JP5451504B2 - Power distribution system - Google Patents

Description

  The present invention relates to a power distribution system that distributes DC power to load equipment based on power supplied from a plurality of power sources.

  Conventionally, as a power distribution system that distributes AC power and DC power in a building such as a house, a store, or an office building, there is one disclosed in Patent Document 1, for example. This power distribution system installs a DC power generation facility, such as a solar power generation device, in a building for in-house power generation, converts the DC power output of the DC power generation facility into AC power, and supplies the commercial power supply (AC It is a grid connection system that performs grid connection operation with a power system.

  In this type of grid-connected system, the DC power generated by the DC power generation facility is converted into AC power by a power converter (power conditioner) that converts DC power into AC power, thereby being a commercial AC power source. A configuration that cooperates with the power supply is adopted. Here, when the power exceeding the power consumed by the load in the building is supplied from the DC power generation facility, it is possible to reversely flow the surplus power to the commercial power supply (so-called power sale). .

  Further, as a power distribution system for supplying DC power to a DC load device, for example, a power supply system described in Patent Document 2 has been proposed. This power supply system performs communication between the DC power supply unit and the terminal device of the DC load device, and the power supply control means holds the received power supply information and the operation information storage means notified from the terminal device. Compared with power supply information, the output voltage is controlled so that the DC load device can receive the voltage and current required for driving.

JP 2003-284245 A JP 2009-159690 A

  As a configuration example of a power distribution system for distributing DC power, a power distribution system using a plurality of power sources such as a DC power generation facility such as a solar power generation device or a fuel cell power generation device, a commercial power source, or a storage battery is assumed. In this case, an output converter such as a DC-DC converter, an AC-DC converter or the like is provided for each power source, and a configuration in which DC power of a predetermined voltage level is output from each output converter is common. is there. In such a configuration, since the output voltage control of each output converter is performed individually, when the output converters are connected in parallel, it is not possible to know which output converter will output the output power. It may not be output from the converter. Even if the control voltage is set so that the output voltage is changed by the output converter, if the output voltage varies greatly due to variations in each control system, the magnitude relationship of the output voltages between the output converters is reversed. For example, the output voltage control of a plurality of output converters may not be performed properly. For this reason, there is a problem in that DC power is output from an output converter of another unintended power source.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide desired power in a system that distributes DC power using a plurality of power sources according to a predetermined order according to the state of each power source. An object of the present invention is to provide a power distribution system capable of outputting DC power from a power source output converter.

  The present invention provides a plurality of output converters that are provided corresponding to a plurality of power sources and that output DC power of a predetermined voltage level based on the power supplied from the connected power sources, and for a plurality of outputs. An output voltage control unit that controls an output voltage of the converter, and a system control unit that gives a command value to the output voltage control unit and instructs an output voltage control operation, wherein the output voltage control unit In accordance with the determined output priority order of the plurality of power sources, configure a feedback control system in which a high output voltage is set from the upper one so that the output voltage of each output converter has a predetermined voltage difference between each converter, The output voltage of each output converter is controlled with this set voltage as a target, and the system control unit provides one output voltage command value to the output voltage control unit to output a plurality of outputs. Providing power distribution system is intended to vary in conjunction with the output voltage of the converter.

  The present invention is the above power distribution system, wherein the output voltage control unit includes an output voltage detection unit that detects the output voltage of each of the plurality of output converters, and the output voltage detection unit includes each output converter. A configuration in which a predetermined voltage difference is provided for each detection voltage is included.

  In addition, the present invention includes the power distribution system described above, wherein the output voltage control unit includes a single integrated output voltage detection unit that detects output voltages of a plurality of output converters.

  The present invention is the power distribution system described above, wherein the output voltage detection unit includes a voltage dividing resistor, and a plurality of detection voltage differences set for each output converter by the voltage dividing resistor. Includes one that obtains the output voltage of the converter for output.

  Further, the present invention is the above power distribution system, wherein the output voltage control unit includes a reference voltage value based on an output voltage command value from the system control unit, and a detection voltage value of a plurality of output converters by the output voltage detection unit. Are included, and the comparison result is fed back to each output converter.

  Further, the present invention includes the power distribution system described above, wherein the output voltage control unit includes a voltage conversion unit that converts an output voltage command value from the system control unit into a reference voltage value.

  The present invention is the above power distribution system, further comprising an output state detection unit that detects the output state of each power source and each output converter, and the system control unit varies the output voltage command value according to the state. Including what to do.

  Further, the present invention is the above power distribution system, wherein the system control unit outputs an output voltage command value so that the output voltage of the output converter having the higher output priority order becomes a predetermined set output voltage. The output voltage command value is switched so that the output voltage of the output converter of the next rank becomes the set output voltage when the output from the output converter is not normally obtained.

  Moreover, this invention is said electric power distribution system, Comprising: As the converter for several outputs, the converter for solar cells connected to a solar cell, the converter for storage batteries connected to a storage battery, and AC connected to a commercial power source A DC converter, and the output voltage control unit sets an output voltage having a predetermined voltage difference in the order of solar battery> commercial power supply> storage battery as a set voltage of the plurality of output converters, Includes those that control the output voltage.

  The present invention is the above power distribution system, wherein the output unit of the storage battery converter includes a diode that separates the output voltage, and the output voltage control unit is an independent feedback that controls the output voltage of the storage battery converter. This includes a control system in which the set voltage of the independent feedback control system is set lower than the set voltage of other feedback control systems provided in the storage battery converter.

  Further, the present invention is the above power distribution system, wherein the independent feedback control system of the output voltage control unit detects the reference voltage value based on the output voltage command value from the system control unit and the output voltage of the storage battery converter. A comparison unit that compares the voltage value is included, and the comparison result is fed back to the storage battery converter.

  Moreover, this invention is said electric power distribution system, Comprising: The output part of the independent feedback control system provided in the converter for storage batteries includes what is connected with the converter for storage batteries via a feedback output switching part.

  Moreover, this invention is said power distribution system, Comprising: A system control part includes what monitors the input voltage and output voltage of a converter for storage batteries.

  Further, the present invention is the above-described power distribution system, wherein the output unit of the AC-DC converter includes a diode that separates the output voltage, and the output voltage control unit independently controls the output voltage of the AC-DC converter. Including a feedback control system that is set lower than the set voltage of another feedback control system provided in the AC-DC converter.

  Further, the present invention is the above-described power distribution system, wherein the independent feedback control system of the output voltage control unit is configured to calculate a reference voltage value based on an output voltage command value from the system control unit and an output voltage of the AC-DC converter. A comparison unit that compares the detected voltage value is included, and the comparison result is fed back to the AC-DC converter.

  Further, the present invention includes the power distribution system described above, wherein an output unit of an independent feedback control system provided in the AC-DC converter is connected to the AC-DC converter via a feedback output switching unit.

  Moreover, this invention is said power distribution system, Comprising: A system control part contains what monitors the input voltage and output voltage of an AC-DC converter.

  Further, the present invention is the above power distribution system, wherein the output unit of the solar cell converter is provided with a diode that separates the output voltage, and the system control unit outputs the input voltage and the output voltage of the solar cell converter. Includes monitoring.

  Moreover, this invention is said electric power distribution system, Comprising: As the converter for several outputs, the converter for solar cells connected to a solar cell, the converter for storage batteries connected to a storage battery, and AC connected to a commercial power source An output voltage control unit having a predetermined voltage difference in the order of solar battery> storage battery energy saving operation> commercial power supply> storage battery backup operation as set voltages of a plurality of output converters This includes setting the voltage and controlling the output voltage of each output converter.

  Further, the present invention is the above-described power distribution system, wherein the output voltage control unit is an independent feedback control system that controls the output voltage of the storage battery converter, and switching that turns on and off the operation of the independent feedback control system. And a switch that controls the output voltage during energy saving operation of the storage battery by an independent feedback control system.

  The present invention is the above power distribution system, wherein the output unit of the storage battery converter includes a diode that separates the output voltage, and the output voltage control unit is an independent feedback that controls the output voltage of the storage battery converter. The control system includes a first independent feedback control system on the cathode side of the diode and a changeover switch for turning on / off the operation of the first independent feedback control system, and a second independent feedback control system on the anode side of the diode. The output voltage at the time of the energy saving operation of the storage battery is controlled by the first independent feedback control system, and the set voltage of the second independent feedback control system is set from the set voltage of another feedback control system provided in the storage battery converter Including those set low.

  Moreover, this invention is said power distribution system, Comprising: The solar cell connected to a solar cell as an output converter provided with the output state detection part which detects the output state of each power source and each converter for output Converter, a storage battery converter connected to the storage battery, and an AC-DC converter connected to the commercial power source, and the system control unit is configured to store the storage battery in a power failure when power from the commercial power source is not supplied. When it becomes less than a predetermined value, the output from the converter for the storage battery is stopped, and the standby state for receiving the power supply from the storage battery by itself is included.

