JPWO2013118376A1 - Power supply system and charge / discharge power conditioner used therefor - Google Patents

Abstract

Regardless of whether or not the power generator for power generation has a communication function, the power from the power generator is used without requiring manual operation at the time of a power failure in the commercial power system. The power supply system includes a solar cell power conditioner, a charge / discharge power conditioner, a first switch, and a detection unit. The solar cell power conditioner outputs power to the power supply path when a predetermined voltage is applied to the power supply path, and stops power output to the power supply path when a predetermined voltage is not applied to the power supply path. The first switch electrically disconnects the commercial power supply path when the commercial power system fails. The controller of the charging / discharging power conditioner is used for discharging from the charging / discharging power conditioner so that the voltage of the feeding path becomes a predetermined voltage when the commercial feeding path is electrically disconnected by the first switch. The effective value of the output voltage output toward the power supply path is changed.

Description

  The present invention relates to a power supply system that supplies power to a load and a charge / discharge power conditioner used therefor.

  Conventionally, a solar power generation system including a solar cell and a solar cell power conditioner has been known (see, for example, Japanese Patent Publication No. 9-135577).

  The solar cell power conditioner used in this solar power generation system performs an interconnected operation linked to the commercial power system, and can perform an independent operation independent from the commercial power system when the commercial power system fails. . Thereby, the solar cell power conditioner can supply electric power to the load even when the commercial power system fails.

  In order to perform the interconnection operation and the independent operation as described above, the solar cell power conditioner includes an interconnection output terminal for connecting a load to be supplied with power during the interconnection operation and a load to be supplied with power during the independent operation. And a self-supporting output terminal for connection.

  However, in the conventional solar battery power conditioner, the interconnection output terminal and the independent output terminal are separate terminals, and in order to switch from the interconnection operation mode to the autonomous operation mode when a power failure occurs in the commercial power system. A predetermined manual operation was required. That is, without the above-described manual operation, the conventional solar battery power conditioner cannot start independent operation independent from the commercial power system, and cannot effectively use the power generated by the solar battery. It was.

  In order to solve such a problem, it is conceivable to control the power output of the solar cell power conditioner by communication from the outside.

  However, when communicating with the solar cell power conditioner from the outside, only the solar cell power conditioner having a communication function can be supported.

  Accordingly, an object of the present invention is to use the power from the power generator without requiring manual operation at the time of a power failure in the commercial power system, regardless of whether or not the power generator for power generation has a communication function. An object is to provide a power supply system and a charge / discharge power conditioner used therefor.

  The power supply system of the present invention includes a power conditioner for power generation that controls power generation of a power generator, a power conditioner for charge / discharge that controls charge / discharge of a storage battery, and a commercial power supply path for supplying power from a commercial power system to a load. The power generation conditioner is connected to the load from the power generation conditioner and the charge / discharge power conditioner. The function of outputting power to the power supply path when a predetermined voltage is applied to the power supply path for power supply, and the power output to the power supply path is stopped when the predetermined voltage is not applied to the power supply path The switching unit electrically disconnects the commercial power supply path when the commercial power system fails, and the detection unit restores the commercial power system. When detected, the commercial power supply path is electrically connected, and the charge / discharge power conditioner controls an output control unit that controls power output to the power supply path, and a power failure that detects a power failure of the commercial power system. The power supply path when the power failure of the commercial power system is detected by the power failure detection unit and the commercial power supply path is electrically disconnected by the switching unit. The effective value of the output voltage output from the charging / discharging power conditioner toward the power feeding path is changed so that the voltage becomes the predetermined voltage.

  In this power supply system, the power generator for power generation has a function of suppressing power output to the power supply path when an effective value of the voltage of the power supply path is larger than a predetermined threshold value, The output control unit of the charge / discharge power conditioner is configured such that when a power failure of the commercial power system is detected by the power failure detection unit and the commercial power supply path is electrically disconnected by the switching unit, When charging satisfies a normal condition, the effective value of the output voltage is set to be equal to or less than the threshold value. When charging of the storage battery does not satisfy a normal condition, the effective value of the output voltage is set to be larger than the threshold value. It is preferable.

  In this power supply system, the charging / discharging power conditioner has a calculating unit that calculates charging power when charging the storage battery, and the output control unit is configured to receive the charging power calculated by the calculating unit. When the power exceeds the specified power, the effective value of the output voltage is increased at a predetermined first increase rate, the charging power is equal to or higher than the specified power, and the effective value of the output voltage is greater than the threshold value. When the large second threshold is exceeded, the effective value of the output voltage is increased at a second increase rate that is greater than or equal to zero and lower than the first increase rate, and the effective value of the output voltage is increased to the second threshold value. When the charging power is less than the specified power in a state larger than the threshold value, it is preferable to reduce the effective value of the output voltage.

  In this power supply system, the charge / discharge power conditioner includes a power change detection unit that detects a change direction of increase / decrease in the charge power, and the output control unit is in a state where the charge power is equal to or higher than the specified power. Thus, it is preferable that the effective value of the output voltage is maintained at the value at the time of detection when the charging power detection unit detects that the charging power is decreasing.

  In this power supply system, the charging / discharging power conditioner includes a calculating unit that calculates charging power when charging the storage battery, and the charging power calculated by the calculating unit is greater than or equal to a predetermined change rate. It is preferable to have a stop control unit that stops the power output from the power generator for power generation to the power conditioner for charging / discharging when it increases to a specified power or more.

  The power supply system includes a power generation switching unit inserted between the power generation power conditioner and the power feeding path, and the stop control unit of the charge / discharge power conditioner is configured such that the charging power is the change. It is preferable to control the power generation switching unit so as to electrically disconnect the power generation power conditioner and the power supply path when the power increases to a specified power or more after increasing at a rate.

