JP6358376B2 - Storage battery conversion device, power supply system, and power supply control method - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a storage battery conversion device, a power supply system, and a power supply control method, and in particular, a storage battery conversion device that controls DC power supply via a line by controlling charge / discharge of the storage battery, a power supply system, and power. The present invention relates to a supply control method.

  Conventionally, in a power system that includes a solar cell and a power conditioner that converts the DC power of the solar cell into AC power and outputs it to a load, a technique for charge / discharge control of the power of the solar cell with respect to the storage battery has been proposed. (See Patent Document 1). Specifically, a bidirectional DC / DC converter is interposed between the DC bus line in the power conditioner and the storage battery, the line voltage in the DC bus line is monitored, and the line voltage is in a certain range. The bi-directional DC / DC converter is PWM-controlled to control charging to the storage battery and discharging to the DC bus line.

JP2012-161189A

  However, in the technique described in Patent Document 1, there is a risk that the life of the storage battery may be shortened by increasing the repetition frequency of charging and discharging of the storage battery.

  Accordingly, an object of the present invention is to provide a storage battery conversion device, a power supply system, and a power supply control method capable of extending the life of the storage battery.

  The storage battery conversion device according to the present invention is capable of performing a discharging operation for converting a DC voltage from the storage battery and supplying the converted voltage to the line, and a charging operation for converting the DC voltage from the line and supplying the same to the storage battery. A first control that includes a conversion unit and a control unit that controls a charging operation and a discharging operation of the voltage conversion unit, and the control unit avoids the charging operation when the storage amount of the storage battery increases and becomes equal to or greater than a storage amount upper limit value. The first control is stopped when the storage amount of the storage battery decreases to be less than or equal to the storage amount target value, and the second control for avoiding the discharge operation is performed when the storage amount of the storage battery decreases to be less than the storage amount lower limit value. The second control is stopped when the storage amount of the storage battery increases and becomes equal to or greater than the storage amount target value.

  In addition, the power supply system according to the present invention from another viewpoint converts the DC voltage from the power generator and supplies it to the line, and converts the AC voltage from the AC power source into a DC voltage. A converter for supplying AC power to the line, a discharge operation for converting the DC voltage from the storage battery and supplying the line, and a charging operation for converting the DC voltage from the line and supplying it to the storage battery. A storage battery conversion device capable of operating the storage battery, wherein the storage battery conversion device avoids the charging operation when a storage amount of the storage battery increases to a storage amount upper limit value or more. The control is started, the first control is stopped when the storage amount of the storage battery decreases to a storage amount target value or less, and the discharge operation is performed when the storage amount of the storage battery decreases to a storage amount lower limit value or less. Avoidance That the second control was started, the storage amount of the storage battery is stopped increase equal to or greater than the storage amount target value and the second control.

  In addition, the power supply control method according to the present invention from another viewpoint converts the DC voltage from the storage battery and supplies it to the line, and converts the DC voltage from the line and supplies it to the storage battery. A method for controlling power supply in a storage battery conversion device capable of performing a charging operation, the step of starting a first control for avoiding the charging operation when the storage amount of the storage battery increases and becomes equal to or greater than a storage amount upper limit value. And the step of stopping the first control when the storage amount of the storage battery decreases to be less than or equal to the target storage amount, and the discharge operation is avoided when the storage amount of the storage battery decreases to be less than the storage amount lower limit value. And starting the second control, and stopping the second control when the storage amount of the storage battery increases and becomes equal to or greater than the storage amount target value.

  The present invention can be realized not only as such a characteristic storage battery conversion device, power supply system, and power supply control method, but also by causing a computer to execute the characteristic steps performed in the power supply method. Or can be realized as a program. Moreover, it is realizable as a semiconductor integrated circuit which implement | achieves a part or all of the said converter for storage batteries, or an electric power supply system. Furthermore, the program can be stored in a recording medium such as a CD-ROM.

  ADVANTAGE OF THE INVENTION According to this invention, the lifetime of a storage battery can be extended by reducing the repetition frequency of charging / discharging of a storage battery.

It is a figure which shows the structure of the electric power supply system which concerns on this embodiment. It is a figure which shows the structure of the converter for storage batteries which concerns on this embodiment. It is a figure which shows an example of the correspondence of the charging rate and battery voltage of the storage battery which concern on this embodiment. It is a figure which shows the structure of the converter for power generators which concerns on this embodiment. It is a figure which shows an example of charging / discharging operation | movement of the converter for storage batteries which concerns on this embodiment. It is a figure which shows an example of charging / discharging operation | movement of the converter for storage batteries which concerns on this embodiment. It is a flowchart which shows the procedure of the electric power supply operation | movement by the converter for storage batteries which concerns on this embodiment. It is a flowchart which shows the procedure of the electric power supply operation | movement by the converter for storage batteries which concerns on this embodiment. It is a flowchart which shows the procedure of the electric power supply operation | movement by the converter for storage batteries which concerns on this embodiment. It is a flowchart which shows the procedure of the electric power supply operation | movement by the converter for storage batteries which concerns on this embodiment. It is a figure which shows an example of the electric power supply operation | movement by the storage battery converter concerning this embodiment.

[1. Summary of Embodiment]
In general homes and offices, power supplied to various electrical devices is usually AC power from the power system.

  On the other hand, for example, for the utilization of natural energy and coping with a power outage of the power system, a power generator such as a solar battery and a storage battery are installed, and the DC power from the power generator and the storage battery is changed to AC power. A DC power distribution system that has been converted into a power supply and supplied to various electrical devices has been developed. An example of this type of DC power distribution system is described in Patent Document 1.

  However, in the technique described in Patent Document 1, since the DC / DC converter maintains the line voltage in the DC bus line at a constant value, the charge / discharge repetition frequency of the storage battery increases. And if the repetition frequency of charging / discharging of a storage battery increases, there exists a possibility that the lifetime of a storage battery may be shortened by that much.

Embodiments of the present invention have been made in view of the above reasons, and the gist includes at least the configurations shown in (1) to (13) below.
(1) A conversion apparatus for a storage battery according to an embodiment of the present invention viewed from a certain viewpoint converts a DC voltage from a storage battery and supplies it to a line, and converts the DC voltage from the line into the storage battery. A voltage conversion unit capable of performing a charging operation to be supplied; and a control unit that controls a charging operation and a discharging operation of the voltage conversion unit, wherein the control unit stores a storage amount target value with respect to a storage amount of the storage battery, a storage amount The upper limit value and the storage amount lower limit value are held, and when the storage amount of the storage battery increases and exceeds the storage amount upper limit value, the first control for avoiding the charging operation is started, and the storage amount of the storage battery decreases and the storage amount target value The first control is stopped when the value falls below the value, and the second control for avoiding the discharge operation starts when the charge amount of the storage battery decreases and exceeds the lower limit value of the charge amount. If it falls below, the second control is stopped.

  According to this structure, the period when a control part performs 1st control, and the period when a control part performs 2nd control arise. And in the period when a control part performs 1st control or 2nd control, since charging operation or discharge operation is avoided, charging / discharging of a storage battery is not repeated. Thereby, since the repetition frequency of charging / discharging of a storage battery can be reduced, the lifetime improvement of a storage battery can be achieved.

(2) Moreover, in the storage battery conversion device according to the embodiment of the present invention, the storage amount target value held by the control unit may be variable.
According to this configuration, since the storage amount target value is variable, the difference between the storage amount target value and the storage amount upper limit value or the difference between the storage amount target value and the storage amount lower limit value can be set as appropriate. it can. Therefore, the length of the period during which the control unit performs the first control (the second control), that is, the period during which the storage battery is not repeatedly charged and discharged can be appropriately set.