  Further, the present invention provides the power distribution system as described above, wherein the system control unit continues the standby state from the time of the power failure until the power is restored until at least the output range of the solar cell converter is within the output range. Including.

  Further, the present invention is the above-described power distribution system, wherein at least one of the plurality of output converters having the output priority set higher is configured by a converter having a drooping output characteristic. Including those that have been.

  According to the present invention, in a system that distributes DC power using a plurality of power sources, DC power is output from an output converter of a desired power source according to a preset order according to the state of each power source. It is possible to provide a power distribution system that can

The figure which shows the structure of the power distribution system which concerns on embodiment of this invention The figure which shows the principal part structure of the power distribution system of this embodiment The flowchart which shows the operation | movement procedure of the control part in the power distribution system of this embodiment. The figure which shows the example of the output voltage setting in the state of the power source in the power distribution system of this embodiment, and each state The figure which shows the 1st modification of the output voltage control part which made the output voltage detection part in this embodiment the other structure. The figure which shows the 2nd modification of the output voltage control part which made the output voltage detection part in this embodiment the other structure. The figure which shows the 3rd modification of the output voltage control part in this embodiment. The figure which shows the output characteristic of each electric power source in this embodiment The figure which shows the principal part structure of the power distribution system of 2nd Embodiment. The figure which shows the principal part structure of the power distribution system of 3rd Embodiment. The figure which shows the principal part structure of the power distribution system of 4th Embodiment. The figure which shows the principal part structure of the power distribution system of 5th Embodiment. The figure which shows the principal part structure of the power distribution system of 6th Embodiment. The figure which shows the principal part structure of the power distribution system of 7th Embodiment. The figure which shows the principal part structure of the power distribution system of 8th Embodiment. The figure which shows the principal part structure of the power distribution system of 9th Embodiment.

  Hereinafter, an embodiment in which a power distribution system according to the present invention is applied to a detached house will be described in detail with reference to the drawings. However, the building to which the power distribution system according to the present invention is applicable is not limited to a detached house, and can be applied to each dwelling unit or office of a collective housing.

  FIG. 1 is a diagram showing a configuration of a power distribution system according to an embodiment of the present invention. The power distribution system of the present embodiment is a configuration example applied to a hybrid power distribution system that includes a solar battery and a storage battery and that can distribute AC power and DC power. This distribution system constitutes an AC distribution board 104 that distributes AC power to an AC load device via an AC distribution path 106, and a DC distribution device that distributes DC power to a DC load device via a DC distribution path 107. DC distribution board 110 is provided. The AC distribution board 104 has an input terminal connected to a commercial power source (AC power system) 105 that is an AC power source and a power conditioner 103, and an output terminal connected to an AC distribution path 106 and a DC distribution board 110. ing. The AC distribution board 104 branches AC power supplied from the commercial power supply 105 or the power conditioner 103 and outputs the AC power to the AC distribution path 106 and the DC distribution board 110.

  As a DC power source of the power distribution system, a solar battery 101 and a storage battery 102 are provided. The solar cell 101 receives sunlight and photoelectrically converts it to generate electric power and output DC power, and constitutes a solar power generation device as an example of DC power generation equipment. The storage battery 102 includes a secondary battery capable of storing DC power and outputting the stored DC power. The DC distribution board 110 has a solar battery 101, a storage battery 102, and an AC distribution board 104 connected to an input end, and a DC distribution path 107 connected to an output end. The DC distribution board 110 includes a solar cell converter 111, a storage battery converter 112, and an AC-DC converter 113 as an output converter, and further includes a control unit 114 and a display unit 115.

  The output line of the solar cell 101 is branched into two, and the power conditioner 103 and the solar cell converter 111 of the DC distribution board 110 are connected in parallel. The power conditioner 103 converts the DC power output from the solar cell 101 into AC power synchronized with the phase of the commercial power source 105 and outputs the AC power, and reversely flows the converted AC power to the commercial power source 105. The solar cell converter 111 is configured to include a DC-DC converter, and converts DC power output from the solar cell 101 to a desired voltage level and outputs the voltage level. The storage battery converter 112 includes a DC-DC converter, converts the direct-current power output from the storage battery 102 to a desired voltage level, and outputs the voltage level. The AC-DC converter 113 converts the AC power supplied from the AC distribution board 104 into DC power having a desired voltage level and outputs it.

  The power conditioner 103 is a boost chopper circuit (not shown) that boosts the DC output of the solar battery 101, and converts the DC output boosted by the boost chopper circuit into a sinusoidal AC output synchronized with the phase of the AC power system AC. An inverter (not shown), an inverter control circuit (not shown) for adjusting the AC output by controlling the inverter, a system interconnection protection device, and the like.

  The AC distribution board 104 is a main breaker (not shown) whose primary side is connected to the commercial power source 105 in a box with a door, as well as a so-called residential distribution board (housing board), and two of the main breakers. A plurality of branch breakers and the like branched and connected to conductive bars (not shown) connected to the next side are accommodated. Further, the output line of the power conditioner 103 is drawn into the box of the AC distribution board 104, and the output line of the power conditioner 103 is connected in parallel to the commercial power source 105 in the box. In addition, an AC distribution path 106 is connected to the secondary side of the branch breaker, and AC power is supplied to an AC load device in the house via the AC distribution path 106.

  In the DC distribution board 110, each of the solar cell converter 111 and the storage battery converter 112 is configured by a switching regulator, for example, and detects the output voltage and outputs the output voltage so that the detected output voltage matches the target voltage. The voltage level of the DC power output from the solar cell 101 is converted to a desired voltage level by a constant voltage control method that performs increasing / decreasing control (feedback control). The AC-DC converter 113 is composed of, for example, a switching regulator, an inverter, and the like. The AC-DC converter 113 rectifies an AC voltage into a DC voltage and performs constant voltage control of the output voltage by feedback control, whereby the AC output from the AC distribution board 104 is performed. Convert power to DC power at the desired voltage level. The output terminals of the solar cell converter 111, the storage battery converter 112, and the AC-DC converter 113 are connected in parallel and connected to the DC distribution path 107, and a protection circuit (not shown) is provided in the DC distribution path 107. . Of the DC power converted to a desired voltage level by each of the output converters of the solar cell converter 111, the storage battery converter 112, and the AC-DC converter 113, any DC power is passed through the DC distribution path 107. Supplied to DC load equipment.

  The control unit 114 is configured by an information processing apparatus having a microcomputer or the like, and controls operation of each unit of the DC distribution board 110. The control unit 114 performs ON / OFF control of the operation of each converter of the solar cell converter 111, the storage battery converter 112, and the AC-DC converter 113, and output voltage control, and also performs display control of the display unit 115. The display unit 115 is configured by a liquid crystal display device or the like, and displays various information such as the operating state of the DC distribution board 110 by letters, numbers, images, and the like based on instructions from the control unit 114.

  In this embodiment, in the configuration in which DC power is distributed based on power supplied from a plurality of power sources such as the solar battery 101, the commercial power source 105, and the storage battery 102, the output voltage of the output converter connected to each power source is The control is performed so as to have a predetermined voltage difference between the converters. At this time, the output priority order of the plurality of power sources is determined in advance, and in accordance with this priority order, for example, higher output voltages are set in order from the higher order in the order of solar battery> commercial power> storage battery. Then, the output voltage control of each output converter is performed with the set voltage at which the output voltage is always a constant voltage difference among the converters of the solar cell converter 111, the AC-DC converter 113, and the storage battery converter 112 as a target voltage. . Thereby, according to the state of each electric power source, DC power can be output from the output converter of a desired electric power source according to a preset order. In this case, the output priorities of the plurality of power sources set in advance are solar cells in order of increasing set voltage> commercial power> storage batteries.

  At this time, when performing output voltage control of a plurality of output converters, one command value is given to the output voltage control unit, and feedback is made to the feedback control unit of each output converter according to the set voltage difference. To. As a result, even if the output voltage command value is varied and the output voltage is changed according to the state of each power source, the output voltage of all output converters maintains a relative voltage difference by feedback control. It will change in conjunction with it. For this reason, the output voltage of each output converter does not vary individually, and the voltage difference of the output voltage between the converters is always constant. Further, the output voltage detection units of the plurality of output converters are integrated, and the output voltage of each output converter is detected by one output voltage detection unit and applied to the feedback control unit. For example, a voltage dividing resistor having a predetermined voltage dividing ratio is provided in the output voltage detecting unit to connect the output terminals of the respective converters for output, and an output voltage having a detection voltage difference set for each output converter by the voltage dividing resistors is provided. These can be obtained, and these are used as the output voltage detection value (feedback detection voltage) of each output converter. As a result, the voltage difference between the output voltages of the output converters becomes constant, and even if the output state of any of the output converters changes, the output voltage of all the output converters becomes a relative voltage difference by feedback control. It is controlled while holding. For this reason, the output voltage of each output converter does not vary individually, and is controlled so as to have each set voltage having a certain voltage difference.