  In this power supply system, the power conditioner for power generation has a function of stopping power output when an effective value of the voltage of the power supply path exceeds a predetermined abnormal stop value, and the power for charging and discharging The stop control unit of the conditioner is configured to increase the effective value of the output voltage to be larger than the abnormal stop value when the charge power increases at the change rate or more and becomes the specified power or more. Is preferably controlled.

  In this power supply system, it is preferable that the output control unit of the charge / discharge power conditioner changes an amplitude of the output voltage.

  In this power supply system, the output control unit of the charge / discharge power conditioner has a waveform equivalent to a waveform obtained by superimposing a wave having an instantaneous value of zero at a peak point of the sine wave on the sine wave. It is preferable to change the effective value of the output voltage by changing the waveform.

  In this power supply system, the output control unit of the charge / discharge power conditioner changes the waveform of the output voltage to a waveform equivalent to a waveform in which a second harmonic is superimposed on the fundamental wave as the sine wave. It is preferable to change the effective value of the output voltage.

  In this power supply system, the output control unit of the charge / discharge power conditioner changes the waveform of the output voltage to a waveform equivalent to a waveform obtained by amplifying a sine wave with a gain different depending on the phase of the sine wave. It is preferable to change the effective value of the output voltage.

  The charge / discharge power conditioner of the present invention is used in a power supply system.

  ADVANTAGE OF THE INVENTION According to this invention, the electric power from a generator can be utilized without requiring manual operation at the time of a power failure of a commercial power system | strain regardless of whether the power conditioner for electric power generation has a communication function.

Preferred embodiments of the invention are described in further detail. Other features and advantages of the present invention will be better understood with reference to the following detailed description and accompanying drawings.
1 is a schematic diagram illustrating a configuration of a power supply system according to a first embodiment. It is a circuit diagram which shows the structure of the principal part of the electric power supply system which concerns on Embodiment 1. FIG. It is explanatory drawing explaining operation | movement of the electric power supply system which concerns on Embodiment 1. FIG. It is explanatory drawing explaining operation | movement of the electric power supply system which concerns on Embodiment 1. FIG. It is explanatory drawing explaining operation | movement of the electric power supply system which concerns on Embodiment 1. FIG. It is explanatory drawing explaining operation | movement of the electric power supply system which concerns on Embodiment 1. FIG. 3 is a flowchart illustrating an operation of the power supply system according to the first embodiment. 3 is a flowchart illustrating an operation of the power supply system according to the first embodiment. FIG. 10 is an explanatory diagram for explaining the operation of the power supply system according to the second embodiment. 6 is a flowchart illustrating an operation of the power supply system according to the second embodiment. It is a circuit diagram which shows the structure of the principal part of the electric power supply system which concerns on Embodiment 3. It is explanatory drawing explaining operation | movement of the electric power supply system which concerns on Embodiment 3. FIG. 10 is a flowchart illustrating an operation of the power supply system according to the third embodiment. It is explanatory drawing explaining operation | movement of the electric power supply system which concerns on Embodiment 4. FIG. 10 is a flowchart illustrating an operation of the power supply system according to the fourth embodiment.

(Embodiment 1)
As shown in FIG. 1, the power supply system 1 according to the first embodiment includes a solar cell power conditioner (power conditioner for power generation) 2 that controls power generation of a solar cell (power generation device) 21, and a fuel cell (power generation device). And a fuel cell power conditioner (power conditioner for power generation) 3 for controlling power generation. The power supply system 1 also includes a charge / discharge power conditioner 4 that controls the charge / discharge of the storage battery 41. Furthermore, the power supply system 1 distributes the power to the load 8 and the switching panel 5 including the first switch (switching unit) 51 inserted in the commercial power supply path 91 for supplying power from the commercial power system 7 to the load 8. The distribution board 6 is provided. The solar cell power conditioner 2, the fuel cell power conditioner 3, and the charge / discharge power conditioner 4 are electrically connected to the distribution board 6 and the commercial power system 7 via the switching board 5.

  In this power supply system 1, the solar cell power conditioner 2, the fuel cell power conditioner 3, and the charge / discharge power conditioner 4 are temporarily stopped by the charge / discharge power conditioner 4 after a power failure of the commercial power system 7. In this system, the solar cell power conditioner 2 and the fuel cell power conditioner 3 are restarted.

  The load 8 is composed of, for example, a plurality (four in FIG. 1) of load devices 81, 81... Installed in a house. Each load device 81 is a home appliance such as a television, a microwave oven, a refrigerator, and a lighting fixture. Each load device 81 is directly connected to the distribution board 6 or connected to the distribution board 6 via an outlet (not shown).

  Although not shown, the distribution board 6 includes a main breaker and a plurality of branch breakers. The distribution board 6 distributes AC power to the load devices 81, 81,. The main breaker distributes AC power from the solar cell power conditioner 2, the fuel cell power conditioner 3, the charge / discharge power conditioner 4, and the commercial power system 7 to each branch breaker. The branch breaker supplies power from the main breaker to the load device 81 connected to itself.

  The solar cell 21 is installed, for example, on the roof of a dwelling unit and performs solar power generation. That is, the solar cell 21 generates direct-current power using solar energy. The “solar cell” of the present embodiment includes not only a single cell solar cell (solar cell) but also a solar cell module in which a plurality of solar cells are arranged in series or in parallel, or a plurality of solar cells. A solar cell array in which modules are arranged in series or in parallel is also included. A solar battery cell is a minimum unit configuration having a solar battery function. The solar cell module has a configuration in which a plurality of solar cells are arranged and covered with tempered glass and packaged. The solar cell array has a configuration in which a plurality of solar cell modules are arranged on a mount provided on a roof or the like.