(3) Moreover, the conversion apparatus for storage batteries which concerns on embodiment of this invention may be the structure where the said control part further changes at least one of the said electricity storage amount upper limit and the said electricity storage amount lower limit.
According to this configuration, it is possible to appropriately set the range in which the charged amount changes by changing the charged amount upper limit value or the charged amount lower limit value.

(4) Moreover, the storage battery converter according to the embodiment of the present invention has a configuration in which the control unit changes at least one of the storage amount upper limit value and the storage amount lower limit value based on the type of the storage battery. May be.
According to this configuration, the storage amount of the storage battery can be changed within an optimum range according to the type of the storage battery, so that deterioration of the storage battery can be suppressed.

(5) Moreover, the electric power supply system which concerns on embodiment of this invention seen from another viewpoint, the converter for power generators which converts the DC voltage from a generator and supplies it to a track | line, and the AC voltage from AC power supply Converter for AC power source that converts DC voltage to supply to the line, converter for load that converts DC voltage supplied from the line and supplies it to the load device, and DC voltage from the storage battery And a storage battery conversion device capable of performing a discharging operation for supplying to the line and a charging operation for converting a DC voltage from the line and supplying to the storage battery. When the storage amount of the storage battery increases and becomes equal to or higher than the storage amount upper limit value, the conversion device starts the first control to avoid the charging operation, and the storage amount of the storage battery decreases to be less than the storage amount target value. Become When the first control is stopped and the storage amount of the storage battery decreases and becomes less than or equal to the storage amount lower limit value, the second control for avoiding the discharge operation is started, and the storage amount of the storage battery increases and the storage amount When the target value is exceeded, the second control is stopped.
According to this structure, the period when the converter for storage batteries performs 1st control, and the period when a control part performs 2nd control arise. And in the period when the converter for storage batteries performs 1st control or 2nd control, since charging operation or discharge operation is avoided, charging / discharging of a storage battery is not repeated. Thereby, since the repetition frequency of charging / discharging of a storage battery can be reduced, the lifetime improvement of a storage battery can be achieved.

(6) The power supply system according to the embodiment of the present invention may be configured such that the storage battery conversion device changes the storage amount target value based on the generated power of the power generation device.
According to this configuration, it is possible to improve the utilization rate of the electric power generated by the power generation device and reduce the utilization rate of the electric power supplied from the AC power supply.

(7) Moreover, in the power supply system according to the embodiment of the present invention, the power generator is configured by at least one of one or more solar power generators and one or more wind power generators, and the storage battery conversion device. However, the power storage amount target value may be changed based on a change with time of the weather.
According to this configuration, the power supply system changes the target storage amount based on changes in the weather over time, so that it is possible to improve the use efficiency of the power generated by the power generation device composed of the solar power generation device. it can. Moreover, the utilization rate of a natural energy can be aimed at by shortening the period when the electric power supplied from the said AC power supply is used for charge of a storage battery.

(8) In addition, the power supply system according to the embodiment of the present invention further includes a weather prediction device that predicts a change with time of the weather, and the storage battery conversion device acquires information on the change with time of the weather from the weather prediction device. It may be configured to.
According to this configuration, the power supply system changes the target storage amount based on the change in the weather predicted by the weather prediction device, so the target storage amount is set to an optimum value for the weather at each time. can do. Therefore, it is possible to improve the use efficiency of the electric power generated by the power generation device configured from the solar power generation device.

(9) Moreover, the electric power supply system which concerns on embodiment of this invention WHEREIN: When the said converter for power generators and the said converter for alternating current power supplies the said converter for storage batteries is performing the said 1st control, the power generator The structure which performs output suppression control so that the sum of the electric energy supplied to the said track | line from the converter for AC and the converter for AC power supplies may become smaller than the power consumption of the said load apparatus may be sufficient.
When the storage battery conversion device performs the first control, the storage battery is not charged. Therefore, if the voltage of the line changes higher than the target voltage, the voltage of the line cannot be reduced by charging the storage battery, and the differential pressure between the voltage of the line and the target voltage may increase. .
On the other hand, according to the present configuration, when the storage battery conversion device performs the first control, the sum of the amounts of power supplied to the line from the power generation device conversion device and the AC power supply conversion device is Since the output suppression control is performed so as to be smaller than the power consumption of the load device, the differential pressure between the line voltage and the target voltage can be reduced.

(10) Further, in the power supply system according to the embodiment of the present invention, the power generation device conversion device and the AC power supply conversion device are configured to control output suppression in the priority order of the AC power supply conversion device and the power generation device conversion device. The structure which performs this may be sufficient.
According to this configuration, when the storage battery conversion device performs the first control, the AC power conversion device is supplied from the power generation device by performing output suppression in preference to the power generation device conversion device. The power usage rate increases. Therefore, the utilization rate of natural energy can be improved.

(11) Moreover, the electric power supply system which concerns on embodiment of this invention WHEREIN: When the said converter for power generators and the said converter for alternating current power supplies the said converter for storage batteries is performing said 2nd control, a power generator The output suppression cancellation (supply) control may be performed so that the sum of the amounts of power supplied to the line from the converter for AC and the converter for AC power supply becomes larger than the power consumption of the load device.
When the storage battery conversion device performs the second control, the storage battery is not discharged. Therefore, if the voltage of the line is lower than the target voltage, the voltage of the line cannot be increased due to the discharge of the storage battery, and the differential pressure between the voltage of the line and the target voltage may increase. .
On the other hand, according to this configuration, when the storage battery conversion device performs the second control, the sum of the amounts of power supplied to the line from the power generation device conversion device and the AC power supply conversion device is Since the output suppression control is canceled so as to be larger than the power consumption of the load device, the differential pressure between the line voltage and the target voltage can be reduced.

(12) Further, in the power supply system according to the embodiment of the present invention, the power generation device conversion device and the AC power supply conversion device are controlled so that the power generation device conversion device and the AC power supply conversion device are in priority order. The structure which cancels | releases may be sufficient.
According to this configuration, when the storage battery conversion device is performing the second control, the power generation device conversion device supplies power from the power generation device by releasing the output suppression in preference to the AC power supply conversion device. The utilization rate of generated power increases. Therefore, the utilization rate of natural energy can be improved.

(13) Moreover, the power supply control method according to the embodiment of the present invention viewed from another viewpoint converts the DC voltage from the storage battery and supplies it to the line, and converts the DC voltage from the line. A power supply control method in a storage battery conversion device capable of performing a charging operation to supply to the storage battery, wherein the charging operation is avoided when the storage amount of the storage battery increases and becomes equal to or higher than the storage amount upper limit value. 1 step of starting control, the step of stopping the first control when the storage amount of the storage battery decreases to a storage amount target value or less, and the storage amount of the storage battery decreases to a storage amount lower limit value or less. Then, starting the second control for avoiding the discharge operation, and stopping the second control when the storage amount of the storage battery increases and becomes equal to or more than the storage amount target value.
According to this structure, the period which performs 1st control, and the period when a control part performs 2nd control arise. And in the period which performs 1st control or 2nd control, since charging operation or discharge operation is avoided, charging / discharging of a storage battery is not repeated. Thereby, since the repetition frequency of charging / discharging of a storage battery can be reduced, the lifetime improvement of a storage battery can be achieved.

[2. Details of Embodiment]
<1> Configuration FIG. 1 is a diagram illustrating a configuration of a power supply system 201 according to the present embodiment.
The power supply system 201 includes a storage battery conversion device 101, a power generation device 102, a power generation device conversion device 103, an AC power supply 104, an AC power supply conversion device 105, a storage battery 106, and a load conversion device 107. Prepare.

  Here, the storage battery conversion device 101, the power generation device conversion device 103, the AC power supply conversion device 105, and the load conversion device 107 are electrically connected to the line 151.

