1, and the cost as the power storage system 1 can be reduced. Further, by adding the transformer 16 to the existing power storage system 1, the discharge power from the storage battery 9 is connected to the third wiring path 33 of the AC 200 V single-phase three-wire system with the configuration in which the photovoltaic power generation equipment 21 is connected. It is possible to supply various specific loads 41A and 41B that can be connected.

  That is, it is possible to connect an inexpensive commercial product or the existing photovoltaic power generation equipment 21 without adding a large-scale modification only by adding the fourth switching means 14 and the transformer 16 to the existing power storage system 1. In addition to reducing the cost of the power storage system 1, power is supplied to the various specific loads 41A and 41B from the photovoltaic power generation equipment 21 and the storage battery 9 via the AC 200V single-phase three-wire third wiring path 33. it can.

  And this adds the 4th switching means 14 and the transformer 16 to the electric power storage system 1, and controls the opening and closing of the 4th switching means 14 so that the alternating current power from the solar power generation equipment 21 can be supplied to specific load 41A, 41B. Then, the transformer 16 is added to the power storage system 1, and the third wiring path 33 to which the specific loads 41A and 41B are connected on the AC side of the bidirectional inverter 18 is changed from a single-phase two-wire system to a single-phase three-wire system. It can also be realized by the control method of the power storage system 1 that converts to

  Further, the power storage system 1 of the present embodiment includes a fifth switching means 15 that is controlled to be opened and closed so that AC power generated from the solar power generation facility 21 can be supplied to the power supply system 51 for power sale. 7 is further added to the outside.

  In this case, with the configuration in which the fifth switching unit 15 is only added, the fifth switching unit 15 is controlled to be opened and closed on the power storage system 1 side, so that the power can be supplied from the photovoltaic power generation facility 21 without adding an external controller. Power can be sold to the system 51.

  And this adds the 5th switching means 15 to the electric power storage system 1, and opens and closes the 5th switching means 15 so that the alternating current power from the photovoltaic power generation equipment 21 can be supplied to the power supply system 51 for power sale. This can also be realized by the control method of the power storage system 1 to be controlled.

  In addition, the power storage system 1 of the present embodiment is configured to prevent reverse power flow of discharge power from the storage battery 9 to the power supply system 51 by switching control of the fourth switching means 14.

  In this case, the reverse flow of the discharge power from the storage battery 9 to the power supply system 51 can be completely prevented by opening and closing the fourth switching means 14 using the added fourth switching means 14. Therefore, it is possible to easily connect the power supply system 51 and the solar power generation facility 21 without selling the power supply system 51 adversely.

  This can also be realized by the control method of the power storage system 1 that switches and controls the fourth switching means 14 in order to prevent the reverse flow of the discharge power from the storage battery 9.

  The power storage system 1 of the present embodiment has a first system configuration in which the fourth switching unit 14, the fifth switching unit 15, and the transformer 16 are not provided when the solar power generation facility 21 is not connected. When the solar power generation facility 21 is connected but no power is sold from the solar power generation facility 21, the second system is equipped with the fourth switching means 14 and the transformer 16 and not the fifth switching means 15. When the solar power generation facility 21 is connected and the power sale from the solar power generation facility 21 is performed, a third switching unit 14, a fifth switching unit 15, and a transformer 16 are provided. The system configuration has a configuration that can be expanded in stages.

  In this case, the power storage system 1 is gradually expanded to the first system configuration, the second system configuration, or the third system configuration according to the overall system configuration, and the expanded fourth switching unit 14 and fifth switching are expanded. By switching and controlling the means 15 on the power storage system 1 side, it is possible to eliminate major modifications of the power storage system 1 due to the presence / absence of the photovoltaic power generation facility 21 and the presence / absence of power sale of the solar power generation facility 21, It becomes possible to reduce the cost at the time of system construction as the power storage system 1.

  In addition, this invention is not limited to the said Example, A various change, correction, and improvement are possible in the range which does not deviate from the meaning of this invention. For example, each of the first switching unit 11 to the fifth switching unit 15 described above is a mechanical switch, but another unit that exhibits an equivalent function may be used. Further, in this embodiment, the power supply system 2 and the power supply system 51 are separately illustrated for the sake of explanation, but this shows only the power supply systems with different commercial contracts. Can be regarded as one power supply system.

DESCRIPTION OF SYMBOLS 1 Power storage system 2,51 Power supply system 9 Storage battery 18 Bidirectional inverter 14 4th switching means (1st switching means)
15 Fifth switching means (second switching means)
16 Transformer
33 Third wiring path (wiring path)
41A, 41B Specific load (load)

Claims (4)

Controlling a bidirectional inverter connected between the power supply system and the storage battery during grid connection to the power supply system, while performing peak shift and peak cut of power supplied from the power supply system, the power supply In the self-sustaining operation separated from the system, in the power storage system that converts the DC power from the storage battery into AC power by the bidirectional inverter, and supplies the AC power to the load,
First switching means that is controlled to be opened and closed so that AC power from the photovoltaic power generation facility can be supplied to the load;
A power storage system comprising a converter for converting a wiring path to which the load is connected from a single-phase two-wire system to a single-phase three-wire system on the AC side of the bidirectional inverter.   The power storage system according to claim 1, further comprising a second switching unit that is controlled to be opened and closed so that AC power from the photovoltaic power generation facility can be supplied to the power supply system for power sale.   The power storage system according to claim 2, wherein the first switching means is controlled to prevent reverse power flow of discharge power from the storage battery. If the solar power generation equipment is not connected, the first switching means, the second switching means, and the first system configuration not equipped with the converter,
When the solar power generation equipment is connected but no power is sold from the solar power generation equipment, the first switching means and the converter are provided, and the second switching means is not provided. Two system configuration,
When connecting the solar power generation equipment and selling power from the solar power generation equipment, a third switch equipped with the first switching means, the second switching means, and the converter is provided. The power storage system according to claim 2 , wherein the system configuration is a configuration that can be expanded in stages.

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