  As shown in FIG. 2, the solar cell power conditioner 2 includes a power conversion unit 22, a control unit 23, and a pair of switches 24 and 24. The solar cell power conditioner 2 includes a voltage detection unit 251, a current detection unit 252, and a pair of output terminal units 26 and 26. This solar cell power conditioner 2 is an AC power (for example, 100V or 200V) adapted to the grid connection with the commercial power system 7 (see FIG. 1) for the DC power (for example, DC100V to 250V) generated by the solar cell 21. The AC power is output to the distribution board 6 (see FIG. 1). The solar cell power conditioner 2 controls the generated power of the solar cell 21.

  The power conversion unit 22 includes a DC / DC conversion unit 27 and a DC / AC conversion unit 28. The power conversion unit 22 operates according to instructions from the control unit 23.

  The DC / DC conversion unit 27 includes an inductor 271, a switching element 272, a diode 273, a capacitor 274, and a diode 275. The switching element 272 is an insulated gate bipolar transistor (IGBT, hereinafter referred to as “IGBT”), for example, and is switched on and off according to a control signal from the control unit 23.

  The DC / DC converter 27 converts the DC voltage input from the solar cell 21 into a DC voltage suitable for the DC / AC converter 28. Specifically, first, when the switching element 272 is turned on by the control signal from the control unit 23, the path of the direct current from the solar cell 21 becomes the path of the inductor 271 and the switching element 272. At this time, electromagnetic energy is stored in the inductor 271. Thereafter, when the switching element 272 is turned off by the control signal from the control unit 23, a back electromotive force is generated in the inductor 271, and the back electromotive force is added to the DC voltage from the solar cell 21. A larger DC voltage is output to the capacitor 274 side. The DC / DC converter 27 outputs the DC voltage smoothed by the capacitor 274 to the DC / AC converter 28.

  The DC / AC conversion unit 28 includes a switching circuit 281 and a filter circuit 282. In the DC / AC converter 28, the switching circuit 281 converts the DC voltage from the DC / DC converter 27 into an AC voltage, and the filter circuit 282 smoothes the AC voltage from the switching circuit 281.

  The switching circuit 281 includes four switching elements 291 to 294 and four diodes 295, 295,. The switching circuit 281 is a full bridge circuit composed of four switching elements 291 to 294. The switching elements 291 to 294 are, for example, IGBTs, and are switched on and off according to a control signal from the control unit 23. The switching circuit 281 converts the DC voltage from the DC / DC converter 27 into an AC voltage by switching on and off the switching elements 291 to 294. The AC voltage is output to the filter circuit 282.

  The filter circuit 282 includes an inductor 296, a capacitor 297, and an inductor 298.

  The control unit 23 includes a CPU (micro processor unit (MPU)) mounted on a computer as a main component, and operates according to a program, whereby the DC / DC conversion unit 27 and the DC / AC of the power conversion unit 22 are operated. The conversion unit 28 is controlled. At this time, the control unit 23 performs cooperative control with the commercial power system 7.

  The control unit 23 supplies power to the power supply path 92 when a predetermined voltage is applied to the power supply path 92 for supplying power from the solar cell power conditioner 2 and the charge / discharge power conditioner 4 to the load 8 (see FIG. 1). Has a power output function. The control unit 23 has a power failure detection function for detecting a power failure in the commercial power system 7 when a predetermined voltage is not applied to the power supply path 92. Furthermore, the control unit 23 has an isolated operation prevention function that stops power output to the power supply path 92 when a power failure of the commercial power system 7 is detected by the power failure detection function.

  The power failure detection function of the control unit 23 is a single operation detection function that detects that the solar battery power conditioner 2 is operating independently during a power failure of the commercial power system 7. As a detection method used for the isolated operation detection function, there are a passive method and an active method. Examples of the passive method include a voltage phase jump detection method, a third harmonic voltage distortion rapid increase detection method, and a frequency change rate detection method. Examples of the active method include a frequency shift method, a slip mode frequency shift method, an active power fluctuation method, a reactive power fluctuation method, and a load fluctuation method.

  In addition, the solar cell power conditioner 2 stores a program for the control unit 23 (computer) to execute various functions. The program is stored in advance in the solar cell power conditioner 2 when the solar cell power conditioner 2 is shipped. However, when the solar cell power conditioner 2 acquires the program after shipment, as an example of a method for the solar cell power conditioner 2 to acquire the program, a method using a computer-readable recording medium in which the program is recorded is used. There is. In the case of a method using a recording medium, the solar cell power conditioner 2 only needs to include a reading device (not shown) for reading data on the recording medium. Examples of the recording medium include an optical disk (CD-ROM, DVD-ROM) and a memory card. Examples of the reading device include a drive device that reads information on an optical disk, and a memory card reader that reads information on a memory card. Further, as another method for the solar battery power conditioner 2 to acquire the program, there is a method for downloading the program from another device (for example, a server) using a network. In the case of the method of downloading the above program, the solar battery power conditioner 2 only needs to have a communication function (not shown) for communicating with other devices using a network.

  Moreover, the solar cell power conditioner 2 is not limited to the circuit configuration shown in FIG. 2, and may have another known circuit configuration.

  A fuel cell power conditioner 3 shown in FIG. 1 controls power generation of a fuel cell (not shown), that is, power generated by the fuel cell. Further, the fuel cell power conditioner 3 converts the DC power generated by the fuel cell into AC power (for example, 100V or 200V) suitable for grid connection with the commercial power system 7, and converts this AC power to the distribution board. 6 is output. Similar to the solar cell power conditioner 2, the fuel cell power conditioner 3 has a power output function for outputting power to the power supply path 92 when a predetermined voltage is applied to the power supply path 92. The fuel cell power conditioner 3 has a power failure detection function for detecting a power failure in the commercial power system 7 when a predetermined voltage is not applied to the power supply path 92. Furthermore, the fuel cell power conditioner 3 has an isolated operation prevention function that stops power output to the power supply path 92 when a power failure of the commercial power system 7 is detected by the power failure detection function. Since the fuel cell power conditioner 3 has a well-known configuration, the description thereof is omitted. Further, the power failure detection function of the fuel cell power conditioner 3 is a single operation detection function that detects that the fuel cell power conditioner 3 is operating independently when the commercial power system 7 is out of power. The detection method used for the independent operation detection function of the fuel cell power conditioner 3 can adopt the same method as that of the solar cell power conditioner 2, but it is necessary to be the same method as that of the solar cell power conditioner 2. Absent.