  The power supply system 201 is a distributed power supply system such as a solar power supply system, for example, and supplies power to the load device 108 via the line 151. The power supply system 201 may perform grid interconnection, that is, the power supply destination from the line 151 may be on the AC power supply 104 side.

  In the power supply system 201, for example, DC power generated by the power generation device 102 is boosted by the power generation device conversion device 103 and charged in the storage battery 106, or converted into AC power by the load conversion device 107. It is supplied to the load device 108. Charge / discharge of the storage battery 106 is controlled by the storage battery conversion device 101.

  The power generation device 102 is a power generation device using natural energy, for example, a solar power generation device or a wind power generator, and outputs generated DC power to the power generation device conversion device 103. The output power of the power generator 102 is, for example, 2.4 kW.

  The power generator conversion device 103 is, for example, a DC / DC converter, and converts the DC power received from the power generator 102 into DC power having a different voltage value and outputs the DC power to the line 151. The power generation device conversion device 103 maximizes the output power of the power generation device 102 by performing MPPT (maximum power point tracking) control. In addition, the power generation device conversion device 103 can independently determine the state of power storage amount control described later in the storage battery conversion device 101 by monitoring the voltage of the line 151.

  The storage battery 106 is, for example, a lead battery, a lithium ion battery, a nickel-cadmium battery, a nickel-hydrogen battery, a redox flow battery, a NAS battery, an electric double layer capacitor, or a Li ion capacitor. The storage battery 106 has, for example, an electromotive force of 12 V, a capacity of 105 Ah, an output power of 5 kWh, and a 4-series lead storage battery. Alternatively, the storage battery 106 is, for example, a two-series Li-ion battery having an electromotive force of 30 V, a capacity of 40 Ah, and an output power of 2.4 kWh.

  The storage battery conversion device 101 is a bidirectional DC / DC converter, which converts DC power from the storage battery 106 into DC power having a different voltage value in a discharging operation and outputs the DC power to the line 151, and from the line 151 in a charging operation. The direct current power is converted into direct current power having a different voltage value and output to the storage battery 106.

  AC power supply conversion device 105 is an AC / DC converter including a power factor correction circuit and the like, converts 100V AC power received from AC power supply 104 in a commercial power system or the like into DC power, and outputs the DC power to line 151. For example, the AC power converter 105 performs constant current control for controlling the current supplied to the line 151 to a constant value. Further, the AC power conversion device 105 can independently determine the state of power storage amount control described later in the storage battery conversion device 101 by monitoring the voltage of the line 151.

  The load conversion device 107 is, for example, a DC / AC converter, and converts DC power from the line 151 into, for example, 100 V AC power and outputs the AC power to the load device 108. The load device 108 is, for example, a home appliance. The load conversion device 107 can be a DC / DC converter depending on the type of the load device 108.

  The combined capacity of the line 151 by the storage battery conversion device 101, the power generation device conversion device 103, the AC power supply conversion device 105, and the load conversion device 107 is 9 mF. The combined capacity and the power consumption of the load device 108 determine the slopes of the voltage rise and voltage drop of the line 151 when the storage battery 106 is charged and discharged.

FIG. 2 is a diagram showing a configuration of the storage battery conversion device according to the embodiment of the present invention.
The storage battery conversion device 101 includes a measurement unit 11, a control unit 12, a setting unit 14, a voltage conversion unit 13, voltage measuring devices 36 and 37, and a current measuring device 38.
The control unit 12 includes a computer. Each function of the control unit 12 is realized by a computer executing a predetermined computer program. Here, the computer includes a CPU (Central Processing Unit), a memory, an I / O interface, and a bus that connects these components to each other. Note that the control unit 11 is not necessarily limited to one configured from one computer, and may be configured from a plurality of computers. The control unit 12 includes a PI calculation unit 20, a charge / discharge determination unit 21, a battery remaining amount calculation unit 22, and a storage amount control unit 25.

The setting unit 14 sets various parameters that define the operation of the control unit 12. The setting unit 14 is configured using, for example, a known user interface.
The voltage conversion unit 13 includes a PWM (Pulse Width Modulation) circuit 23 and a step-up / down chopper circuit 24. The step-up / step-down chopper circuit 24 includes capacitors 31 and 35, a coil 32, and transistors 33 and 34.
The step-up / step-down chopper circuit 24 may be configured to include other types of switching elements instead of the transistors.

The voltage conversion unit 13 can perform a discharging operation that converts the DC voltage from the storage battery 106 and supplies the converted voltage to the line 151, and a charging operation that converts the DC voltage from the line 151 and supplies the same to the storage battery 106. The control unit 12 controls the charging operation and the discharging operation of the voltage conversion unit 13.

  Further, the voltage measuring device 37 measures the voltage Vdc of the line 151 and outputs the measured value to the measuring unit 11. The voltage measuring device 36 measures a battery voltage Vb that is, for example, a voltage between terminals of the storage battery 106, and outputs a measured value to the measuring unit 11. The current measuring device 38 measures a current flowing between the storage battery 106 and the voltage conversion unit 13, specifically, a battery current Ibdc input or output to the storage battery 106, and outputs a measured value to the measurement unit 11.

  Measurement unit 11 outputs measured values of voltage Vdc, battery voltage Vb, and battery current Ibdc to PI operation unit 20, and outputs measured values of voltage Vdc to charge / discharge determination unit 21. Measurement unit 11 measures the charging time and discharging time of storage battery 106, and outputs the charging time and discharging time, and measured values of battery voltage Vb and battery current Ibdc to battery remaining amount calculation unit 22.

  Based on the voltage Vdc input from the measurement unit 11, the charge / discharge determination unit 21 outputs either a charge operation start command for the storage battery 106 or a discharge operation start command for the storage battery 106 to the storage amount control unit 25. .

  The battery remaining amount calculation unit 22 calculates the storage amount (charge rate) of the storage battery 106 based on the measured values of the charging time and discharging time of the storage battery 106 and the battery voltage Vb and the battery current Ibdc received from the measurement unit 11. Then, the battery remaining amount calculation unit 22 outputs the calculated storage amount to the storage amount control unit 25.

FIG. 3 is a diagram illustrating an example of a correspondence relationship between the storage amount (charge rate) Q of the storage battery 106 and the battery voltage Vb according to the present embodiment.
The storage battery 106 is composed of, for example, a liquid lead storage battery for general starting or cycling. The storage battery 106 has a battery voltage, that is, an electromotive force of 12.72 V when the storage amount (charging rate) is 100%, and the electromotive force decreases as the storage amount decreases, and the electromotive force when the storage amount is 25%. It becomes 11.82V.

  For example, the storage battery conversion device 101 stores information indicating the correspondence relationship of FIG. Based on the measured values of the battery voltage Vb and the battery current Ibdc, the battery remaining voltage calculation unit 22 receives the electromotive force of the storage battery 106, that is, the terminal voltage of the storage battery 106, based on the charging and discharging times of the storage battery 106 received from the measurement unit 11. To calculate a voltage value excluding the voltage component due to the current flowing through the internal resistance of the storage battery 106. Then, the battery remaining amount calculation unit 22 calculates the amount of electricity stored in the storage battery 106 from the electromotive force of the storage battery 106 with reference to the information indicating the correspondence shown in FIG.