  In this way, by connecting the outputs of a plurality of output converters in parallel and performing output voltage control so that a constant voltage difference is always generated with respect to the output voltage of each output converter, the preset order of the output voltage is increased. Thus, DC power can be output from the output converter of any one of the power sources according to the state.

(First embodiment)
Next, a specific configuration example of the main part of the power distribution system according to the present embodiment will be described as the first embodiment. FIG. 2 is a diagram illustrating a main configuration of the power distribution system according to the present embodiment. The solar cell converter 111 connected to the output line of the solar cell 101 includes a feedback control unit 121 that performs feedback control of the output voltage, and a voltage detection unit 124 that detects the output voltage of the solar cell 101. The storage battery converter 112 connected to the output line of the storage battery 102 includes a feedback control unit 122 that performs feedback control of the output voltage, and a voltage detection unit 125 that detects the output voltage of the storage battery 102. The AC-DC converter 113 connected to the output line of the commercial power source 105 includes a feedback control unit 123 that performs feedback control of the output voltage, and a power failure detection unit 126 that detects a power failure state of the commercial power source 105. These output converters have their output ends connected in parallel to each other and connected to the DC distribution path 107.

  On the output side of the plurality of output converters, an output voltage control unit that feeds back a feedback control value to a feedback control unit 121, 122, 123 as a difference value between a reference voltage value based on an output voltage command value and an output voltage detection value 10 is provided. The DC distribution board 110 is provided with a system control unit 30 such as a microcomputer. The function of the control unit 114 of the DC distribution board 110 is realized by the output voltage control unit 10 and the system control unit 30. The output voltage control unit 10 is an output voltage command value from the system control unit 30, the solar cell output control unit 11, the storage battery output control unit 12, the AC-DC output control unit 13 that feeds back the feedback control value of each output converter. Is converted to a reference voltage value for each control unit.

  The output voltage control unit 10 constitutes one output voltage detection unit 15 integrated in the three control units of the solar cell output control unit 11, the storage battery output control unit 12, and the AC-DC output control unit 13. Each control unit includes a comparison unit 16 that compares the reference voltage value with the output voltage detection value. The output voltage detection unit 15 is constituted by a voltage dividing resistor in which resistance elements R1, R2, R3, and R4 are connected in series, and the voltage at the voltage dividing point of the connection part of each resistance element is the output voltage detection of each output converter. Output as a value. The comparison unit 16 includes comparators CP1, CP2, and CP3, compares the output voltage detection value of each output converter with the reference voltage value, and uses the difference value as a feedback control value as a feedback control unit 121, 122. , 123.

  Further, in the output voltage control unit 10, the storage battery output control unit 12 is provided with another output voltage detection unit 21 and a comparison unit 22 as an independent feedback control system. A diode 127 is connected in series between the output line of the storage battery converter 112 and a connection point with another output converter on the positive electrode side, and the diode 127 separates the output voltage from the storage battery 102 from other power sources. It has a configuration. A change-over switch 23 is provided at the output end of the comparison unit 22 so that the operation of an independent feedback control system by the output voltage detection unit 21 and the comparison unit 22 can be turned ON / OFF. The set voltage of the independent feedback control system is set lower than the set output voltages of the three cooperative feedback control systems by the solar cell output control unit 11, the storage battery output control unit 12, and the AC-DC output control unit 13. In addition, a changeover switch 128 is provided at the input portion of the storage battery converter 112 so that the output of the storage battery 102 can be turned ON / OFF.

  Further, the DC distribution path 107 is provided with an output voltage detection unit 25 that detects an output voltage of a DC power output output from one of the output converters. The output voltage detection unit 25, the voltage detection units 124 and 125, and the power failure detection unit 126 function as an output state detection unit. Converter output voltage information by the output voltage detection unit 25, solar cell output detection information by the voltage detection unit 124, storage battery output detection information by the voltage detection unit 125, and power failure detection information by the power failure detection unit 126 are input to the system control unit 30, The state of each part is determined. The system control unit 30 changes the output voltage command value and switches the output voltage of each output converter according to the state of each unit. Here, the system control unit 30 operates by receiving power supply from the output of the DC distribution path 107 or the storage battery 102. In these two power supply paths, diodes are connected in series, and cathodes of the diodes are connected in parallel and connected to the system control unit 30. With such diode connection, the DC power having the higher voltage is input to the system control unit 30.

  Next, the operation in the power distribution system of this embodiment will be described. FIG. 3 is a flowchart showing the operation procedure of the control unit in the power distribution system of the present embodiment. FIG. 3 shows a control procedure corresponding to the situation, focusing on the operation of the system control unit 30 that functions as the control unit 114 of the DC distribution board 110.

  The system control unit 30 refers to the output of the voltage detection unit 124 of the solar cell converter 111, and determines whether the output voltage of the solar cell 101 is within the output range of the solar cell converter 111 (step S11). Here, if it is within the output range of the solar cell converter 111, an operation command is transmitted to the solar cell converter 111 to turn on the operation of the solar cell converter 111 (step S12), and the output voltage control external A value V1 at the time of solar cell output is given to the output voltage controller 10 as a command value (output voltage command value) (step S13). Based on the external command value V1, a difference value between the output voltage detection value and the reference voltage value is fed back from the solar cell output control unit 11, the storage battery output control unit 12, and the AC-DC output control unit 13 of the output voltage control unit 10, respectively. The control values are fed back to the feedback control units 121, 122, and 123, and the output voltage control of each output converter is executed by the feedback control.

  Here, each set voltage is set in advance so that the output voltage of each output converter has a constant voltage difference in the order of solar cell> commercial power> storage battery, and is controlled with this set voltage as a target. . For this purpose, by configuring each resistance value that determines the voltage dividing ratio of the voltage dividing resistor in the output voltage detection unit 15 in advance, the output voltage detection value for each output converter is as follows: solar cell <commercial power source <storage battery. It has a certain voltage difference in order. Based on such an output voltage detection value, the output voltage control is performed by the feedback control unit of each output converter, whereby a desired output voltage having a certain voltage difference is output from each output converter.

  At the time of output from the solar battery 101, the output voltage of the solar battery converter 111 is controlled to be a predetermined set output voltage Vout by giving the external command value V1 as described above, and the direct current distribution path 107 is used. Is output (step S14).

  In step S <b> 11, if the output is out of the output range of the solar cell converter 111, the system control unit 30 refers to the output of the power failure detection unit 126 of the AC-DC converter 113 to determine whether the commercial power supply 105 is supplied. Is determined (step S15). Here, when the commercial power supply 105 is supplied and there is no power failure, an operation command is transmitted to the AC-DC converter 113 to turn on the operation of the AC-DC converter 113 (step S16), and output voltage control is performed. A value V2 at the time of commercial power output is given to the output voltage control unit 10 as an external command value (step S17). Based on the external command value V2, output voltage control of each output converter is executed by feedback control. At the time of output from the commercial power source 105, the output voltage of the AC-DC converter 113 is controlled so as to become a predetermined set output voltage Vout by giving the external command value V 2 as described above, via the DC distribution path 107. Is output (step S18).

  In step S15, when the commercial power supply 105 is not supplied and a power failure occurs, the system control unit 30 refers to the output of the voltage detection unit 125 of the storage battery converter 112 and is the output range of the storage battery 102. It is determined whether it is possible (step S19). Here, when it is within the output range of the storage battery 102, an operation command is transmitted to the storage battery converter 112 to turn on the operation of the storage battery converter 112 (step S20), and the storage battery output is output as an external command value for output voltage control. The hour value V3 is given to the output voltage control unit 10 (step S21). Based on the external command value V3, output voltage control of each output converter is performed by feedback control. At the time of output from the storage battery 102, the output voltage of the storage battery converter 112 is controlled to be a predetermined set output voltage Vout by giving the external command value V 3 as described above, and output via the DC distribution path 107. (Step S22).

  Here, since the output voltage of each output converter is set so as to maintain the magnitude relationship of solar cell> commercial power> storage battery, the value of the external command value has a magnitude relationship of V1 <V2 <V3. The output voltage from the output converter output at that time is controlled to the set output voltage Vout.

  In step S19, when the storage amount of the storage battery 102 is less than the predetermined value and is outside the output range, an operation command is transmitted to the storage battery converter 112 to turn off the operation of the storage battery converter 112 (step S23). The changeover switch 128 of the storage battery 102 is turned off (step S24), and the output from the storage battery converter 112 is stopped (step S25). Thereby, power is supplied only to the microcomputer of the system control unit 30.

