Power conditioner device and method for controlling the same

Abstract

To reduce unnecessary power consumption of a power conditioner in a power system.SOLUTION: A power conditioner 10 for receiving output of a solar cell 20 is connected to a system power supply 50 and a load 40, and is also connected to storage batteries 31 and 33. In the power conditioner 10, a control unit 13 stops switching operations of an inverter circuit 12, when the amount of charge of storage batteries 31 and 33 has reached an upper threshold with no output of the solar cell 20 in the time zone when the storage batteries 31 and 33 are supposed to be charged by setting of a user.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a power conditioner that receives the output of a solar cell, is connected to a system power supply and a load, and is also connected to a storage battery. [Background technology]

[0002] Patent Document 1 discloses the configuration of a charging / discharging device that converts stored power and reliably supplies it to a load while avoiding reverse power flow to the power grid. Patent Document 1 also shows that when power is restored from a power outage, the inverter is stopped by a command from a control unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-51909 Summary of the Invention [Problem to be solved by the invention]

[0004] A power conditioner is equipped with an inverter circuit that converts DC power to AC power. It receives solar cell output, is connected to a grid power supply and a load, and is also connected to a storage battery. Even when there is no solar cell output and the storage battery is not charging or discharging, the power conditioner maintains its internal DC voltage. In this situation, the power conditioner operates the inverter circuit, which results in unnecessary power consumption in the inverter circuit and its driver IC.

[0005] The present invention aims to reduce wasteful power consumption in a power conditioner that receives the output of a solar cell, is connected to a system power supply and a load, and is also connected to a storage battery. [Means for solving the problem]

[0006] In one aspect of the present invention, a power conditioner receives the output of a solar cell, is connected to a system power supply and a load, and is also connected to a storage battery, and is equipped with an inverter circuit that converts DC power to AC power, and at least a control unit that controls the inverter circuit, and converts DC power output from the solar cell or the storage battery into AC power by the inverter circuit and outputs it to the system power supply or the load, and converts AC power input from the system power supply into DC power by the inverter circuit and outputs it to the storage battery, and the control unit stops the switching operation of the inverter circuit when the charge amount of the storage battery has reached an upper limit threshold when there is no output from the solar cell during a time period specified by a user for charging the storage battery.

[0007] According to this configuration, in the power conditioner, the control unit stops the switching operation of the inverter circuit when the charge level of the storage battery reaches the upper threshold in a time period specified by the user for charging the storage battery with no output from the solar cell. This makes it possible to stop the switching operation of the inverter circuit when charging of the storage battery is not required, thereby reducing unnecessary power consumption in the power conditioner.

[0008] Another aspect of the present invention is a power conditioner that receives the output of a solar cell, is connected to a system power supply and a load, and is also connected to a storage battery, and includes an inverter circuit that converts DC power to AC power, and at least a control unit that controls the inverter circuit, and converts DC power output from the solar cell or the storage battery into AC power by the inverter circuit and outputs it to the system power supply or the load, and converts AC power input from the system power supply into DC power by the inverter circuit and outputs it to the storage battery, and the control unit stops the switching operation of the inverter circuit when the charge amount of the storage battery has reached a lower threshold value and there is no output from the solar cell during a time period in which discharging of the storage battery is specified by a user setting.

[0009] According to this configuration, in the power conditioner, the control unit stops the switching operation of the inverter circuit when the charge level of the storage battery reaches a lower threshold in a time period designated by the user for discharging the storage battery with no solar cell output. This makes it possible to stop the switching operation of the inverter circuit when discharging the storage battery is not required, thereby reducing unnecessary power consumption in the power conditioner.

[0010] Another aspect of the present invention is a control method for a power conditioner that receives output from a solar cell, is connected to a system power supply and a load, and is also connected to a storage battery, wherein the power conditioner has an inverter circuit that converts DC power to AC power, and converts DC power output from the solar cell or the storage battery into AC power using the inverter circuit and outputs it to the system power supply or the load, and also converts AC power input from the system power supply into DC power using the inverter circuit and outputs it to the storage battery, and the control method includes a step of stopping the switching operation of the inverter circuit when the charge amount of the storage battery has reached an upper limit threshold value and there is no output from the solar cell during a time period in which charging of the storage battery is specified by a user setting.

[0011] According to this configuration, in the power conditioner, if the charge level of the storage battery reaches the upper threshold when there is no output from the solar cell during a time period when the user has specified that the storage battery be charged, the switching operation of the inverter circuit is stopped. This makes it possible to stop the switching operation of the inverter circuit when charging of the storage battery is not required, thereby reducing unnecessary power consumption in the power conditioner.