  The switching board 5 includes a first switch (switching unit) 51 inserted in the commercial power supply path 91 and a detection unit 54 that detects power recovery of the commercial power system 7. In addition, the switching board 5 is provided between the second switch (power generation switching unit) 52 inserted between the solar cell power conditioner 2 and the power supply path 92, and between the fuel cell power conditioner 3 and the power supply path 92. And a third switch (power generation switching unit) 53 inserted into the.

  The detection unit 54 is provided on the commercial power supply path 91 between the commercial power system 7 and the first switch 51, and measures the voltage of the commercial power supply path 91 to restore the power of the commercial power system 7. To detect.

  The first switch 51 is turned off to electrically disconnect the commercial power supply path 91 when the commercial power system 7 fails. On the other hand, when the power recovery of the commercial power system 7 is detected by the detection unit 54, the first switch 51 is turned on to electrically connect the commercial power supply path 91. That is, the first switch 51 is in an on state during a normal time (non-power failure), and is in an off state during a power failure.

  The second switch 52 is provided by being inserted between the solar cell power conditioner 2 and the power supply path 92. When the commercial power system 7 fails, the second switch 52 is turned off to electrically disconnect between the solar cell power conditioner 2 and the power supply path 92. That is, the second switch 52 is in an on state during a normal time (non-power failure), and is in an off state during a power failure.

  The third switch 53 is inserted between the fuel cell power conditioner 3 and the power supply path 92. When the commercial power system 7 fails, the third switch 53 is turned off to electrically disconnect between the fuel cell power conditioner 3 and the power supply path 92. That is, the third switch 53 is in an on state during a normal time (non-power failure), and is in an off state during a power failure.

  The storage battery 41 is, for example, a nickel metal hydride battery, a lithium ion battery, a lead storage battery, or the like, and can store the generated power of the solar battery 21, the generated power of the fuel cell, and the commercial power of the commercial power system 7.

  As shown in FIG. 2, the charge / discharge power conditioner 4 includes a power conversion unit 42, a control unit 43, a pair of switches 44 and 44, and a pair of output terminal units 45 and 45. The charge / discharge power conditioner 4 includes a full charge detection unit 461, a current detection unit 462, and an output voltage detection unit 463. The charging / discharging power conditioner 4 converts an AC voltage from the distribution board 6 (see FIG. 1) into a DC voltage suitable for the storage battery 41 when the storage battery 41 is charged, and converts the DC voltage to the storage battery 41. Output to. On the other hand, when the storage battery 41 is discharged, the charge / discharge power conditioner 4 converts the DC voltage of the storage battery 41 into an AC voltage suitable for grid connection with the commercial power system 7 (see FIG. 1). The voltage is output to the distribution board 6.

  The power conversion unit 42 includes a DC / DC bidirectional conversion unit 47 and a DC / AC bidirectional conversion unit 48. The power conversion unit 42 operates according to an instruction from the control unit 43.

  The DC / DC bidirectional conversion unit 47 includes an inductor 471, two switching elements 472 and 473, two diodes 474 and 475, and a capacitor 476. The switching elements 472 and 473 are, for example, IGBTs, and are switched on / off according to a control signal from the control unit 43.

  The DC / AC bidirectional conversion unit 48 includes a switching circuit 481 and a filter circuit 482. The switching circuit 481 includes four switching elements 491 to 494 and four diodes 495, 495,. The filter circuit 482 includes an inductor 496, a capacitor 497, and an inductor 498. The switching elements 491 to 494 are, for example, IGBTs, and are switched on / off according to a control signal from the control unit 43.

  The DC / AC bidirectional conversion unit 48 converts the DC voltage from the DC / DC bidirectional conversion unit 47 into an AC voltage in the switching circuit 481 in accordance with an instruction from the control unit 43 during discharge, and in the filter circuit 482 The AC voltage from the switching circuit 481 is smoothed. On the other hand, at the time of charging, the DC / AC bidirectional conversion unit 48 converts the AC voltage from the power supply path 92 side into a DC voltage by the switching circuit 481 in accordance with an instruction from the control unit 43.

  The control unit 43 functions as a power failure detection unit, an output control unit, and a switching control unit, which will be described later, by using a CPU (microprocessor) mounted on the computer as a main component and operating according to a program. That is, the control unit 43 controls the DC / DC bidirectional conversion unit 47 and the DC / AC bidirectional conversion unit 48.

  The power failure detection unit detects a power failure in the commercial power system 7 when a predetermined voltage is not applied to the power supply path 92.

  The output control unit controls power output to the power supply path 92. The output control unit also has an independent operation detection function for detecting that the charge / discharge power conditioner 4 is operating independently during a power failure of the commercial power system 7. Thereby, an output control part stops the electric power output from the power conditioner 4 for charging / discharging to the electric power feeding path 92, when the power failure of the commercial power system 7 is detected by the power failure detection part. The detection method used for the independent operation detection function of the output control unit can adopt the same method as that of the solar cell power conditioner 2, but the same method as that of the solar cell power conditioner 2 and the fuel cell power conditioner 3. Need not be.