Returning to FIG. 2, the power storage amount control unit 25 determines whether or not to perform power storage amount control based on the power storage amount (charge rate) calculated by the battery remaining amount calculation unit 22. The storage amount control unit 25 holds a storage amount target value, a storage amount upper limit value, and a storage amount lower limit value. These values can be appropriately changed by the user using the setting unit 14.
The storage amount control unit 25 avoids the storage amount control (storage amount control OFF). In this case, the storage amount control unit 25 outputs the determination result of the charge / discharge determination unit 21 to the PI calculation unit 20 as it is. On the other hand, the power storage amount control unit 25 performs power storage amount control (power storage amount control ON). In this case, the storage amount control unit 25 forcibly converts one of the charging operation start command and the discharging operation start command input from the charge / discharge determination unit 21 into a charge / discharge stop command, Output to the PI calculation unit 20. In addition, the storage amount control unit 25 inputs information related to storage amount control to the power generation device conversion device 103 and the AC power supply conversion device 105.

  The PI calculation unit 20 performs a PI (proportional integration) calculation based on the command content input from the storage amount control unit 25 and the measured values of the voltage Vdc, the battery voltage Vb, and the battery current Ibdc input from the measurement unit 11. Then, the switching duty ratio of transistors 33 and 34 described later is calculated and output to the voltage conversion unit 13.

The voltage conversion unit 13 includes a PWM circuit 23 and a step-up / down chopper circuit 24.
The PWM circuit 23 generates PWM control signals for the transistors 33 and 34 in the step-up / step-down chopper circuit 24 according to the duty ratio input from the PI calculation unit 20, and outputs the PWM control signals to the transistors 33 and 34.

  The transistors 33 and 34 are, for example, IGBTs (Insulated Gate Bipolar Transistors) having a backflow prevention diode, and switch based on the PWM control signal received from the PWM circuit 23. Thereby, for example, in the discharging operation of the storage battery 106, the battery voltage Vb of the storage battery 106 is boosted and supplied to the line 151, and in the charging operation of the storage battery 106, the voltage Vdc of the line 151 is stepped down and supplied to the storage battery 106. .

For example, the voltage conversion unit 13 performs constant current charging as a charging operation of the storage battery 106 and performs constant current discharging as a discharging operation of the storage battery 106.
Here, in the charging operation of the storage battery 106, the control unit 12 always turns off the transistor 33 and switches the transistor 34 so that the input current Ibdc of the storage battery 106 becomes a predetermined value. In addition, in the discharging operation of the storage battery 106, the control unit 12 always turns off the transistor 34 and switches the transistor 33 so that the output current Ibdc of the storage battery 106 becomes a predetermined value.

The control unit 12 controls the current flowing from the voltage conversion unit 13 to the storage battery 106 in the charging operation to a constant value, and controls the current flowing from the storage battery 106 to the voltage conversion unit 13 in the discharging operation to a constant value.
This constant value is preset by the user, for example. Then, in the charging operation and discharging operation of the storage battery 106, the control unit 12 controls the transistors 33 and 34 so that the current Ibdc measured by the measurement unit 11 becomes a predetermined constant value.

FIG. 4 is a diagram showing a configuration of the power generator conversion device 103 according to the embodiment of the present invention.
The power generator conversion device 103 includes a measuring unit 41, a control unit 42, a voltage converting unit 43, voltage measuring devices 66 and 67, and a current measuring device 68. Voltage conversion unit 43 includes a PWM circuit 51 and a boost chopper circuit 52. Boost chopper circuit 52 includes capacitors 61 and 65, coil 62, transistor 63, and diode 64.

  Here, the voltage measuring device 67 measures the voltage Vdc of the line 151 and outputs the measured value to the measuring unit 41. The voltage measuring device 66 measures a power generation voltage Vg that is, for example, a voltage between terminals of the power generation apparatus 102, and outputs a measured value to the measurement unit 41. The current measuring device 68 measures the generated current Ig output from the power generation apparatus 102 and outputs the measured value to the measuring unit 41.

Measurement unit 41 outputs measured values of voltage Vdc, generated voltage Vg, and generated current Ig to control unit 42.
For example, the control unit 42 performs a PI (proportional integration) operation based on the measured values of the voltage Vdc, the generated voltage Vg, and the generated current Ig input from the measuring unit 41, and calculates the switching duty ratio of the transistor 63. Output to the voltage converter 43. Moreover, the control part 42 performs MPPT control based on the information regarding the storage amount control input from the storage battery conversion device 101.

The PWM circuit 51 generates a PWM control signal according to the duty ratio input from the control unit 42 and outputs it to the transistor 63 in the boost chopper circuit 52.
The transistor 63 is, for example, an IGBT, and switches based on a PWM control signal input from the PWM circuit 51. Thereby, for example, the power generation voltage Vg of the power generation apparatus 102 is boosted and supplied to the line 151.

<2> Operation <2-1> Basic Operation First, the basic operation of the storage battery conversion device 101 according to the present embodiment will be described.
Here, a case where the storage battery conversion device performs power storage amount control in the charge non-permission mode and a case where power storage amount control is performed in the charge non-permission mode will be described separately. Here, the “charge disapproval mode” means an operation method in which the storage battery 106 is discharged but charging is avoided. Further, the “discharge disapproval mode” means an operation method in which the storage battery 106 is charged but discharge is avoided.

<2-1-1> When the storage battery conversion device performs the storage amount control in the charge non-permission mode First, the case where the storage battery conversion device performs the storage amount control in the charge non-permission mode will be described.
FIG. 5 is a diagram illustrating an example of the charge / discharge operation of the storage battery conversion device 101 according to the present embodiment. Here, Qlo indicates the lower limit value of the storage amount Q of the storage value 106, and Qhi indicates the upper limit value of the storage amount Q.
First, it is assumed that the storage battery conversion device 101 is operating in a state where the storage amount control is stopped (OFF state).
When the voltage of the line 151 (hereinafter referred to as “line voltage”) Vdc is larger than the target voltage Vdc0, the storage battery conversion device 101 charges the storage battery 106, whereby the storage amount Q of the storage battery 106 increases. (Time T10 to Time T12).

During the period from time T10 to time T12, the sum of the power generated by the power generation apparatus 102 (hereinafter simply referred to as “generated power”) and the power supplied from the AC power source 104 (hereinafter referred to as “system power”). However, when it is larger than the power consumption of the load device 108, the line voltage Vdc increases (time T10 to time T11). Here, “generated power” corresponds to the power supplied to the line 151 from the power generator conversion device 102. Further, “system power” corresponds to power supplied from the AC power conversion device 105 to the line 151.
On the other hand, when the sum of the generated power and the system power is smaller than the power consumption of the load device 108, the line voltage Vdc decreases (time T11 to time T12). That is, the line voltage Vdc rises or falls according to the magnitude relationship between the sum of the generated power and the system power and the power consumption of the load device 108.
The principle of increase or decrease of the line voltage Vdc after time T12 is the same as the principle of increase or decrease of the line voltage Vdc from time T10 to time T12, and therefore the description thereof will be omitted as appropriate.

  After that, when the line voltage Vdc decreases and becomes smaller than the target voltage Vdc0, the storage battery conversion device 101 discharges the storage battery 106, whereby the storage amount Q of the storage battery 106 decreases (time T12 to time T14). ).

Thereafter, when the line voltage Vdc becomes higher than the target voltage Vdc0 due to the rise of the line voltage Vdc, the storage battery conversion device 101 charges the storage battery 106 again, and the storage amount Q of the storage battery 106 increases (time T14). -Time T15).
Then, when the storage amount Q of the storage battery 106 reaches the storage amount upper limit value Qhi, the storage battery conversion device 101 starts (ON) the storage amount control in the charge non-permission mode (time T15). Here, “reaching the storage amount upper limit value Qhi” does not mean strictly reaching the storage amount upper limit value Qhi, but reaching within a predetermined range near the storage amount upper limit value Qhi. Say.