[0012] Another aspect of the present invention is a control method for a power conditioner that receives output from a solar cell, is connected to a system power supply and a load, and is also connected to a storage battery, wherein the power conditioner has an inverter circuit that converts DC power to AC power, and converts DC power output from the solar cell or the storage battery into AC power by the inverter circuit and outputs it to the system power supply or the load, and converts AC power input from the system power supply into DC power by the inverter circuit and outputs it to the storage battery, and the control method includes a step of stopping the switching operation of the inverter circuit when the charge level of the storage battery has reached a lower threshold value and there is no output from the solar cell during a time period in which discharging of the storage battery is specified by a user setting.

[0013] According to this configuration, in the power conditioner, if the charge level of the storage battery reaches a lower threshold in a time period designated by the user for discharging the storage battery and there is no output from the solar cell, the switching operation of the inverter circuit is stopped. This makes it possible to stop the switching operation of the inverter circuit when discharging the storage battery is not required, thereby reducing unnecessary power consumption in the power conditioner.

[0014] In each of the above aspects, the storage battery is at least one of a stationary storage battery and a vehicle storage battery connected to the power conditioner via a V2H (Vehicle to Home) stand. [Effects of the Invention]

[0015] According to the present invention, it is possible to reduce unnecessary power consumption in a power conditioner that receives the output of a solar cell, is connected to a system power supply and a load, and is also connected to a storage battery. [Brief explanation of the drawings]

[0016] [Figure 1] Configuration example of power system according to the embodiment [Figure 2] Example of operation of power system according to embodiment [Figure 3] Another example of operation of the power system according to the embodiment DETAILED DESCRIPTION OF THE INVENTION

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. The following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the present invention, its scope of application, or its uses.

[0018] (Embodiment) Fig. 1 shows an example of the configuration of a power system according to an embodiment. In the power system of Fig. 1, a power conditioning subsystem (PCS) 10 receives the output of a photovoltaic (PV) 20 and is connected to a load 40 and a grid power supply 50. The power conditioner 10 is also connected to a storage battery. In the power system of Fig. 1, the power conditioner 10 is connected to a stationary storage battery 31 and a vehicle storage battery 33 mounted on a vehicle as storage batteries. The stationary storage battery 31 is directly connected to the power conditioner 10, and the vehicle storage battery 33 is connected to the power conditioner 10 via a vehicle-to-home (V2H) stand 32.

[0019] The power conditioner 10 includes a DC / DC converter 11 that performs voltage conversion of DC power, an inverter circuit 12 that converts DC power to AC power, and a control unit 13 that controls the circuit including the inverter circuit 12. Other components are not shown in the figure.

[0020] The power conditioner 10 converts the voltage of the DC power output from the solar cell 20 using the DC / DC converter 11, converts the voltage-converted DC power into AC power using the inverter circuit 12, and outputs it to the load 40 or the system power supply 50. The power conditioner 10 also converts AC power input from the system power supply 50 into DC power using the inverter circuit 12, outputs it to the stationary storage battery 31 or the vehicle storage battery 33, and charges the stationary storage battery 31 or the vehicle storage battery 33. The power conditioner 10 also converts the voltage of the DC power output from the solar cell 20 using the DC / DC converter 11, and outputs the voltage-converted DC power to the stationary storage battery 31 or the vehicle storage battery 33, and charges the stationary storage battery 31 or the vehicle storage battery 33. In addition, the power conditioner 10 discharges the stationary storage battery 31 or the vehicle storage battery 33, converts the DC power output from the stationary storage battery 31 or the vehicle storage battery 33 into AC power using the inverter circuit 12, and outputs it to the load 40 or the system power supply 50.

[0021] 1, for example, even when the solar cell 20 is not generating power and the stationary storage battery 31 and the vehicle storage battery 33 are not charging or discharging, the power conditioner 10 continues to operate to maintain the internal DC voltage. During this time, the inverter circuit 12 performs a switching operation, which causes power consumption in the inverter circuit 12 and its driving IC.

[0022] In this embodiment, when the solar cell 20 is not generating power and the stationary storage battery 31 and the vehicle storage battery 33 are not performing charging or discharging operations, the switching operation of the inverter circuit 12 is stopped. This makes it possible to reduce unnecessary power consumption in the power conditioner 10.

[0023] 2 shows an example of the operation of the power system according to the embodiment. Here, it is assumed that a time period for charging the stationary storage battery 31 and the vehicle storage battery 33 is specified by a user, and the operation is performed during that time period.

[0024] First, the power conditioner 10 performs a charging operation on the stationary storage battery 31. As this charging operation proceeds, the SOC (State Of Charge) of the stationary storage battery 31 gradually increases. The SOC is an example of an index that indicates the amount of charge in a storage battery. The SOC of the stationary storage battery 31 eventually reaches an upper limit value for use. At this time, the power conditioner 10 stops the charging operation on the stationary storage battery 31.