  When the power failure of the commercial power system 7 is detected by the power failure detection unit and the commercial power supply path 91 is electrically disconnected by the first switch 51, the output control unit temporarily stops power output, and then the power supply path 92. The effective value of the output voltage V1 on the power supply path 92 side is changed so that the voltage V2 applied to the power supply (hereinafter referred to as “power supply line voltage”) V2 becomes a predetermined voltage. That is, the output control unit performs current control at the time of charging / discharging of the storage battery 41 in a state linked to the commercial power system 7 (see FIG. 1), and a power failure of the commercial power system 7 is detected by the power failure detection unit. In this case, the effective value of the output voltage V1 is changed in accordance with at least one of the charge amount or charge / discharge power of the storage battery 41, and the operation is performed by voltage control.

  The output voltage V1 means not a voltage output from the charging / discharging power conditioner 4 toward the storage battery 41 for charging, but a voltage output toward the feeding path 92 for discharging.

  When the power failure detection unit detects a power failure in the commercial power system 7, the switching control unit outputs the off signal to the first switch 51 to control the first switch 51 to electrically connect the commercial power supply path 91. To cut. When the power recovery of the commercial power system 7 is detected by the detection unit 54, the switching control unit outputs the ON signal to the first switch 51 to control the first switch 51 to electrically connect the commercial power supply path 91. Connect.

  The charge / discharge power conditioner 4 stores programs for the control unit 43 (computer) to execute various functions. That is, the charge / discharge power conditioner 4 stores a program for causing the control unit 43 to function as an output control unit and a switching control unit. The program is stored in advance in the charge / discharge power conditioner 4 when the charge / discharge power conditioner 4 is shipped. However, when the charge / discharge power conditioner 4 acquires the program after shipment, an example of a method for the charge / discharge power conditioner 4 to acquire the program is a computer-readable recording medium on which the program is recorded. There is a technique to use. In the case of a method using a recording medium, the charge / discharge power conditioner 4 only needs to include a reading device (not shown) for reading data on the recording medium. Examples of the recording medium include an optical disk (CD-ROM, DVD-ROM) and a memory card. Examples of the reading device include a drive device that reads information on an optical disk, and a memory card reader that reads information on a memory card. Further, as another method for the charge / discharge power conditioner 4 to acquire the program, there is a method for downloading the program from another device (for example, a server) using a network. In the case of the method of downloading the above program, the charge / discharge power conditioner 4 only needs to have a communication function (not shown) for communicating with other devices using a network.

  When the sum of the output power of the solar cell power conditioner 2 and the output power of the fuel cell power conditioner 3 is smaller than the power consumption of the load 8, the charge / discharge power conditioner 4 is the difference between the power consumption and the sum. To discharge. On the other hand, when the sum is larger than the power consumption, the charge / discharge power conditioner 4 charges the difference between the sum and the power consumption.

  By the way, in the electric power supply system 1 of this embodiment, since the generated electric power P1 (refer FIG. 3) of the solar cell 21 changes with sunlight amounts, the output electric power of the solar cell power conditioner 2 changes. Further, when the power consumption of the load 8 is small, the charging power of the charging / discharging power conditioner 4 becomes large. For this reason, the output power of the solar battery power conditioner 2 is set to the specified power so that the storage battery 41 is not charged when the charge power of the charge / discharge power conditioner 4 is higher than the specified power (including the full charge state). Must be:

  Therefore, the power supply system 1 of the present embodiment can suppress the power output of the solar cell power conditioner 2 and the fuel cell power conditioner 3 on the charge / discharge power conditioner 4 side. Hereinafter, although the solar cell power conditioner 2 will be described, the same applies to the fuel cell power conditioner 3.

  In the power supply system 1 of this embodiment, the power output for the solar battery power conditioner 2 is controlled by the charge / discharge power conditioner 4 using the output suppression function of the solar battery power conditioner 2. With the output suppression function, the solar cell power conditioner 2 detects the effective value of the power supply path voltage V2, and when the effective value of the power supply path voltage V2 rises above the suppression start voltage V12 (see FIG. 3), the solar cell power conditioner This is a function to suppress the output power of the na 2. The suppression start voltage V12 is a predetermined value. That is, when the effective value of the power supply path voltage V <b> 2 exceeds the suppression start voltage V <b> 12, the solar cell power conditioner 2 performs suppression control that suppresses power generation of the solar cell 21. The solar cell power conditioner 2 is set with an overvoltage abnormal voltage V13 (see FIG. 3) that is higher than the suppression start voltage V12 and that stops the power output of the solar cell power conditioner 2.

  The control unit 43 of the charging / discharging power conditioner 4 has, as an output control unit, a power failure of the commercial power system 7 is detected by the power failure detection unit, and the commercial power supply path 91 is electrically disconnected by the first switch 51. In this case, when charging of the storage battery 41 satisfies a normal condition, the effective value of the output voltage V1 is set to be equal to or lower than the suppression start voltage V12. On the other hand, when the charging of the storage battery 41 does not satisfy normal conditions, the control unit 43 makes the effective value of the output voltage V1 larger than the suppression start voltage V12 in order to suppress the power output of the solar battery power conditioner 2. “When the charging of the storage battery 41 satisfies a normal condition” is when the charging amount of the storage battery 41 is less than the specified charging amount or when the charging power charged in the storage battery 41 is less than the specified power. On the other hand, “when the charge of the storage battery 41 does not satisfy normal conditions” means when the charge amount of the storage battery 41 is equal to or greater than the specified charge amount or when the charge power charged in the storage battery 41 is equal to or greater than the specified power. is there.

  In addition, the control unit 43 of the power conditioner 4 for charging / discharging functions as a calculation unit that calculates charging power when charging the storage battery 41. The calculation unit calculates the charging power when charging the storage battery 41 using the detection results of the current detection unit 462 and the output voltage detection unit 463.