  In the above operation example, the outputs of the voltage detection unit 124 of the solar cell converter 111, the power failure detection unit 126 of the AC-DC converter 113, and the voltage detection unit 125 of the storage battery converter 112 are determined, and each power source is determined. However, the state determination method is not limited to this. The state of each power source of the solar battery 101, the commercial power source 105, and the storage battery 102 is determined based on the output of the output voltage detection unit 25 of the DC distribution path 107, and the external command value for control is switched according to the state. It is also possible to perform output voltage control at the time of output from the source.

  FIG. 4 is a diagram illustrating an example of the state of the power source and the setting of the output voltage in each state in the power distribution system of the present embodiment. FIG. 4 assumes output power control from the solar cell 101 depending on the intensity of solar radiation in the daytime and night, and output power control for each state, assuming whether power supply from the commercial power source 105 is possible due to the presence or absence of a power failure. An example is shown. In the illustrated example, V01 to V07 are set to constant voltage differences, V04 is set to the set output voltage Vout, and the control target value (set voltage) of the output voltage of each output converter of the solar battery 101, the commercial power supply 105, and the storage battery 102 is set. Depending on the state, either (V04, V03, V02), (V05, V04, V03), or (V06, V05, V04) is set. Further, the external command value (output voltage command value) for setting the output voltage output from the system control unit 30 is V1 (solar battery) <V2 (commercial power supply) <V3 (storage battery).

  The solar cell 101 outputs generated power only in the daytime and stops outputting at night. The commercial power supply 105 normally outputs supply power, and stops output when a power failure occurs. The storage battery 102 is used for backup output, and charging power is output when there is no output from both the solar battery 101 and the commercial power source 105 (at the time of a power failure at night). If there is a long-term power outage at night, the battery is over-discharged. Therefore, when the capacity falls below the predetermined storage battery capacity, the output of the storage battery 102 is stopped and only the microcomputer of the system control unit 30 is used. A standby state for receiving power supply is set.

  Therefore, in the daytime, an external command value V1 is given from the system control unit 30 to set the set voltages of the output converters to (V04, V03, V02), and the set output voltage Vout from the solar cell converter 111 with the highest priority is set. Output. In this case, since the output voltage of the other output converter is lower than Vout, the DC power from the solar cell converter 111 is output. At night, an external command value V2 is given from the system control unit 30 to set the setting voltage of each output converter to (V05, V04, V03), and the setting output voltage Vout is output from the AC-DC converter 113 with the second priority. . In other words, the system control unit 30 switches the external command value from V1 to V2 during the transition from day to night, and shifts the output voltage while maintaining the voltage difference between the output converters. In this case, the solar cell converter 111 is in the operation OFF state, and the output voltage of the other output converters is lower than Vout, so that the DC power from the AC-DC converter 113 is output. At the time of transition from night to noon, the system control unit 30 switches the external command value from V2 to V1, shifts the output voltage while maintaining the voltage difference of each output converter, and is set by the solar cell converter 111. The output voltage Vout is output. Switching between daytime and nighttime control may be performed by monitoring the output of the solar cell 101 or the solar cell converter 111 and determining the state. The system control unit 30 may be provided with a timer such as a timer. It is also possible to determine and switch the state.

  In the event of a power failure at night, an external command value V3 is given from the system control unit 30 to set the set voltages of the output converters to (V06, V05, V04), and the set output voltage Vout from the storage battery converter 112 of priority 3 Output. That is, when a power failure occurs at night, the system control unit 30 switches the external command value from V2 to V3, and shifts the output voltage while maintaining the voltage difference between the output converters. In this case, the solar cell converter 111 and the AC-DC converter 113 are OFF, and DC power from the storage battery converter 112 is output. When recovering from the power failure, the system control unit 30 switches the external command value from V3 to V2, shifts the output voltage while maintaining the voltage difference of each output converter, and sets the set output voltage Vout from the AC-DC converter 113. Output.

  In addition, when a power failure occurs in the daytime, the system control unit 30 continues the output from the solar cell converter 111 while maintaining the external command value V1 without changing the operation. When a power failure occurs in the daytime and the night is not restored, the system control unit 30 switches the external command value from V1 to V3, and outputs DC power from the solar cell converter 111 to the storage battery converter 112. Switch. Further, when a power failure occurs at night and shifts to daytime without returning, the system control unit 30 switches the external command value from V3 to V1, and outputs the DC power from the storage battery converter 112 to the solar cell converter 111. Switch to. When the long-term power outage continues at night, the system control unit 30 stops the output of the storage battery converter 112 when the storage battery capacity of the storage battery 102 becomes equal to or less than a predetermined value, and sets the standby state. When returning from the standby state, the system control unit 30 sets the external command value to V1 when it is within the output range of the solar cell converter 111, and sets the external command value to V2 when it is out of the output range. If the output is possible, the output is made from the solar cell converter 111, and if not, the output is made from the AC-DC converter 113.

  As described above, the system control unit 30 outputs the external command value (output voltage command value) so that the output voltage of the output converter having the higher output priority is the predetermined set output voltage Vout, and the higher output When the output from the converter is not obtained normally, the output voltage command value is switched so that the output voltage of the next-order output converter becomes the set output voltage Vout. In this way, by performing output voltage control for each state, DC power is output from an output converter with higher priority among output converters that can output in each state in the order of solar cell> commercial power> storage battery. Can be made.

  In the power distribution system according to the present embodiment, the output voltage control unit 10 and the output voltage detection unit 15 are not limited to the configuration illustrated in FIG. 2, and may have other configurations. Hereinafter, modified examples of the configurations of the output voltage control unit and the output voltage detection unit will be described.

  FIG. 5 is a diagram showing a first modification of the output voltage control unit having another configuration of the output voltage detection unit in the present embodiment. The output voltage control unit 10A of the first modification includes an output voltage detection unit 15A in which the connection configuration of the voltage dividing resistor is changed. The output voltage detection unit 15A is configured by a voltage dividing resistor in which resistance elements R11, R12, and R13 are connected in parallel, these are connected in series to one resistance element R14, and each is divided by one resistor. . The voltage at the voltage dividing point of the connection portion between each of the resistance elements R11, R12, R13 and the resistance element R14 is output as an output voltage detection value of each output converter. In this case, the resistance value of each resistance element is set so that the output voltage detection value for each output converter has a certain voltage difference in the order of solar cell <commercial power source <storage battery. Others are the same as the structure of FIG.

  FIG. 6 is a diagram showing a second modification of the output voltage control unit having another configuration of the output voltage detection unit in the present embodiment. The output voltage control unit 10B of the second modification includes an output voltage detection unit 15B in which the connection configuration of the voltage dividing resistor is further changed. The output voltage detector 15B is configured by a voltage dividing resistor in which resistive elements R21 and R22, R23 and R24, and R25 and R26 are connected in series and divided in parallel. The voltage at the voltage dividing point at the connection portion of each of the resistance elements R21 and R22, R23 and R24, and R25 and R26 is output as an output voltage detection value of each output converter. In this case, the resistance value of each resistance element is set so that the output voltage detection value for each output converter has a certain voltage difference in the order of solar cell <commercial power source <storage battery. Others are the same as the structure of FIG.

  FIG. 7 is a diagram showing a third modification of the output voltage control unit in the present embodiment. The third modification includes output voltage control units 41, 42, and 43 for each output converter. The output voltage control unit 42 connected to the storage battery converter 112 includes a voltage conversion unit 44 and a storage battery output control unit 47. The storage battery output control unit 47 includes an output voltage detection unit 45 using a voltage dividing resistor and a comparison unit 46 using a comparator. It has. The configuration of the output voltage control units 41 and 43 is the same. These output voltage control units 41, 42, and 43 are given one output voltage command value from the system control unit 30, and perform feedback control of the output voltage of each output converter based on this output voltage command value. It has become. Others are the same as the structure of FIG.

  Also in these modified examples, by performing output voltage control of a plurality of output converters based on one command value, the output voltage of each output converter is controlled while maintaining a predetermined relative voltage difference, A predetermined output voltage can be obtained in a state where the voltage difference between the output voltages of the converters is always constant.

  As described above, in the present embodiment, output converters (solar cell converters 111) connected to each power source based on power supplied from a plurality of power sources (solar cell 101, storage battery 102, commercial power source 105). In the configuration in which DC power is output from the storage battery converter 112 and the AC-DC converter 113) and distributed, the output voltage is controlled so as to have a predetermined voltage difference between the output converters. Thereby, it is possible to output DC power from the output converter of a desired power source according to a preset order depending on the state of each power source. At this time, one command value is supplied to the output voltage control unit of each output converter so that the amount of change in the output voltage is substantially the same for each converter so that the output voltage of each output converter is relatively changed. Shall be given. As a result, variations in the output voltage command value, control target value, reference voltage value, etc. in the output voltage control section of each output converter can be reduced, and stable output from one output converter that is always set is possible. Become.