[0025] Next, the power conditioner 10 performs a charging operation on the vehicle storage battery 33 via the V2H stand 32. The SOC of the vehicle storage battery 33 eventually reaches an upper limit value for use. At this time, the power conditioner 10 stops the charging operation on the vehicle storage battery 33.

[0026] Meanwhile, suppose that the output of the solar cell 20 gradually decreases during the charging operation of the stationary storage battery 31 and the vehicle storage battery 33. Then, when there is no output from the solar cell 20 for a certain period of time after the charging operation of the stationary storage battery 31 and the vehicle storage battery 33 is stopped, the power conditioner 10 transitions to a standby state. During this standby period, the control unit 13 stops the switching operation of the inverter circuit 12. This makes it possible to reduce unnecessary power consumption in the power conditioner 10.

[0027] Thereafter, when the conditions for the power system to enter a standby state are no longer satisfied, the power conditioner 10 returns to an operating state, and the control unit 13 resumes the switching operation of the inverter circuit 12. For example, when a time period for charging set by the user ends or when output from the solar cell 20 is generated, the control unit 13 resumes the switching operation of the inverter circuit 12. Furthermore, for example, when the power conditioner 10 starts to be connected to the grid power supply 50 by a user operation, the control unit 13 resumes the switching operation of the inverter circuit 12.

[0028] 3 shows another example of the operation of the power system according to the embodiment. Here, it is assumed that a time period for discharging the stationary storage battery 31 and the vehicle storage battery 33 is specified by a user, and this operation is performed during that time period.

[0029] First, the power conditioner 10 performs a discharge operation on the stationary storage battery 31. As this discharge operation occurs, the SOC (State Of Charge) of the stationary storage battery 31 gradually decreases. The SOC of the stationary storage battery 31 eventually reaches a lower limit value for use. At this time, the power conditioner 10 stops the discharge operation on the stationary storage battery 31.

[0030] Next, the power conditioner 10 performs a discharge operation on the vehicle storage battery 33 via the V2H stand 32. The SOC of the vehicle storage battery 33 eventually reaches a lower limit value for use. At this time, the power conditioner 10 stops the discharge operation on the vehicle storage battery 33.

[0031] Meanwhile, suppose that the output of the solar cell 20 gradually decreases during the discharging operation of the stationary storage battery 31 and the vehicle storage battery 33. Then, when there is no output from the solar cell 20 for a certain period of time after the discharging operation of the stationary storage battery 31 and the vehicle storage battery 33 is stopped, the power conditioner 10 transitions to a standby state. During this standby period, the control unit 13 stops the switching operation of the inverter circuit 12. This makes it possible to reduce unnecessary power consumption in the power conditioner 10.

[0032] Thereafter, when the conditions for the power system to enter a standby state are no longer satisfied, the power conditioner 10 returns to an operating state, and the control unit 13 resumes the switching operation of the inverter circuit 12. For example, when the time period for discharging set by the user ends or when output from the solar cell 20 occurs, the control unit 13 resumes the switching operation of the inverter circuit 12. Furthermore, for example, when the power conditioner 10 starts to be connected to the grid power supply 50 by a user operation, the control unit 13 resumes the switching operation of the inverter circuit 12.

[0033] As described above, according to the present embodiment, in the power conditioner 10, the control unit 13 stops the switching operation of the inverter circuit 12 when the charge amounts of the stationary storage battery 31 and the vehicle storage battery 33 reach an upper threshold value with no output from the solar cell 20 during a time period designated by the user for charging the stationary storage battery 31 and the vehicle storage battery 33. Also, in the power conditioner 10, the control unit 13 stops the switching operation of the inverter circuit 12 when the charge amounts of the stationary storage battery 31 and the vehicle storage battery 33 reach a lower threshold value with no output from the solar cell 20 during a time period designated by the user for discharging the stationary storage battery 31 and the vehicle storage battery 33. This makes it possible to stop the switching operation of the inverter circuit 12 when charging or discharging the stationary storage battery 31 and the vehicle storage battery 33 is not required, thereby reducing unnecessary power consumption in the power conditioner 10.

[0034] In the above-described operation example, after a certain time has elapsed since the conditions for entering the standby state were satisfied, the power conditioner 10 transitions to the standby state, and the control unit 13 stops the switching operation of the inverter circuit 12. However, it is not necessarily necessary to wait a certain time after the conditions for entering the standby state are satisfied. For example, the power conditioner 10 may transition to the standby state, and the control unit 13 may stop the switching operation of the inverter circuit 12, immediately after the conditions for entering the standby state are satisfied.

[0035] In the above-described operation example, other indicators indicating the charge amount of the storage battery may be used instead of the SOC. The upper and lower limits for the charge amount may be values ​​determined based on the specifications of the storage battery, or may be values ​​set by the user.