  The output control unit performs voltage control so as to increase the effective value of the output voltage V1 at a predetermined first increase rate when the charging power calculated by the calculation unit becomes equal to or higher than the specified power. When the charging power is equal to or higher than the specified power and the effective value of the output voltage V1 exceeds the switching voltage (second threshold value) V14 that is greater than the suppression start voltage V12, the output control unit Voltage control is performed so as to increase the value at the second rate of increase. The second rate of increase is preset to a value that is greater than or equal to zero and lower than the first rate of increase. Further, when the charging power becomes less than the specified power in a state where the effective value of the output voltage V1 is larger than the switching voltage V14, the output control unit performs voltage control so as to decrease the effective value of the output voltage V1.

  A method of controlling the power output of the solar battery power conditioner 2 by the charge / discharge power conditioner 4 will be described with reference to FIG.

  When the output power of the solar cell power conditioner 2 (the generated power P1 of the solar cell 21) becomes equal to or higher than the preset load power P11 (time t1, t9 in FIG. 3), the charge / discharge power conditioner 4 In order to suppress the power output of the power conditioner 2, the effective value of the output voltage V1 of the charge / discharge power conditioner 4 is increased at a first rate of increase.

  As the effective value of the output voltage V1 increases, it reaches the suppression start voltage V12 (time t2, t10). When the effective value of the output voltage V1 reaches the suppression start voltage V12, the solar cell power conditioner 2 starts suppressing power output with a certain delay time (suppression start delay T2) (time t4, t12). At times t4 and t12, the generated power P1 becomes the peak power P12.

  Assuming that the time from when the charge / discharge power conditioner 4 increases the effective value of the output voltage V1 until the effective value of the output voltage V1 reaches the suppression start voltage V12 is the output voltage increase time T1, this output voltage increase time T1 should be as short as possible. For this reason, it is preferable that the first rate of increase is set as high as possible. However, the time from when the effective value of the output voltage V1 exceeds the suppression start voltage V12 until the solar cell power conditioner 2 starts suppressing the power output (suppression start delay T2) is different for each solar cell power conditioner 2. Variation is large. For this reason, if the power conditioner 4 for charging / discharging continues to raise the effective value of the output voltage V1 at the first rate of increase, the power for charging / discharging is started before the solar cell power conditioner 2 starts suppressing the power output. The effective value of the output voltage V1 of the conditioner 4 reaches the overvoltage abnormal voltage V13 of the solar cell power conditioner 2, and the solar cell power conditioner 2 stops outputting power.

  Therefore, in the present embodiment, the switching voltage (second threshold value) V14 is set in advance between the suppression start voltage V12 and the overvoltage abnormal voltage V13. When the effective value of the output voltage V1 reaches the switching voltage V14 (time t3, t11), the charge / discharge power conditioner 4 sets the effective value of the output voltage V1 at a second rate of increase that is lower than the first rate of increase. Raise. Note that the switching voltage V14 is set in consideration of variations in the suppression start voltage V12. In addition, the first increase rate and the second increase rate are set so that the effective value of the output voltage V1 does not become the overvoltage abnormal voltage V13.

  As a result, even if the suppression start delay T2 of the solar cell power conditioner 2 varies, the effective value of the output voltage V1 of the charge / discharge power conditioner 4 does not reach the overvoltage abnormal voltage V13. The power output can be suppressed.

  When the solar cell power conditioner 2 suppresses the power output and the generated power P1 of the solar cell 21 becomes equal to or less than the load power P11 (time t5), the charging / discharging is performed so that the effective value of the output voltage V1 becomes the rated voltage V11. The power conditioner 4 gradually decreases the effective value of the output voltage V1 (time t5 to t8). At this time, the charge / discharge power conditioner 4 decreases the effective value of the output voltage V1 at the first decrease rate until the effective value of the output voltage V1 becomes the switching voltage V14 (time t5 to t6). . When the effective value of the output voltage V1 becomes equal to or lower than the switching voltage V14 (time t6), the charging / discharging power conditioner 4 decreases the effective value of the output voltage V1 at a second decrease rate higher than the first decrease rate. (Time t6 to t7). At time t8, the solar cell power conditioner 2 ends the suppression of the power output with a suppression end delay T3.

  By the way, as an example of a method of changing the effective value of the output voltage V1 of the charge / discharge power conditioner 4, there are the following three methods. Any method may be adopted, and it is appropriately selected according to the application.

  First, as a first method, as shown in FIG. 4, there is a method of changing the effective value by changing the amplitude of the output voltage V1, which is an AC voltage. In this method, the output control unit of the charge / discharge power conditioner 4 changes the effective value of the output voltage V1 by changing the amplitude of the output voltage V1. Specifically, the output control unit can change the amplitude of the output voltage V <b> 1 by adjusting the on-time pulse width of the switching elements 491 to 494 of the DC / AC bidirectional conversion unit 48. At this time, the output control unit sets the ON time of the switching elements 472 and 473 of the DC / DC bidirectional converter 47 so that the output voltage of the DC / DC bidirectional converter 47 is higher than the instantaneous value of the output voltage V1. Adjust the pulse width. 4 indicates the output voltage V1 before the change, and the solid line in FIG. 4 indicates the output voltage V1 after the change.

  Subsequently, as a second method, as shown in FIG. 5, there is a method of changing the effective value of the output voltage V1 without changing the peak value of the output voltage V1 before and after the change. In the case of the amplitude amplification type as in the first method, the peak value of the output voltage V1 after the change is high because the amplitude is increased from the broken line waveform in FIG. 4 to produce the solid line waveform in FIG. Thus, a problem relating to the breakdown voltage of the load 8 occurs. For this reason, it is necessary not to connect the load device 81 having a breakdown voltage lower than the peak value of the output voltage V1 after the change.