  Further, in the output voltage detectors 15, 15A, 15B that detect the output voltages of the plurality of output converters, a predetermined voltage difference is provided for each detected voltage. Thus, a detection voltage difference is provided for each converter for output, and three cooperative feedback control systems by the solar cell output control unit 11, the storage battery output control unit 12, and the AC-DC output control unit 13 are configured. Since this detected voltage difference is linked to the difference in control target value for each converter, the output voltage difference is set relatively in each converter for output, and it is possible to stably output from the converter with the highest output voltage setting. become. In addition, the output voltage detection units of the plurality of output converters are integrated to form a single output voltage detection unit 15. In this way, by providing a detection voltage difference for each converter in the same output voltage detection unit, variation in the detection value of the output voltage of each output converter, inversion of the output voltage, etc. are suppressed, and a predetermined value can be more stably determined. It is possible to output from the output converter. In addition, the output voltage detection unit is provided with a voltage dividing resistor, and a detection voltage difference between a plurality of output converters is obtained by the voltage dividing resistor. As a result, the detection voltage difference can be reliably set with a simple configuration.

  Further, the reference voltage value based on the output voltage command value from the external system control unit 30 (control unit 114) is compared with the detection voltage values of the output voltage detection units 15, 15A and 15B corresponding to the plurality of output converters. The comparison unit 16 is provided, and the comparison result is fed back to the feedback control units 121, 122, and 123, so that the output voltage can be variably set. As a result, the output voltage can be varied while maintaining a predetermined voltage difference. Further, in order to generate a reference voltage value of each output converter, a voltage conversion unit 14 that converts an output voltage command value from an external system control unit 30 into a reference voltage value is provided. Thereby, for example, the input variation (D / A error) of the output voltage command value can be reduced without providing a plurality of D / A converters for each output converter.

  In addition, each power source includes an output state detection unit that detects the output state of each output source, such as the output presence / absence of each output converter, and the system control unit 30 (control unit 114) outputs an output voltage command value according to the state. The output voltage of each output converter is changed while maintaining the voltage difference. As a result, when switching the output converter to be output according to the state, the system voltage (set output voltage) by the output voltage of the output converter (converter with the highest output voltage) is always constant, It is possible to output DC power.

  The output voltage set values of the output converters of the plurality of power sources are set as follows: solar cell converter 111> AC-DC converter 113> storage battery converter 112, solar cell 101> commercial power supply 105> storage battery 102. Sets the power source output priority. Thereby, the natural energy can be effectively used with the solar cell as the highest rank. In addition, by setting the storage battery to be used as a backup output at the time of a power outage at night as much as possible, it is used only when none of the upper power sources can be used, ensuring backup time when necessary. be able to.

  In addition, the output unit of the storage battery converter 112 is provided with a diode 127 to separate the output voltage by the diode 127, and an independent feedback control system (the output voltage detection unit 21 and the comparison unit 22) in the output voltage control unit 10. Another one is provided. Here, the set voltage of the independent feedback control system for the storage battery 102 is set lower than the set output voltages of the three cooperative feedback control systems. The storage battery 102 is normally set not to be used as a backup output as much as possible, and when it is output from another power source, the set voltage is lower than the other and is not output from the storage battery converter 112. I don't know if it is possible. For this reason, it is possible to check the output operation by separating the output voltage with a diode and outputting the output voltage at a voltage lower than the set output voltage with another feedback control system. In addition, since the storage battery 102 is in the output state, the converter output operation when using the storage battery can be speeded up, and the switching to the backup operation can be performed quickly.

  The independent feedback control system includes a comparison unit 22 that compares the reference voltage value based on the output voltage command value from the external system control unit 30 (control unit 114) and the detection voltage value of the output voltage detection unit 21. By providing the comparison result to the feedback control unit 122, the output voltage can be variably set. Thus, based on the output voltage command value, the output voltage can be relatively varied while maintaining a predetermined voltage difference from the voltage of the DC power from the power source that is currently outputting, and the converter output operation when using the storage battery can be performed. Can be fast.

  The setting of the output priority order of the plurality of power sources is not limited to the above order, and various setting examples are possible depending on the type and number of power sources, the specifications of the installation location, and the like. For example, using a storage battery as an energy-saving power source, the output voltage setting value of each output converter can be in the order of solar battery> storage battery (energy-saving operation)> commercial power> storage battery (backup operation). It is. Even when the output voltage is set as described above, it is possible to stably output from one output converter based on the output priority set in advance according to the state, similarly to the above-described control example. . In this setting example, the power is output from the storage battery before using the commercial power supply. Therefore, the power stored by the solar battery energy can be used from the storage battery, and energy saving can be achieved. In this case, the output voltage control of the storage battery during the energy saving operation uses an independent feedback control system by the output voltage detection unit 21 and the comparison unit 22, and the changeover switch 23 is provided so that the operation of the feedback control system can be switched. Thereby, if the preset battery remaining amount is reached, the output can be switched from the commercial power source to the storage battery, and the storage battery can be used for backup. When the independent feedback control system is switched by a changeover switch or the like as described above, a diode for separating the output voltage is not necessarily provided. In this configuration, the set voltage of the independent feedback control system can be arbitrarily set such that the set voltage of each of the three cooperative feedback control systems is set to any one of these intermediate voltages.

  Further, when backup is performed by outputting from the storage battery 102 at the time of power failure, output from the storage battery converter 112 is stopped when the storage amount of the storage battery 102 becomes smaller than a predetermined value. Until the upper power source recovers, only the microcomputer of the system control unit 30 is supplied with power from the storage battery 102 to enter a standby state. Thereby, the operation of the system control unit 30 can be continued, and the power from the upper power source can be immediately output when the power is restored. In addition, until the power is restored, at least until the solar cell 101 sufficiently generates power and falls within the output range of the solar cell converter 111, the standby state is continued and power is supplied only to the system control unit 30. To do. Thus, in the case of a long-term power outage, while the power supply from the solar battery 101 is stopped (nighttime), the backup output is stopped and only the microcomputer of the system control unit 30 is allowed to function, so that the next day When the battery 101 starts power generation, power can be restored immediately.

  As for the output converter of the power source with the output priority set higher, it is assumed that at least one output converter is composed of a converter having a drooping output characteristic. When a large current load is connected, output is possible from two or more power sources. FIG. 8 is a diagram showing the output characteristics of each power source in this embodiment, and is a characteristic diagram showing the output characteristics of each output converter of the solar cell converter 111, the AC-DC converter 113, and the storage battery converter 112. . In FIG. 8, in each output characteristic diagram, the horizontal axis represents current (A) and the vertical axis represents voltage (V), and each output converter has a drooping output characteristic. Combining the output characteristics of the three output converters results in the characteristic diagram on the lower side. At the rated output, DC power from the output converter of the highest voltage power source (here, the solar cell converter) is output. Is done. In the case of a load larger than the rated output (overcurrent load), it is possible to cope with a large capacity output by outputting from a plurality of power sources.

  According to the present embodiment, it is possible to output DC power from the output converter of a desired power source according to a preset order depending on the state of each power source. Also, by giving one output voltage command value, variations in the output voltage command value, control target value, reference voltage value, etc. for each output converter can be reduced, and stable from a predetermined output converter according to the setting. Can be output. In addition, since a predetermined voltage difference is provided for the detection voltage for each output converter, and the detection voltage difference is linked to the control target value difference for each output converter, the output voltage difference is relatively different in each output converter. It is possible to stably output from the converter having the highest output voltage setting. Further, by providing a detection voltage difference for each converter in the integrated output voltage detection unit, it is possible to suppress variations in the detected value of the output voltage of each output converter, inversion of the output voltage, etc. It is possible to output from the output converter. Further, by configuring the output voltage detection unit with a voltage dividing resistor, it is possible to reliably set the detection voltage difference with a simple configuration.

  Further, the output voltage control unit includes a comparison unit that compares a reference voltage value based on the output voltage command value from the system control unit and detection voltage values of the plurality of output converters by the output voltage detection unit. Are fed back to each output converter. Thereby, the output voltage of each output converter can be variably set, and the output voltage can be varied while maintaining a predetermined voltage difference. Further, by providing a voltage conversion unit that converts the output voltage command value from the system control unit into a reference voltage value, for example, without providing a plurality of D / A conversion units for each output converter, the output voltage command value Input variation (D / A error) can be reduced.

  In addition, an output state detection unit that detects the output state of each power source and each output converter is provided, and the system control unit varies the output voltage command value according to the state. As a result, the output voltage of each output converter is changed while maintaining the voltage difference, and the output converter (the converter with the highest output voltage) is output when switching the output converter to be output depending on the state. It is possible to output DC power so that the system voltage (set output voltage) by the output voltage is always constant. In addition, the system control unit outputs the output voltage command value so that the output voltage of the output converter with the higher output priority becomes the predetermined set output voltage, and the output from the higher output converter is normally obtained. If not, the output voltage command value is switched so that the output voltage of the next-order output converter becomes the set output voltage. Accordingly, it is possible to output DC power of a predetermined set output voltage from an output converter that can output in order from the higher one according to the output priority. Further, among the plurality of output converters, at least one or more output converters whose output priorities are set higher are configured by converters having drooping output characteristics. Thereby, when a large current load is connected, output from two or more plural power sources can be performed, so that a large capacity output can be handled.