[0036] (Other configuration examples) In the power system according to the above embodiment, the power conditioner 10 is connected to both the stationary storage battery 31 and the vehicle storage battery 33 as storage batteries, but the present invention is not limited to this.

[0037] For example, the present disclosure is also applicable to a power system in which only the stationary storage battery 31 as a storage battery is connected to the power conditioner 10. In this case, the control unit 13 may stop the switching operation of the inverter circuit 12 when the charge amount of the stationary storage battery 31 reaches an upper limit threshold while there is no output from the solar cell 20 during a charging time period of the stationary storage battery 31, or when the charge amount of the stationary storage battery 31 reaches a lower limit threshold while there is no output from the solar cell 20 during a discharging time period of the stationary storage battery 31.

[0038] Alternatively, the present disclosure may also be applied to a power system in which only the vehicle storage battery 33 as a storage battery is connected to the power conditioner 10. In this case, the control unit 13 may stop the switching operation of the inverter circuit 12 when the charge amount of the vehicle storage battery 33 reaches an upper threshold value with no output from the solar cell 20 during a charging time period of the vehicle storage battery 33, or when the charge amount of the vehicle storage battery 33 reaches a lower threshold value with no output from the solar cell 20 during a discharging time period of the vehicle storage battery 33. [Industrial Applicability]

[0039] INDUSTRIAL APPLICABILITY The present invention is useful for reducing the power consumption of a power conditioner in a power system that includes a power conditioner that receives the output of a solar cell, is connected to a system power supply and a load, and is also connected to a storage battery. [Explanation of symbols]

[0040] 10 Power Conditioner 12 Inverter circuit 13 Control Unit 20 Solar Cells 31 Stationary storage battery 32 V2H Stand 33 Vehicle battery 40 Load 50 Grid power supply

Claims

1. A power conditioner that receives an output from a solar cell, is connected to a system power supply and a load, and is also connected to a storage battery, an inverter circuit that converts DC power and AC power; a control unit that controls at least the inverter circuit, DC power output from the solar cell or the storage battery is converted by the inverter circuit into AC power and output to the system power supply or the load, and AC power input from the system power supply is converted by the inverter circuit into DC power and output to the storage battery, The control unit When the charge amount of the storage battery reaches an upper limit threshold value in a time period designated by a user for charging the storage battery, with no output from the solar cell, the switching operation of the inverter circuit is stopped. Power conditioner.

2. A power conditioner that receives an output from a solar cell, is connected to a system power supply and a load, and is also connected to a storage battery, an inverter circuit that converts DC power and AC power; a control unit that controls at least the inverter circuit, DC power output from the solar cell or the storage battery is converted by the inverter circuit into AC power and output to the system power supply or the load, and AC power input from the system power supply is converted by the inverter circuit into DC power and output to the storage battery, The control unit When the charge amount of the storage battery reaches a lower limit threshold in a time period in which the storage battery is designated to be discharged by a user and there is no output from the solar cell, the switching operation of the inverter circuit is stopped. Power conditioner.

3. The power conditioner according to claim 1 or 2, The storage battery is At least one of a stationary storage battery and a vehicle storage battery connected to the power conditioner via a V2H (Vehicle to Home) stand. Power conditioner.

4. A control method for a power conditioner that receives an output from a solar cell, is connected to a system power supply and a load, and is also connected to a storage battery, comprising: The power conditioner comprises: An inverter circuit is provided for converting DC power to AC power, DC power output from the solar cell or the storage battery is converted by the inverter circuit into AC power and output to the system power supply or the load, and AC power input from the system power supply is converted by the inverter circuit into DC power and output to the storage battery, The control method includes: and stopping the switching operation of the inverter circuit when the charge amount of the storage battery reaches an upper limit threshold in a time period in which charging of the storage battery is designated by a user in a state in which there is no output from the solar cell. How to control a power conditioner.

5. A control method for a power conditioner that receives an output from a solar cell, is connected to a system power supply and a load, and is also connected to a storage battery, comprising: The power conditioner comprises: An inverter circuit is provided for converting DC power to AC power, DC power output from the solar cell or the storage battery is converted by the inverter circuit into AC power and output to the system power supply or the load, and AC power input from the system power supply is converted by the inverter circuit into DC power and output to the storage battery, The control method includes: and stopping the switching operation of the inverter circuit when the charge amount of the storage battery reaches a lower limit threshold in a time period in which the storage battery is designated to be discharged by a user in a state in which there is no output from the solar cell. How to control a power conditioner.

6. The power conditioner control method according to claim 4 or 5, The storage battery is At least one of a stationary storage battery and a vehicle storage battery connected to the power conditioner via a V2H (Vehicle to Home) stand. How to control a power conditioner.

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