  Therefore, in the second method, the output control unit of the power conditioner 4 for charging / discharging is a sine wave (dashed line in FIG. 5) that is a wave whose instantaneous value is zero at the peak point of the sine wave (the dashed line in FIG. 5). ) Is changed to a waveform equivalent to the waveform (solid line in FIG. 5) superimposed on the output voltage V1, thereby changing the effective value of the output voltage V1. That is, the solid line waveform in FIG. 5 is created by combining the dashed-line sine wave in FIG. Specifically, the output control unit adjusts the pulse width of the on-time of the switching elements 491 to 494 of the DC / AC bidirectional conversion unit 48 to change the waveform of the output voltage V1 to the solid line waveform of FIG. be able to. Thereby, it is possible to increase only the effective value of the output voltage V1 without increasing the peak value of the output voltage V1 by a simple calculation.

  However, in the second method, as shown in FIG. 5, for the positive waveform portion of the basic sine wave, the two waveforms of the alternate long and short dashed lines are also positive waveforms, and the basic sine wave Of these, for the negative waveform portion, it is desirable that the two waveforms of the alternate long and short dash line are also negative waveforms.

  In particular, the output controller of the charge / discharge power conditioner 4 changes the waveform of the output voltage V1 to a waveform equivalent to a waveform in which the second harmonic is superimposed on the fundamental wave as a sine wave, as shown in FIG. Thus, it is preferable to change the effective value of the output voltage V1.

  Subsequently, as a third method, as shown in FIG. 6, there is a method of changing the effective value by setting a voltage of a waveform generated by applying a gain G that differs depending on the phase of the sine wave to the sine wave. . In this method, the output control unit of the charge / discharge power conditioner 4 has a waveform equivalent to a waveform (solid line in FIG. 6) obtained by amplifying a sine wave (broken line in FIG. 6) with a gain G that differs depending on the phase of the sine wave. The effective value of the output voltage V1 is changed by changing the waveform of the output voltage V1. Specifically, the output control unit adjusts the on-time pulse width of the switching elements 491 to 494 of the DC / AC bidirectional conversion unit 48 to change the waveform of the output voltage V1 to the waveform of the solid line in FIG. be able to. Thereby, it is possible to increase only the effective value of the output voltage V1 without increasing the peak value of the output voltage V1 by a simple calculation.

  Next, operation | movement of the electric power supply system 1 which concerns on this embodiment is demonstrated using FIG. Reference numerals refer to FIG. First, the power supply system 1 performs an interconnection operation with the commercial power system 7 during normal time when the commercial power system 7 supplies commercial power (S1). The power supply system 1 continues the interconnection operation unless a power failure of the commercial power system 7 is detected (S2). On the other hand, when the commercial power system 7 fails, the solar cell power conditioner 2, the fuel cell power conditioner 3, and the charge / discharge power conditioner 4 detect the power failure of the commercial power system 7 by the power failure detection function. System operation (power output) is stopped (S3). Thereafter, the first switch 51 is turned off by the off signal from the charge / discharge power conditioner 4 to electrically disconnect the commercial power supply path 91, and the power supply system 1 is switched to the self-sustaining operation mode (S4). Independent operation is performed (S5). At this time, the charge / discharge power conditioner 4 outputs an AC voltage having the same frequency and amplitude as the AC voltage of the commercial power system 7 in a normal state. As a result, the solar cell power conditioner 2 and the fuel cell power conditioner 3 resume operation in the same manner as in the normal state. Thereafter, the power supply system 1 performs suppression control according to the state of charge of the storage battery 41 (S6). Thereafter, when power recovery of the commercial power system 7 is detected (S7), the power supply system 1 stops the independent operation (power output) (S8), and switches from the independent operation to the grid interconnection operation (S9). On the other hand, when the power recovery of the commercial power system 7 is not detected in step S7, the process returns to step S6 and the suppression control is continued.

  Next, the suppression control operation in step S6 will be described with reference to FIG. Reference numerals refer to FIGS. First, when the charging power of the storage battery 41 exceeds the set value (S21), until the effective value of the output voltage V1 of the charging / discharging power conditioner 4 reaches the switching voltage V14 (S22), the charging / discharging power conditioner. 4 increases the effective value of the output voltage V1 at the first rate of increase (S23). When the effective value of the output voltage V1 exceeds the switching voltage V14 (S22), the effective value of the output voltage V1 is increased at the second increase rate (<first increase rate) (S24).

  On the other hand, when the charging power is not more than the set value in step S21, when the effective value of the output voltage V1 of the charging / discharging power conditioner 4 is larger than the rated voltage V11 and the switching voltage V14 (S25, S26), the charging / discharging power. The conditioner 4 decreases the effective value of the output voltage V1 at the first decrease rate (S27). If the effective value of the output voltage V1 is equal to or lower than the switching voltage V14 in step S26, the effective value of the output voltage V1 is decreased at the second decreasing rate (> first decreasing rate) (S28). When the effective value of the output voltage V1 is equal to or lower than the rated voltage V11 in step S25, the suppression control operation is terminated.

  The charge / discharge power conditioner 4 in the present embodiment described above controls the output voltage V1 on the power supply path 92 side so that the power supply path voltage V2 becomes a predetermined voltage at the time of a power failure of the commercial power system 7. Thereby, in the power supply system 1 of the present embodiment, the power conditioners for power generation (solar cell power conditioner 2 and fuel cell power conditioner 3) are supplied to the power supply path 92 as in the case where the commercial power system 7 has not failed. Can output power. As a result, in the power supply system 1 of the present embodiment, even if the power generator for power generation does not have a communication function, the power generation apparatus (solar cell) is not required to be manually operated during a power failure of the commercial power system 7. 21, fuel cell) can be used.