  In the following embodiments, some variations of specific configuration examples of the power distribution system are shown. In the following, the same components as those in the first embodiment shown in FIG.

(Second Embodiment)
FIG. 9 is a diagram illustrating a main configuration of the power distribution system according to the second embodiment. As in the first embodiment, the power distribution system includes a solar cell converter 111, a storage battery converter 112, and an AC-DC converter 113. The output terminals of these converters are connected in parallel and connected to the DC distribution path 107, and DC power from any converter is output as a DC power output 131 via the DC distribution path 107.

  In the second embodiment, in the output voltage control unit 50A, the storage battery output control unit 12 is provided with another output voltage detection unit 21 and a comparison unit 22 as independent feedback control systems, and the storage battery converter 112 is provided. Connected to the output line. The comparison unit 22 includes a comparator CP4, and a changeover switch (SW) 23 is provided at the output terminal of the comparison unit 22 to turn on the independent feedback control system operation by the output voltage detection unit 21 and the comparison unit 22. Can be turned off. The changeover switch 23 is not only an ON / OFF switching type that turns on or off the output of the comparator CP4 of the comparison unit 22, but also selectively switches between the output of the comparator CP1 of the comparison unit 16 and the output of the comparator CP4 of the comparison unit 22. A two-system switching type switch or the like may be used. The output line of the storage battery converter 112 does not include a diode that separates the output voltage from other power sources.

  The comparison unit 22 compares the output voltage detection value of the storage battery converter 112 with the reference voltage value V4, and feeds back the difference value as a feedback control value to the feedback control unit of the storage battery converter 112. The system control unit 70A sets reference voltage values (set voltages) of the comparators of the comparison unit 16 and the comparison unit 22, performs detection of the remaining amount of the storage battery 102, and ON / OFF control of the changeover switch 23, thereby performing feedback control. Switches the system operation. Other configurations are the same as those of the first embodiment shown in FIG.

  At this time, the reference voltage value is V1> V4> V2> V3. For example, V1 = 48V, V4 = 47.5V, V2 = 47V, and V3 = 46V are set. The output voltage control (reference voltage value V4) by the independent feedback control system can be used for the operation of the storage battery in the energy saving mode. In the energy saving mode, the output power from the solar battery 101 is stored in the storage battery 102, and the power of the storage battery 102 is used, so that the power from the commercial power supply 105 is not used as much as possible to save labor. Thereby, the output voltage of each output converter is set to have a constant voltage difference in the order of solar battery> storage battery (for energy saving)> commercial power supply> storage battery (for backup).

  In the second embodiment, the output power of the storage battery 102 is output before using the output power from the commercial power supply 105 by switching the feedback control system according to the remaining amount of the storage battery 102. As a result, it is possible to use electric power stored by solar cell energy, and energy saving can be realized. Also, by setting the reference voltage value (set voltage) of the independent feedback control system arbitrarily for each reference voltage value (set voltage) of the three linked feedback control systems, the output priority of each output converter Can be changed.

(Third embodiment)
FIG. 10 is a diagram illustrating a configuration of main parts of the power distribution system according to the third embodiment. In the third embodiment, a diode 60 for separating an output voltage is provided in series between the output terminal of the storage battery converter 112 and the connection point of the output path on the positive electrode side of each output converter. Further, in the output voltage control unit 50B, the storage battery output control unit 12 is further provided with another output voltage detection unit 61 and a comparison unit 62 as an independent feedback control system, in the output line of the storage battery converter 112. It is connected to the anode side of the diode 60. The comparison unit 62 is configured to include a comparator CP5, compares the output voltage detection value on the near side of the diode 60 of the storage battery converter 112 with the reference voltage value V5, and uses the difference value as a feedback control value for the storage battery converter 112. Return to the feedback control unit. The system control unit 70B sets reference voltage values (set voltages) of the comparators of the comparison unit 16 and the comparison unit 62, and controls the operations of the three cooperative feedback control systems and the independent feedback control system. Other configurations are the same as those of the first embodiment shown in FIG.

  At this time, the reference voltage values are V1> V2> V3 and V3> V5. For example, V1 = 48V, V2 = 47V, V3 = 46V, and V5 = 45V are set. Thereby, the output voltage of each output converter is set to have a constant voltage difference in the order of solar battery> commercial power> storage battery (for backup)> storage battery (independent feedback). In this case, the output voltage is controlled at a voltage lower than the output voltage of the DC power output 131 from the storage battery converter 112 by an independent feedback control system on the front side of the diode 60 in the output line of the storage battery converter 112. become. By such output voltage control, the storage battery converter 112 is in a state of always outputting with the set voltage of the reference voltage value V5.

  In the third embodiment, when the output voltage of the storage battery converter 112 is separated and controlled by an independent feedback control system, the storage battery converter 112 always outputs and the output power from the storage battery 102 is used. The feedback response at the time of output switching can be improved. Thereby, the converter output switching operation when the storage battery is used can be speeded up.

(Fourth embodiment)
FIG. 11 is a diagram illustrating a configuration of main parts of the power distribution system according to the fourth embodiment. In the fourth embodiment, a storage battery converter input / output detection unit that detects the input and output of the storage battery converter 112 is provided, and the detection result of the storage battery converter input / output detection unit is input to the system control unit 70C. . The output voltage control unit 50C has the same configuration as the output voltage control unit 50B of the third embodiment illustrated in FIG. The system control unit 70C inputs the input voltage to the storage battery converter 112 or the detected value of the remaining amount of the storage battery 102 and the detected value of the output voltage from the storage battery converter 112, and inputs the input to the input unit of the storage battery converter 112. The voltage and the output voltage on the anode side of the diode 60 of the output unit are monitored.

  In the fourth embodiment, by monitoring the input voltage and output voltage of the storage battery converter 112, it is possible to determine a failure when the storage battery converter 112 is not output.

(Fifth embodiment)
FIG. 12 is a diagram illustrating a main configuration of a power distribution system according to the fifth embodiment. In the fifth embodiment, in the storage battery output control unit 12 of the output voltage control unit 50D, a diode 63 is connected in series to the output terminal of the comparator CP5 of the comparison unit 62 of the independent feedback control system. Further, a diode 64 is also provided in series with the output terminal of the comparator CP1 of the comparison unit 16 of the cooperative feedback control system, and the cathodes of these diodes 63 and 64 are connected in parallel to form a feedback output switching unit. It is connected to the feedback control unit of storage battery converter 112. Other configurations are the same as those of the fourth embodiment shown in FIG. The system control unit 70D has the same function as the system control unit 70C of the fourth embodiment.

  The diodes 63 and 64 of the feedback output switching unit can be provided by applying to any independent feedback control system of the configuration of the third embodiment in FIG. 10 or the configuration of the fourth embodiment in FIG. It is. Further, in place of the parallel connection of the diodes 63 and 64, an ON / OFF switching type switch or a two-system switching type switch is provided in the same manner as the change-over switch 23 of the second embodiment in FIG. It is also possible to switch the feedback output of 62 and 16.

  In the fifth embodiment, by providing a diode at the output of the comparator 62 of the independent feedback control system, output voltage control is performed by reliably switching the feedback operation between the cooperative feedback control system and the independent feedback control system. be able to. Further, by using a diode for switching the output of the feedback control system, the operation can be switched without requiring a control signal from the system control unit 70D, and a feedback output switching unit can be realized with a simple configuration.

(Sixth embodiment)
FIG. 13 is a diagram illustrating a configuration of main parts of a power distribution system according to the sixth embodiment. In the sixth embodiment, similar to the storage battery converter 112 of the third to fifth embodiments, the AC-DC converter 113 has an independent feedback control system. A diode 65 for separating the output voltage is connected in series between the output end of the AC-DC converter 113 and the connection point of the output path on the positive side of each output converter. In the output voltage control unit 50E, the AC-DC output control unit 13 is further provided with another output voltage detection unit 66 and a comparison unit 67 as an independent feedback control system. It is connected to the anode side of the diode 65 in the output line. The comparison unit 67 includes a comparator CP6, compares the output voltage detection value before the diode 65 of the AC-DC converter 113 with the reference voltage value V6, and uses the difference value as a feedback control value as an AC-DC converter. Return to the feedback control unit 113.

  In addition, a diode 68 is provided in series with the output terminal of the comparator CP6 of the comparator 67 of the independent feedback control system. In addition, a diode 69 is also provided in series with the output terminal of the comparator CP2 of the comparison unit 16 of the cooperative feedback control system, and the cathodes of these diodes 68 and 69 are connected in parallel to form a feedback output switching unit. It is connected to the feedback control unit of the AC-DC converter 113. The system control unit 70E sets reference voltage values (set voltages) of the comparators of the comparison unit 16, the comparison unit 62, and the comparison unit 67, and controls the operations of the three cooperative feedback control systems and the two independent feedback control systems. To do. Other configurations are the same as those of the fifth embodiment shown in FIG.