  When the storage battery conversion device 101 performs power storage amount control in the charge disapproval mode, when the line voltage Vdc is higher than the target voltage Vdc0, the storage battery conversion device 101 stops both charging and discharging, and the storage battery 106 Is kept constant (time T15 to time T16). That is, the storage battery conversion device 101 avoids the charging operation when the line voltage Vdc is higher than the target voltage Vdc0.

  Thereafter, when the line voltage Vdc decreases and becomes smaller than the target voltage Vdc0, the storage battery conversion device 101 discharges the storage battery 106, and the storage amount Q of the storage battery 106 decreases (time T16 to time T18).

  After that, when the line voltage Vdc increases and becomes larger than the target voltage Vdc0, the storage battery conversion device 101 again stops both charging and discharging (avoids the charging operation), and the storage amount Q of the storage battery 106 becomes constant. It is maintained (time T18 to time T20).

Thereafter, when the line voltage Vdc decreases and becomes smaller than the target voltage Vdc0, the storage battery conversion device 101 discharges the storage battery 106 (time T20 to time T21). Here, the storage amount Q of the storage battery 106 decreases due to discharge.
Then, when the storage amount Q of the storage battery 106 reaches the storage amount target value Q0, the storage battery conversion device 101 stops (OFF) the storage amount control (time T21).

  Thereafter, when the line voltage Vdc rises and becomes larger than the voltage target value Vdc0, the storage battery converter 101 performs charging again (after time T22). Here, the storage amount Q of the storage battery 106 increases due to charging.

<2-1-2> Case where storage battery conversion device performs storage amount control in discharge non-permission mode Next, a case where storage battery conversion device 101 performs storage amount control in a charge non-permission mode will be described.
FIG. 6 is a diagram illustrating an example of the charge / discharge operation of the storage battery converter according to the present embodiment.
Here, the meanings of the symbols in FIG. 6 are the same as those in FIG.

First, it is assumed that the storage battery conversion device 101 is operating in a state where the storage amount control is stopped (OFF state).
When the line voltage Vdc is smaller than the target voltage Vdc0, the storage battery conversion device 101 discharges the storage battery 106, and the storage amount Q of the storage battery 106 decreases (time T50 to time T52).

  Here, the point that the line voltage Vdc rises or falls according to the magnitude relationship between the sum of the generated power and the system power and the power consumption of the load device 108 is that the line voltage at time T10 to time T12 described above. This is the same as the principle of increasing or decreasing the voltage Vdc. The principle of the rise or fall of the line voltage Vdc after the time T52 is the same as the principle of the rise or fall of the line voltage Vdc from the time T50 to the time T52 described above, and therefore the description thereof will be omitted as appropriate.

  Thereafter, when the line voltage Vdc rises and exceeds the target voltage Vdc0, the storage battery conversion device 101 charges the storage battery 106, and the charged amount Q of the storage battery 106 increases due to charging (time T52 to time T54). .

Thereafter, when the line voltage Vdc decreases and falls below the target voltage Vdc0, the storage battery conversion device 101 again discharges the storage battery 106, and the storage amount Q of the storage battery 106 decreases (time T54 to time T55). .
When storage amount Q of storage battery 106 reaches storage amount lower limit Qlo, storage battery conversion device 101 starts (ON) storage amount control in the discharge disapproval mode (time T55). Here, “reaching the storage amount lower limit value Qlo” does not mean strictly reaching the storage amount lower limit value Qlo, but reaching within a predetermined range near the storage amount lower limit value Qlo. Say.

  When the storage battery conversion device 101 performs the storage amount control in the discharge disapproval mode, when the line voltage Vdc is lower than the target voltage Vdc0, the storage battery conversion device 101 stops both charging and discharging, The amount of electricity stored in storage battery 106 is kept constant (time T55 to time T56). That is, the storage battery conversion device 101 avoids the discharging operation when the line voltage Vdc is smaller than the target voltage Vdc0.

  After that, when the line voltage Vdc rises and exceeds the target voltage Vdc0, the storage battery conversion device 101 charges the storage battery 106, and the storage amount Q of the storage battery 106 increases (time T56 to time T58).

  After that, when the line voltage Vdc decreases and falls below the target voltage Vdc0, the storage battery conversion device 101 again stops both charging and discharging (avoids the discharging operation), and the storage amount Q of the storage battery 106 is kept constant. (Time T58 to time T60).

Thereafter, when the line voltage Vdc increases and exceeds the target voltage Vdc0, the storage battery conversion device 101 charges the storage battery 106 (time T60 to time T61). Here, the storage amount Q of the storage battery 106 increases as a result of charging.
When storage amount Q of storage battery 106 reaches storage amount target value Q0, storage battery conversion device 101 stops (OFF) storage amount control (time T61).

  Thereafter, when the line voltage Vdc decreases and falls below the target voltage Vdc0, the storage battery conversion device 101 again discharges, and the storage amount Q of the storage battery 106 decreases (after time T63).

  In the above description, the voltage Vdc of the line 151 is not limited to a positive voltage, and may be a negative voltage. In the case of a negative voltage, an “increase” in voltage means that the magnitude of the voltage changes, for example, in the direction in which the absolute voltage value increases, and a “decrease” in voltage, for example, in the direction in which the absolute voltage value decreases It means that the size changes.

<2-2> Details of Operation of Storage Battery Conversion Device Next, details of the operation of the storage battery conversion device 101 will be described.
FIGS. 7-10 is a flowchart which shows the procedure of the electric power supply operation | movement by the storage battery converter 101 which concerns on this embodiment.

  As shown in FIG. 7, first, the storage battery conversion device 101 operates in a state in which the storage amount control is stopped (step S1).

  FIG. 8 is a flowchart showing the operation of the storage battery conversion device 101 in a state where the storage amount control is stopped. In FIG. 8, in the “stop mode”, the storage battery conversion device 101 stops the charging operation and the discharging operation of the storage battery 106. In the “charging mode”, the storage battery conversion device 101 performs the charging operation of the storage battery 106, and in the “discharge mode”, the storage battery conversion device 101 performs the discharging operation of the storage battery 106.

  As illustrated in FIG. 8, the storage battery conversion device 101 determines whether or not the line voltage Vdc is higher than the target voltage Vdc0 (step S11). Specifically, the charge / discharge determination unit 21 determines whether or not the line voltage Vdc is higher than the target voltage Vdc0.

  In step S11, when it is determined that the line voltage Vdc is larger than the target voltage Vdc0 (step S11: Yes), the storage battery conversion device 101 enters the charging mode (step S12). At this time, the control unit 12 always turns off the transistor 33 of the voltage conversion unit 13 and switches the transistor 34 so that the input current Ibdc of the storage battery 106 becomes a predetermined value.

  On the other hand, when it is determined in step S11 that the line voltage Vdc is equal to or lower than the target voltage Vdc0 (step S11: No), the storage battery converter 101 determines whether or not the line voltage Vdc is smaller than the target voltage Vdc0 ( Step S13).

  If it is determined in step S13 that the line voltage Vdc is smaller than the target voltage Vdc0 (step S13: Yes), the storage battery conversion device 101 enters the discharge mode (step S14). At this time, the control unit 12 always turns off the transistor 34 of the voltage conversion unit 13 and switches the transistor 33 so that the output current Ibdc of the storage battery 106 becomes a predetermined value.

  On the other hand, when it is determined in step S13 that the line voltage Vdc is equal to the target voltage Vdc0 (step S13: No), the storage battery conversion device 101 enters the stop mode (step S15). At this time, the control unit 12 stops the operations of both the transistors 33 and 34 of the voltage conversion unit 13.

Returning to FIG. 7, after step S <b> 1, the storage battery conversion device 101 determines whether or not the storage amount Q of the storage battery 106 exceeds the storage amount upper limit value Qhi (step S <b> 2).
If it is determined in step S2 that the charged amount Q has exceeded the charged amount upper limit value Qhi (step S2: Yes), the storage battery conversion device 101 performs charge amount control in the charge disapproval mode (charged amount control ON). (Step S3).