  At this time, the reference voltage values are V1> V2> V3, V3> V5, V2> V6, and V6> V5. For example, V1 = 48V, V2 = 47V, V3 = 46V, V6 = 46.5V, and V5 = 45V are set. As a result, the output voltage of each output converter is set to have a constant voltage difference in the order of solar battery> commercial power> commercial power (independent feedback)> storage battery (for backup)> storage battery (independent feedback). . In this case, similar to the storage battery converter 112 of the third to fifth embodiments, the AC-DC converter 113 is separated from the AC-DC converter 113 by an independent feedback control system on the front side of the diode 65 in the output line of the AC-DC converter 113. Therefore, the output voltage is controlled at a voltage lower than the output voltage at the DC power output 131. By such output voltage control, the AC-DC converter 113 is in a state of always outputting with the set voltage of the reference voltage value V6.

  In the sixth embodiment, the output voltage of the AC-DC converter 113 is separated and controlled by an independent feedback control system, so that the AC-DC converter 113 is always in the output state, and the output power from the commercial power source 105 is reduced. The feedback responsiveness at the time of output switching when using can be improved. Thereby, the converter output switching operation when using the commercial power supply can be speeded up.

(Seventh embodiment)
FIG. 14 is a diagram illustrating a configuration of main parts of a power distribution system according to the seventh embodiment. In the seventh embodiment, an AC-DC converter input / output detection unit that detects the input and output of the AC-DC converter 113 is provided, and the detection result of the AC-DC converter input / output detection unit is input to the system control unit 70F. It has a configuration. The output voltage control unit 50F has the same configuration as the output voltage control unit 50E of the sixth embodiment shown in FIG. The system control unit 70F inputs the detection value of the input voltage to the AC-DC converter 113 and the detection value of the output voltage from the AC-DC converter 113, the input voltage of the input unit of the AC-DC converter 113, The output voltage on the anode side of the diode 65 of the output unit is monitored. Similarly to the fourth to sixth embodiments, the input voltage of the input unit of the storage battery converter 112 and the output voltage on the anode side of the diode 60 of the output unit are monitored.

  In the seventh embodiment, by monitoring the input voltage and output voltage of the AC-DC converter 113, it is possible to determine a failure when the AC-DC converter 113 is not output.

(Eighth embodiment)
FIG. 15 is a diagram illustrating a configuration of main parts of a power distribution system according to the eighth embodiment. In the eighth embodiment, a solar cell converter input / output detection unit that detects the input and output of the solar cell converter 111 is provided, and the detection result of the solar cell converter input / output detection unit is input to the system control unit 70G. It has become. Between the output terminal of the solar cell converter 111 and the connection point of the output path on the positive electrode side of each output converter, a diode 80 for separating the output voltage is connected in series. The output voltage control unit 50G and other configurations are the same as those of the seventh embodiment shown in FIG. The system control unit 70G inputs the detection value of the input voltage to the solar cell converter 111 and the detection value of the output voltage from the solar cell converter 111, and the input voltage of the input unit of the solar cell converter 111; The output voltage on the anode side of the diode 80 of the output unit is monitored. Further, as in the seventh embodiment, the input voltage and the output voltage of the storage battery converter 112 and the AC-DC converter 113 are monitored.

  In the eighth embodiment, by monitoring the input voltage and the output voltage of the solar cell converter 111, it is possible to determine a failure when the solar cell converter 111 is not output.

(Ninth embodiment)
FIG. 16 is a diagram illustrating a configuration of main parts of a power distribution system according to the ninth embodiment. The ninth embodiment has a configuration in which the second embodiment shown in FIG. 9 and the eighth embodiment shown in FIG. 15 are combined. That is, in the output voltage control unit 50H, the storage battery output control unit 12 includes the output voltage detection unit 21, the comparison unit 22, the first independent feedback control system using the changeover switch 23, the output voltage detection unit 61, and the comparison unit 62. A second independent feedback control system is provided. The AC-DC output control unit 13 is provided with a third independent feedback control system including an output voltage detection unit 66 and a comparison unit 67. Diodes 60, 65 for separating the output voltage between the output terminals of the storage battery converter 112, the AC-DC converter 113, and the solar battery converter 111 and the connection point of the output path on the positive electrode side of each output converter. 80 are connected in series.

  At this time, the reference voltage values are V1> V4> V2> V3, V3> V5, V2> V6, and V6> V5. For example, V1 = 48V, V4 = 47.5V, V2 = 47V, V3 = 46V, V6 = 46.5V, and V5 = 45V are set. Thereby, the output voltage of each output converter has a constant voltage difference in the order of solar battery> storage battery (for energy saving)> commercial power supply> commercial power supply (independent feedback)> storage battery (for backup)> storage battery (independent feedback). Set to have.

  Similarly to the eighth embodiment, the system control unit 70H monitors the input voltage and the output voltage of the storage battery converter 112, the AC-DC converter 113, and the solar battery converter 111. Further, the system control unit 70H performs the remaining amount detection of the storage battery 102 and the ON / OFF control of the changeover switch 23 to switch the operation of the feedback control system, as in the second embodiment.

  In the ninth embodiment, an effect obtained by combining the second to eighth embodiments described above can be obtained. That is, by switching the feedback control system in accordance with the remaining amount of the storage battery 102, it is possible to use the power stored by the solar battery energy and realize energy saving. Moreover, the output priority of each converter for output can be changed by switching and operating an independent feedback control system. Further, by operating at least one of the control by the independent feedback control system of the storage battery converter 112 and the control by the independent feedback control system of the AC-DC converter 113, each converter output switching at the time of using the storage battery or the commercial power supply is performed. The operation can be made faster. Further, it is possible to determine the failure of each output converter of the storage battery converter 112, the AC-DC converter 113, and the solar battery converter 111.

  According to the present embodiment, the output voltage control unit sets an output voltage having a predetermined voltage difference in the order of solar battery> commercial power> storage battery as the set voltage of the plurality of output converters, By controlling the output voltage, it is possible to effectively use natural energy with the solar cell at the top. In addition, by setting the storage battery to be used as a backup output at the time of a power outage at night as much as possible, it is used only when none of the upper power sources can be used, ensuring backup time when necessary. It becomes possible.

  Also, the output operation of the storage battery is confirmed by separating the output voltage with a diode at the output of the storage battery converter and controlling the output at a voltage lower than the set voltage of the other feedback control system of the storage battery converter by an independent feedback control system. Is possible. In this case, since the storage battery converter stands by in the output state, it is possible to speed up the converter output switching operation when the storage battery is used, and to quickly switch the storage battery to the backup operation. In addition, the independent feedback control system, based on the output voltage command value from the system control unit, relatively outputs the output voltage while maintaining a predetermined voltage difference from the DC power voltage from the currently outputting power source. The converter output can be made faster when the storage battery is used.

  Further, the output voltage is separated by a diode at the output part of the AC-DC converter, and output control is performed with a voltage lower than the set voltage of the other feedback control system of the AC-DC converter by an independent feedback control system. The output operation can be confirmed. In this case, since the AC-DC converter stands by in the output state, the converter output switching operation when using the commercial power source can be speeded up, and the switching to the commercial power source can be speeded up. In addition, the independent feedback control system, based on the output voltage command value from the system control unit, relatively outputs the output voltage while maintaining a predetermined voltage difference from the DC power voltage from the currently outputting power source. It can be varied, and the converter output operation when using commercial power can be made faster.

  In addition, the output unit of the independent feedback control system is connected to each output converter via a feedback output switching unit such as a diode, so that a cooperative feedback control system of a plurality of output converters and an independent feedback control system can be used. Thus, it is possible to perform the output voltage control by switching the feedback operation with certainty. Further, when a diode is used, output switching of the feedback control system can be realized with a simple configuration. Further, in at least one of the storage battery converter, the AC-DC converter, and the solar battery converter, the failure of the output converter can be determined by monitoring the input voltage and the output voltage.

  Further, in the output voltage control unit, as a set voltage of the plurality of output converters, an output voltage having a predetermined voltage difference is set in the order of solar battery> storage battery energy saving operation> commercial power supply> storage battery backup operation, By controlling the output voltage of each output converter, it is possible to stably output from a predetermined output converter based on an output priority set in advance according to the state. In this case, since it outputs from a storage battery before using a commercial power supply, it becomes possible to use the electric power accumulate | stored with solar cell energy from a storage battery, and can attain energy saving. The output voltage control unit includes an independent feedback control system that controls the output voltage of the converter for the storage battery, and a changeover switch that turns on and off the operation of the independent feedback control system. The output voltage is controlled by an independent feedback control system. This allows the output to be switched from the commercial power source to the storage battery when, for example, the preset storage battery capacity is reached, and the storage battery can be used as a backup when none of the upper power sources can be used. It is. Moreover, the output priority of each converter for output can be changed by switching and operating an independent feedback control system.

  In addition, the system control unit stops the output from the storage battery converter and supplies power from the storage battery only by itself when the amount of power stored in the storage battery falls below a predetermined value during a power failure when power from the commercial power supply is not supplied. It is set as the structure made into the standby state which receives. As a result, it is possible to stop the backup output from the storage battery even in the event of a long-term power outage, to continue the operation of the system control unit, and to immediately output the power from the upper power source when the power is restored. In addition, the standby state is continued until at least the output range of the converter for solar cell is within the period from power failure to power recovery. As a result, in the case of a long-term power outage or the like, while the power supply from the solar battery is stopped (nighttime), the solar battery starts generating power by stopping the backup output from the storage battery and allowing the system control unit to function The power can be restored immediately.

  The present invention is intended to be variously modified and applied by those skilled in the art based on the description in the specification and well-known techniques without departing from the spirit and scope of the present invention. Included in the scope for protection. Moreover, you may combine each component in the said embodiment arbitrarily in the range which does not deviate from the meaning of invention.

10, 10A, 10B, 41, 42, 43, 50A, 50B, 50C, 50D, 50E, 50F, 50G, 50H Output voltage control unit 11 Solar cell output control unit 12, 47 Storage battery output control unit 13 AC-DC output control Unit 14, 44 voltage conversion unit 15, 15A, 15B, 21, 25, 45, 61, 66 output voltage detection unit 16, 22, 46, 62, 67 comparison unit 23 selector switch 30, 70A, 70B, 70C, 70D, 70E, 70F, 70G, 70H System control unit 60, 63, 64, 65, 68, 69, 80, 127 Diode 101 Solar cell 102 Storage battery 103 Power conditioner 104 AC distribution board 105 Commercial power supply 106 AC distribution path 107 DC distribution Route 110 DC distribution board (DC distribution device)
DESCRIPTION OF SYMBOLS 111 Solar cell converter 112 Storage battery converter 113 AC-DC converter 114 Control part 115 Display part 121,122,123 Feedback control part 124,125 Voltage detection part 126 Power failure detection part 128 Changeover switch 131 DC power output

Claims (24)

A plurality of output converters that are provided corresponding to a plurality of power sources, and that output DC power of a predetermined voltage level based on power supplied from the connected power sources;
An output voltage controller that controls output voltages of the plurality of output converters;
A power distribution system comprising: a system control unit that gives a command value to the output voltage control unit to instruct an output voltage control operation;
The output voltage control unit sets a high output voltage from the upper one so that the output voltage of each output converter has a predetermined voltage difference between each converter according to the output priority order of a plurality of power sources determined in advance. Configured to control the output voltage of each output converter with this set voltage as a target,
The system control unit is a power distribution system in which one output voltage command value is given to the output voltage control unit to change the output voltages of a plurality of output converters in conjunction with each other. The power distribution system according to claim 1,
The output voltage control unit includes an output voltage detection unit that detects an output voltage of each of the plurality of output converters, and the output voltage detection unit provides a predetermined voltage difference in the detection voltage for each output converter. Power distribution system. The power distribution system according to claim 2,
The output voltage control unit is a power distribution system including a single integrated output voltage detection unit that detects output voltages of a plurality of output converters. The power distribution system according to claim 3,
The output voltage detection unit is configured to include a voltage dividing resistor, and acquires output voltages of a plurality of output converters having a detection voltage difference set for each output converter by the voltage dividing resistor. Power distribution system. The power distribution system according to claim 2,
The output voltage control unit includes a comparison unit that compares a reference voltage value based on an output voltage command value from the system control unit and detection voltage values of a plurality of output converters by the output voltage detection unit. A power distribution system that feeds the results back to each output converter. The power distribution system according to claim 5,
The said output voltage control part is a power distribution system provided with the voltage conversion part which converts the output voltage command value from the said system control part into the said reference voltage value. The power distribution system according to claim 1,
The power distribution system includes an output state detection unit that detects an output state of each power source and each output converter, and the system control unit varies an output voltage command value according to the state. The power distribution system according to claim 7,
The system control unit outputs an output voltage command value so that the output voltage of the output converter having a higher output priority is a predetermined set output voltage, and the output from the higher output converter is normally obtained. A distribution system that switches the output voltage command value so that the output voltage of the next-order output converter becomes the set output voltage when there is no output voltage. The power distribution system according to claim 1,
As the plurality of output converters, a solar cell converter connected to a solar cell, a storage battery converter connected to a storage battery, and an AC-DC converter connected to a commercial power source,
The output voltage control unit sets an output voltage having a predetermined voltage difference in the order of solar battery> commercial power> storage battery as a set voltage of the plurality of output converters, and controls the output voltage of each output converter. Power distribution system. The power distribution system according to claim 9,
The output part of the storage battery converter comprises a diode for separating the output voltage,
The output voltage control unit includes an independent feedback control system that controls an output voltage of the storage battery converter, and a setting voltage of the independent feedback control system provided in the storage battery converter Distribution system set lower than. The power distribution system according to claim 10,
The independent feedback control system of the output voltage control unit includes a comparison unit that compares a reference voltage value based on an output voltage command value from the system control unit and a detection voltage value of the output voltage of the storage battery converter, A power distribution system that feeds back the comparison result to the storage battery converter. The power distribution system according to claim 10,
An output unit of an independent feedback control system provided in the storage battery converter is a power distribution system connected to the storage battery converter via a feedback output switching unit. The power distribution system according to claim 10,
The system control unit is a power distribution system that monitors an input voltage and an output voltage of the storage battery converter. The power distribution system according to claim 9,
The output part of the AC-DC converter includes a diode for separating the output voltage,
The output voltage control unit includes an independent feedback control system for controlling the output voltage of the AC-DC converter, and the setting voltage of the independent feedback control system is set in another feedback control system provided in the AC-DC converter. Power distribution system set lower than the set voltage. A power distribution system according to claim 14,
The independent feedback control system of the output voltage control unit includes a comparison unit that compares a reference voltage value based on an output voltage command value from the system control unit and a detected voltage value of the output voltage of the AC-DC converter. A power distribution system that feeds back the comparison result to the AC-DC converter. A power distribution system according to claim 14,
An output unit of an independent feedback control system provided in the AC-DC converter is connected to the AC-DC converter via a feedback output switching unit. A power distribution system according to claim 14,
The system control unit is a power distribution system that monitors an input voltage and an output voltage of the AC-DC converter. The power distribution system according to claim 13 or 17,
The output portion of the solar cell converter includes a diode for separating the output voltage,
The system control unit is a power distribution system that monitors an input voltage and an output voltage of the solar cell converter. The power distribution system according to claim 1,
As the plurality of output converters, a solar cell converter connected to a solar cell, a storage battery converter connected to a storage battery, and an AC-DC converter connected to a commercial power source,
The output voltage control unit sets an output voltage having a predetermined voltage difference in the order of solar cell> storage battery energy saving operation> commercial power supply> storage battery backup operation as a set voltage of the plurality of output converters, A power distribution system that controls the output voltage of each output converter. The power distribution system of claim 19,
The output voltage control unit includes an independent feedback control system that controls the output voltage of the storage battery converter, and a changeover switch that turns on and off the operation of the independent feedback control system. A power distribution system that controls the output voltage of the power supply by the independent feedback control system. The power distribution system of claim 19,
The output part of the storage battery converter comprises a diode for separating the output voltage,
The output voltage control unit turns on the first independent feedback control system and the operation of the first independent feedback control system on the cathode side of the diode as an independent feedback control system for controlling the output voltage of the storage battery converter. A second independent feedback control system on the anode side of the diode, and the output voltage during the energy saving operation of the storage battery is controlled by the first independent feedback control system. 2. A power distribution system in which a set voltage of the independent feedback control system is set lower than a set voltage of another feedback control system provided in the storage battery converter. The power distribution system according to claim 1,
An output state detector for detecting the output state of each power source and each output converter;
As the plurality of output converters, a solar cell converter connected to a solar cell, a storage battery converter connected to a storage battery, and an AC-DC converter connected to a commercial power source,
The system control unit stops the output from the storage battery converter when the power storage amount of the storage battery is less than a predetermined value at the time of a power failure in which power from the commercial power supply is not supplied, A power distribution system that is in a standby state to receive power supply. A power distribution system according to claim 22,
The said system control part is a power distribution system which continues the said standby state until it becomes in the output range of the said converter for solar cells at least from the time of the said power failure to power recovery. The power distribution system according to claim 1,
Of the plurality of output converters, at least one or more output converters having an output priority set higher are configured with a converter having a drooping output characteristic.

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