FIG. 9 is a flowchart showing the operation of the storage battery conversion device 101 when the storage amount control is performed in the charge disapproval mode. In FIG. 9, the operation of the storage battery conversion device 101 in the “stop mode”, “charge mode”, and “discharge mode” is the same as described above.
As shown in FIG. 9, the operation of the storage battery conversion device 101 in step S3 is substantially the same as the operation shown in FIG. 8, and when it is determined in step S11 that the line voltage Vdc is larger than the target voltage Vdc0 ( Step S11: Yes), the storage battery conversion device 101 is in the stop mode (step S22). The storage battery conversion device 101 avoids charging even when the line voltage Vdc is higher than the target voltage Vdc0 when performing the storage amount control in the charge non-permission mode.

Returning to FIG. 7, after step S <b> 3, the storage battery conversion device 101 determines whether or not the storage amount Q of the storage battery 106 falls below the storage amount target value Q <b> 0 (step S <b> 4).
In step S4, when it is determined that the storage amount Q does not fall below the storage amount target value Q0 (step S4: No), the storage battery conversion device 101 continues the storage amount control in the charge disapproval mode (step S3). . On the other hand, when it is determined in step S4 that the charged amount Q is less than the charged amount target value Q0 (step S4: Yes), the storage battery conversion device 101 stops the charged amount control (step S1).

  Further, when it is determined in step S2 that the charged amount Q does not exceed the charged amount upper limit value Qhi (step S2: No), the storage battery conversion device 101 determines that the charged amount Q of the storage battery 106 is less than the charged amount lower limit value Qlo. It is determined whether or not it has fallen below (step S5).

  In step S5, when it is determined that the storage amount Q is not lower than the storage amount lower limit Qlo (step S5: No), the storage battery conversion device 101 continues to stop the storage amount control (step S1). On the other hand, when it is determined in step S5 that the charged amount Q is lower than the charged amount lower limit Qlo (step S5: Yes), the storage battery conversion device 101 performs the charged amount control in the discharge non-permission mode (step S6). .

FIG. 10 is a flowchart illustrating the operation of the storage battery conversion device 101 when the storage amount control is performed in the discharge disapproval mode. In FIG. 10, the operation of the storage battery conversion device 101 in the “stop mode”, “charge mode”, and “discharge mode” is the same as described above.
As shown in FIG. 10, the operation of the storage battery conversion device 101 in step S6 is substantially the same as the operation shown in FIG. 8, and if it is determined in step S13 that the line voltage Vdc is smaller than the target voltage Vdc0 ( Step S13: Yes), the difference is that the storage battery converter 101 enters the stop mode (step S22). When the storage battery control device 101 performs the storage amount control in the discharge disapproval mode, the storage battery conversion device 101 avoids discharging even if the line voltage Vdc is lower than the target voltage Vdc0.

  Returning to FIG. 7, after step S <b> 6, the storage battery conversion device 101 determines whether or not the storage amount Q of the storage battery 106 exceeds the storage amount target value Q <b> 0 (step S <b> 7).

  In step S7, when it is determined that the storage amount Q does not exceed the storage amount target value Q0 (step S7: No), the storage battery conversion device 101 continues the storage amount control in the discharge non-permission mode (step S6). ). On the other hand, when it is determined in step S7 that the charged amount Q exceeds the charged amount target value Q0, the storage battery conversion device 101 stops the charged amount control (step S1).

<2-2> Setting Method of Storage Charge Target Value Next, a setting method of the storage charge target value in the storage battery conversion device 101 according to the present embodiment will be described.
The storage amount target value Q0 can be changed by the user using the setting unit 14. Thereby, the difference between the storage amount target value Q0 and the storage amount upper limit value Qhi, or the difference between the storage amount target value Q0 and the storage amount lower limit value Qlo can be set as appropriate. Therefore, the length of the period in which the control unit 12 performs the storage amount control in the charge non-permission mode (discharge non-permission mode), that is, the period in which the storage battery 106 is not repeatedly charged and discharged is appropriately set to a length desired by the user. be able to.

For example, it is assumed that the power generation apparatus 102 includes a solar power generation apparatus. In this case, it is preferable to change the storage amount target value according to the weather.
When the power generation device 102 is configured by a solar power generation device, the generated power of the power generation device 102 varies depending on the weather. For example, when “sunny”, the generated power increases, and when it is “rain”, the generated power decreases. Therefore, it is preferable to change the storage amount target value Q0 based on the generated power of the power generation apparatus 102.

  Specifically, when the generated power of the power generation apparatus 102 is large, the power storage amount target value Q0 may be set higher so that the period during which the storage battery 106 is charged becomes longer. On the other hand, when the generated power of the power generation apparatus 102 is small, the AC power supply 104 is dominant as a power supply source to the line 151. Therefore, the storage amount target value Q0 is set low so that the charging period of the storage battery 106 is shortened. do it. Thereby, the utilization factor of the electric power generated by the power generation apparatus 102 can be improved, and the utilization factor of the electric power supplied from the AC power source 104 can be reduced.

Table 1 below shows an example of the storage amount upper limit value Qhi, the storage amount target value Q0, and the storage amount lower limit value Qlo.

  As shown in Table 1, the storage amount target value Q0 is set to 75 [%] when the weather is clear, and is set to 25 [%] when the weather is rainy. Here, if the weather is “clear”, the generated power of the power generation apparatus 102 increases. Therefore, it is preferable to reduce the loss of generated power as much as possible by shortening the period during which the storage amount control is performed in the charge disapproval mode. Therefore, the target amount Q0 of electricity storage is set to a relatively high 75%, and the period during which the amount of electricity control is performed in the charge disapproval mode is shortened.

On the other hand, if the weather is “rain”, the power generated by the power generation device 102 decreases, and the power supplied from the AC power source 104 is dominant in the power supplied to the line 151.
Here, in order to improve the utilization rate of natural energy, it is advantageous that the period during which the power supplied from the AC power supply 104 is used for charging the storage battery 106 is short. Therefore, it is preferable to shorten the period during which the storage battery 106 is charged by the power supplied from the AC power supply 104 by shortening the period during which the storage amount control is performed in the discharge disapproval mode. Therefore, the storage amount target value Q0 is set to a relatively low value of 25% to shorten the period during which the storage amount control is performed in the charge disapproval mode.

As described above, in the power supply system 201 according to the present embodiment, the storage battery conversion device 101 changes the storage amount target value Q0 based on the change over time of the weather. The rate can be optimized.
Moreover, the utilization rate of natural energy can be improved by shortening the period when the electric power supplied from the AC power supply 104 is used for charging the storage battery 106.

<2-4> Output Suppression Control of Power Generation Device Conversion Device 103 and AC Power Supply Conversion Device 105 Next, output suppression control of power generation device conversion device 103 and AC power supply conversion device 105 will be described.
Here, the power generation device conversion device 103 and the AC power supply conversion device 105 allow the output suppression control so that one of the sum of the generated power and the system power and the power consumption of the load device 108 is greater than the other. I do.

FIG. 11 is a diagram illustrating an example of a power supply operation by the storage battery conversion device 101 according to the present embodiment.
It is assumed that the storage battery conversion device 101 stops the storage amount control (storage amount control OFF). Assume that the generated power of the power generation apparatus 102 is large and the sum of the generated power and the system power is larger than the power consumption of the load apparatus 108. In this case, the line voltage Vdc becomes higher than the target voltage Vdc0, and the storage battery conversion device 101 charges the storage battery 106. Then, the storage amount Q of the storage battery 106 increases.

  When the storage amount Q changes from the state where the storage amount Q is smaller than the storage amount upper limit value Qhi to the state where the storage amount Q is larger than the storage amount upper limit value Qhi due to the increase in the storage amount Q, the storage battery conversion device 101 does not charge. The storage amount control is started in the permission mode (storage amount control ON). At this time, the storage battery conversion device 101 repeats the stop mode and the discharge mode, and does not transition to the charge mode. Thereby, the storage amount Q of the storage battery 106 decreases.

After the storage amount control is started, the power generation device conversion device 103 and the AC power supply conversion device 105 perform output suppression control so that the sum of the generated power and the system power is smaller than the power consumption of the load device 108. .
Here, first, the AC power conversion device 105 stops the constant current control to suppress the output. In this state, the power generator conversion device 103 determines whether or not the line voltage Vdc is lower than the target voltage Vdc0. When it is determined that the line voltage Vdc is larger than the target voltage Vdc0, the power generating device conversion device 103 performs output suppression by stopping the MPPT control. That is, the power generation device conversion device 103 and the AC power supply conversion device 105 perform output suppression control in the priority order of the power generation device conversion device 103 and the AC power supply conversion device 105.

When the storage battery conversion device 101 performs power storage amount control in the charge disapproval mode, the storage battery 106 is not charged. Therefore, if the line voltage Vdc is higher than the target voltage Vdc0, the line voltage Vdc cannot be reduced by charging the storage battery 106, and the differential pressure between the line voltage Vdc and the target voltage Vdc0 increases. There is a fear.
On the other hand, as described above, the output suppression control is performed so that the sum of the generated power and the system power is smaller than the power consumption of the load device 108, so that the differential pressure between the line voltage Vdc and the target voltage Vdc0 is set. Can be reduced.

  In addition, when the storage battery conversion device 101 performs the storage amount control in the charge non-permission mode, the AC power conversion device 105 preferentially controls the output over the power generation device conversion device 103. Thereby, the utilization rate of natural energy can be improved.

  When the storage amount Q changes from the state where the storage amount Q is greater than the storage amount target value Q0 to the state where the storage amount Q is less than the storage amount target value Q0 due to the decrease in the storage amount Q, the storage battery conversion device 101 again controls the storage amount. Is stopped (power storage amount control OFF). At this time, the power generator converter 103 and the AC power converter 105 cancel the output suppression control.

  If the sum of the generated power and the system power is larger than the power consumption of the load device 108 after stopping the storage amount control, the storage battery conversion device 101 charges the storage battery 106. Then, the storage amount Q of the storage battery 106 increases again.

  When the storage amount Q changes from a state where the storage amount Q is smaller than the storage amount upper limit value Qhi to a state where the storage amount Q is greater than the storage amount upper limit value Qhi due to the increase in the storage amount Q, the storage battery conversion device 101 again does not permit charging. The storage amount control is started in the mode (storage amount control ON). Then, power generation device conversion device 103 and AC power supply conversion device 105 again perform output suppression control so that the sum of the generated power and the system power is smaller than the power consumption of load device 108.

Further, it is assumed that the storage battery conversion device 101 stops the storage amount control (storage amount control OFF) in a state where both the power generation device conversion device 103 and the AC power supply conversion device 105 are suppressing the output.
When the sum of the generated power and the system power is smaller than the power consumption of the load device 108, the storage battery conversion device 101 discharges the storage battery 106, and the storage amount Q of the storage battery 106 decreases.

  When the storage amount Q changes from a state where the storage amount Q is greater than the storage amount lower limit value Qlo to a state where the storage amount Q is less than the storage amount lower limit value Qlo due to a decrease in the storage amount Q, the storage battery conversion device 101 changes to the discharge non-permission mode. To start storage amount control (storage amount control ON). At this time, the storage battery conversion device 101 repeats the stop mode and the charge mode, and does not transition to the discharge mode. Thereby, the storage amount Q of the storage battery 106 increases.

After the storage amount control is started, the power generation device conversion device 103 and the AC power supply conversion device 105 cancel the output suppression control so that the sum of the generated power and the system power becomes smaller than the power consumption of the load device 108. I do.
Here, first, the power generation conversion device 103 starts the MPPT control to release the output suppression. In this state, AC power supply converter 105 determines whether or not line voltage Vdc is higher than target voltage Vdc0. When it is determined that the line voltage Vdc is smaller than the target voltage Vdc0, the AC power supply conversion device 103 releases the output suppression by starting constant current control. That is, the power generator converter 103 and the AC power converter 105 cancel the output suppression control in the priority order of the power converter 103 and the AC power converter 105.

When the storage battery conversion device 101 performs the storage amount control in the discharge non-permission mode, the storage battery 106 is not discharged. Therefore, if the line voltage Vdc is lower than the target voltage Vdc0, the line voltage Vdc cannot be increased due to the discharge of the storage battery 106, and the differential pressure between the line voltage Vdc and the target voltage Vdc0 increases. There is a fear.
On the other hand, in the converter for power generator 103 and the converter for AC power supply 105 according to the present embodiment, as described above, the sum of the generated power and the system power is larger than the power consumed by the load device. Cancel output suppression control. Therefore, the differential pressure between the line voltage Vdc and the target voltage Vdc0 can be reduced.

  In addition, when the storage battery conversion device 101 performs the storage amount control in the discharge non-permission mode, the power generation device conversion device 103 releases the output suppression in preference to the AC power supply conversion device 105. Thereby, the utilization rate of natural energy can be improved.

  When the storage amount Q changes from a state where the storage amount Q is smaller than the storage amount target value Q0 to a state where the storage amount Q is greater than the storage amount target value Q0 due to the increase in the storage amount Q, the storage battery conversion device 101 again controls the storage amount. Is stopped (power storage amount control OFF).

  After that, when the sum of the power generated by the power generation device 102 and the amount of power supplied from the AC power supply 104 is smaller than the power consumption of the load device 108, the storage battery conversion device 101 discharges the storage battery 106. Then, the amount of electricity stored in the storage battery 106 decreases again.

  When the storage amount Q changes from the state where the storage amount Q is greater than the storage amount lower limit value Qlo to the state where the storage amount Q is less than the storage amount upper limit value Qlo due to the decrease in the storage amount Q, the storage battery conversion device 101 again does not permit discharge. The storage amount control is started in the mode (storage amount control ON).

<3> Summary After all, according to the storage battery conversion device 101 according to the present embodiment, the control unit 12 performs the storage amount control (first control) in the charge non-permission mode, and the control unit 12 performs the discharge non-permission mode. Thus, a period for performing the storage amount control (second control) occurs. And in the period when the control part 12 performs charge amount control in charge non-permission mode or discharge non-permission mode, since charging operation or discharge operation is avoided, charging / discharging of the storage battery 106 is not repeated. Thereby, since the repetition frequency of charging / discharging of the storage battery 106 can be reduced, the lifetime of the storage battery 106 can be extended.

<Modification>
(1) In the embodiment, the example in which the storage amount target value is changed according to the weather has been described. However, the reference for changing the storage amount target value Q0 is not limited to the weather. May be.

表２に示すように、蓄電量目標値を、昼間の時間帯は７５％に設定し、夜間の時間帯は２５％に設定するようにしてもよい。 Table 2 below shows an example of the storage amount upper limit value Qhi, the storage amount target value Q0, and the storage amount lower limit value Qlo.

As shown in Table 2, the storage amount target value may be set to 75% during the daytime period and to 25% during the nighttime period.

  In this case, since the storage battery conversion device 101 changes the storage amount target value Q0 based on the time zone, it is possible to improve the use efficiency of the electric power generated by the power generation device 102 constituted by the solar power generation device. . Moreover, the utilization rate of a natural energy can be aimed at by shortening the period when the electric power supplied from the said AC power supply is used for charge of a storage battery.

(2) In the embodiment, the storage amount target value, the storage amount upper limit value, and the storage amount lower limit value may be changed according to the type of the storage battery 106.
The storage battery 106 has a different optimum range for changing the amount of stored electricity Q depending on its type. For example, when the storage battery 106 is composed of a lead battery, it is preferable that the storage amount Q changes in the vicinity of 100% (full charge). On the other hand, in the case where the storage battery 106 is composed of a lithium ion battery or the like, it is not preferable that the storage amount Q changes in the vicinity of 100%.

蓄電池１０６の種類が鉛蓄電池であれば、蓄電池１０６の蓄電量を１００％に近い状態で推移させるのが好ましい。そこで、蓄電池１０６の種類が鉛蓄電池の場合、蓄電量目標値を７５％とし、蓄電量上限値を１００％に設定している。 Table 3 below shows examples of the storage amount upper limit value Qhi, the storage amount target value Q0, and the storage amount lower limit value Qlo.

If the type of the storage battery 106 is a lead storage battery, it is preferable to change the amount of power stored in the storage battery 106 in a state close to 100%. Therefore, when the type of the storage battery 106 is a lead storage battery, the storage amount target value is set to 75%, and the storage amount upper limit value is set to 100%.

  On the other hand, if the type of the storage battery 106 is a lithium ion battery, a nickel cadmium battery, a nickel metal hydride battery, or a redox flow battery, it is preferable that the amount of power stored in the storage battery 106 be changed to 50% or less. Therefore, when the type of the storage battery 106 is a lithium ion battery or the like, the storage amount target value is set to 25%, and the storage amount upper limit value is set to 50%.

  According to this configuration, by changing the storage amount upper limit value Qhi or the storage amount lower limit value Qlo, it is possible to appropriately set the range in which the storage amount Q changes.

  Moreover, according to this structure, since the electrical storage amount of the storage battery 106 can be changed in the optimal range according to the kind of the storage battery 106, degradation of the storage battery 106 can be suppressed.

(3) The power supply system 201 according to the embodiment may further include a weather prediction device (not shown) that predicts a temporal change in weather. Then, the storage battery conversion device 101 may acquire information related to the temporal change of the weather from the weather prediction device.
According to this configuration, the storage battery conversion device 101 changes the storage amount target value based on the temporal change of the weather predicted by the weather prediction device, so that the storage device conversion device 101 is generated by the power generation device 102 configured of the solar power generation device. It is possible to improve the power usage efficiency.

(4) In the embodiment, an example in which the power generation device 102 is mainly configured by a solar power generation device has been described, but the power generation device 102 may be configured by a wind power generator. In this case, the storage amount target value Q may be changed based on the wind speed or the like at the place where the power generation apparatus 102 is installed.

  The above-described embodiments and modifications should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 11,41 Measuring part 12,42 Control part 13,43 Voltage conversion part 14 Setting part 20 PI calculating part 21 Charging / discharging determination part 22 Battery remaining charge calculation part 23,51 PWM circuit 24,52 Buck-boost chopper circuit 25 Power storage amount control Unit 31, 35, 61, 65 Capacitor 32, 62 Coil 33, 34, 63 Transistor 36, 37, 66, 67 Voltage measuring device 38, 68 Current measuring device 64 Diode 101 Conversion device for storage battery 102 Power generation device 103 Conversion for power generation device Device 104 AC power source 105 AC power source converter 106 Storage battery 107 Load converter 201 Power supply system

Claims (13)

A voltage converting unit capable of performing a discharging operation for converting a DC voltage from the storage battery and supplying the line to the line; and a charging operation for converting the DC voltage from the line and supplying the line to the storage battery;
A control unit for controlling the charging operation and the discharging operation of the voltage conversion unit,
The controller is
The storage amount target value, the storage amount upper limit value and the storage amount lower limit value with respect to the storage amount of the storage battery are retained,
When the storage amount of the storage battery increases and exceeds the storage amount upper limit value, the first control to avoid the charging operation is started, and when the storage amount of the storage battery decreases and falls below the storage amount target value, Stop the first control,
When the storage amount of the storage battery decreases and falls below the storage amount lower limit value, the second control for avoiding the discharge operation is started, and when the storage amount of the storage battery increases and exceeds the storage amount target value, The storage battery converter that stops the second control. The storage battery conversion device according to claim 1, wherein the storage amount target value held by the control unit is variable. The storage battery conversion device according to claim 1, wherein the control unit further changes at least one of the storage amount upper limit value and the storage amount lower limit value. The storage battery conversion device according to claim 3, wherein the control unit changes at least one of the storage amount upper limit value and the storage amount lower limit value based on a type of the storage battery. A converter for a power generator that converts the DC voltage from the power generator and supplies it to the line;
A converter for an AC power source that converts an AC voltage from an AC power source into a DC voltage and supplies the line to the line; and
A load conversion device for converting a DC voltage supplied from the line and supplying the load device to the load device;
A storage battery converter capable of performing a discharging operation for converting a DC voltage from a storage battery and supplying the line to the line; and a charging operation for converting a DC voltage from the line and supplying the battery to the storage battery. A feeding system,
The storage battery converter is
The first control for avoiding the charging operation is started when the storage amount of the storage battery increases to be equal to or higher than a storage amount upper limit value, and the first control is started when the storage amount of the storage battery decreases to be equal to or less than a storage amount target value. Stop
When the storage amount of the storage battery decreases and becomes less than or equal to the storage amount lower limit value, the second control for avoiding the discharging operation is started, and when the storage amount of the storage battery increases and becomes the storage amount target value or more, the second control is started. Power supply system that stops control. The power supply system according to claim 5, wherein the storage battery conversion device changes the storage amount target value based on the generated power of the power generation device. The power generator is composed of at least one of one or more solar power generators and one or more wind power generators,
The power supply system according to claim 6, wherein the storage battery conversion device changes the storage amount target value based on a temporal change in weather. It further includes a weather prediction device that predicts changes in the weather over time,
The power supply system according to claim 7, wherein the storage battery conversion device acquires information related to a temporal change in weather from the weather prediction device. When the storage battery converter performs the first control, the power generator converter and the AC power converter are supplied to the line from the power generator converter and the AC power converter. The power supply system according to any one of claims 5 to 8, wherein output suppression control is performed so that a sum of power amounts to be reduced is smaller than power consumption of the load device. The power supply system according to claim 9, wherein the power generation device conversion device and the AC power supply conversion device perform output suppression control in a priority order of the AC power supply conversion device and the power generation device conversion device. When the storage battery converter performs the second control, the power generator converter and the AC power converter are supplied to the line from the power generator converter and the AC power converter. The power supply system according to any one of claims 5 to 10, wherein output suppression release (supply) control is performed so that a sum of power amounts to be larger than power consumption of the load device. The power supply system according to claim 11, wherein the power generation device conversion device and the AC power supply conversion device cancel output suppression control in a priority order of the power generation device conversion device and the AC power supply conversion device. A power supply control method in a storage battery conversion device capable of performing a discharge operation for converting a DC voltage from a storage battery and supplying the line to a line, and a charging operation for converting a DC voltage from the line and supplying the line to the storage battery There,
Starting a first control for avoiding the charging operation when the storage amount of the storage battery increases and becomes equal to or greater than a storage amount upper limit;
Stopping the first control when the storage amount of the storage battery is reduced to be equal to or less than a storage amount target value;
Starting the second control for avoiding the discharge operation when the storage amount of the storage battery decreases and becomes less than or equal to a storage amount lower limit;
And a step of stopping the second control when the storage amount of the storage battery increases to be equal to or greater than the storage amount target value.

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