  Further, in the power supply system 1 of the present embodiment, when the storage battery 41 is not charged normally, the charging / discharging power conditioner 4 reduces the effective value of the output voltage V1 to the suppression start voltage (threshold) V12. Make it bigger. Thereby, in the power supply system 1 of this embodiment, since the effective value of the feed path voltage V2 can be made larger than the suppression start voltage V12, the output power of the power conditioner for power generation can be reduced, and as a result. The storage battery 41 can be charged under normal conditions.

  Furthermore, according to the power supply system 1 of the present embodiment, when the effective value of the output voltage V1 of the charge / discharge power conditioner 4 exceeds the switching voltage (second threshold value) V14, the effective value of the output voltage V1. Reduce the rate of increase. Thereby, in the power supply system 1 of the present embodiment, even if the start of the function of suppressing the power output (suppression start delay T2) varies between the power generators for power generation, the effective value of the power supply path voltage V2 is generated. The output power of the power generator for power generation can be reduced without reaching the overvoltage abnormal voltage (abnormal stop value) V13 of the power inverter for power generation.

  Further, according to the power supply system 1 of the present embodiment, the effective value of the output voltage V1 can be easily changed by changing the amplitude of the output voltage V1 of the charge / discharge power conditioner 4.

  In the power supply system 1 of the present embodiment, the waveform of the output voltage V1 is changed to a waveform equivalent to a waveform in which a wave whose instantaneous value is zero at the peak point of the sine wave is superimposed on the sine wave. Thereby, it is possible to increase only the effective value of the output voltage V1 while keeping the peak value of the output voltage V1 constant. In particular, by changing the waveform of the output voltage V1 to a waveform equivalent to a waveform obtained by superimposing twice the harmonics on the fundamental wave, the output voltage V1 can be set with a constant peak value of the output voltage V1 by a simple calculation. Only the effective value can be increased.

  In the power supply system 1 of the present embodiment, the waveform of the output voltage V1 is changed to a waveform equivalent to a waveform obtained by amplifying a sine wave with a gain G that differs depending on the phase of the sine wave. Thereby, it is possible to increase only the effective value of the output voltage V1 with a simple calculation while keeping the peak value of the output voltage V1 constant.

(Embodiment 2)
The power supply system 1 according to the second embodiment relates to the first embodiment in that when the charging power is equal to or higher than the specified power and the change direction is negative, the voltage control is performed without changing the effective value of the output voltage V1. Different from the power supply system 1. In addition, about the component similar to the electric power supply system 1 of Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The control unit 43 of the charge / discharge power conditioner 4 of the present embodiment functions as a power change detection unit that detects the change direction of the increase / decrease in the charge power. Moreover, the control part 43 of this embodiment is an effective value of output voltage V1, when it is detected that charging power is a decreasing direction by a power change detection part in a state with charging power more than regulation power as an output control part. Is maintained at the value at the time of detection. Note that a description of the same functions as those of the control unit 43 of the first embodiment will be omitted.

  Next, an example of operation | movement of the electric power supply system 1 which concerns on this embodiment is demonstrated using FIG. The speed of the output suppression of the solar cell power conditioner 2 is greatly different for each product. For this reason, even if the solar cell power conditioner 2 starts to be suppressed so that the output power of the solar cell power conditioner 2 becomes equal to or less than the load power P11, the time until the suppression (inhibition start delay T2) varies greatly. . Thereby, it is conceivable that the charge / discharge power conditioner 4 increases the effective value of the output voltage V1 to the overvoltage abnormal voltage V13 with the suppression start delay T2.

  Therefore, it is determined whether the charging power is increasing or decreasing on the charging / discharging power conditioner 4 side, thereby determining whether or not the solar cell power conditioner 2 has started suppression. In accordance with this determination result, the charge / discharge power conditioner 4 changes the rate of increase in the effective value of the output voltage V1. An example of the increase rate of the effective value of the output voltage V1 of the charge / discharge power conditioner 4 will be shown below. Hereinafter, although the solar cell power conditioner 2 will be described, the same applies to the fuel cell power conditioner 3.

  The output power of the solar battery power conditioner 2 (the generated power P1 of the solar battery 21) is larger than the load power P11, the generated power P1 is increasing, that is, the charging power of the storage battery 41 is increasing, and the effective value of the output voltage V1 Is smaller than the switching voltage V14 (time t21 to t23, t28 to t30 in FIG. 9), the effective value of the output voltage V1 is set as the first rate of increase. Further, when the generated power P1 is larger than the load power P11, the generated power P1 is increasing, that is, the charging power is increasing, and the effective value of the output voltage V1 is larger than the switching voltage V14 (time t23 to t24, t30 to t31). ), The effective value of the output voltage V1 is the second rate of increase. On the other hand, when the generated power P1 is larger than the load power P11, the generated power P1 is decreasing, that is, the charging power is decreasing, and the effective value of the output voltage V1 is larger than the switching voltage V14 (time t24 to t25, t31 to t32). ), The effective value of the output voltage V1 is the third rate of increase. Although not shown, when the generated power P1 is larger than the load power P11, the generated power P1 is decreasing, and the effective value of the output voltage V1 is smaller than the switching voltage V14, the effective value of the output voltage is increased by a fourth value. Rate. The first increase rate> the second increase rate> the third increase rate / the fourth increase rate ≧ 0. Further, when the third rate of increase and the fourth rate of increase are 0, as shown in FIG. 9, the effective value of the output voltage V1 becomes constant after the second rate of increase (the third rate of increase). = 0), and in some cases, suddenly increases from the first rate of increase (fourth rate of increase = 0).

  When the solar cell power conditioner 2 suppresses the power output and the generated power P1 of the solar cell 21 becomes equal to or less than the load power P11 (time t25, t32), the charging is performed so that the effective value of the output voltage V1 becomes the rated voltage V11. The discharge power conditioner 4 gradually decreases the effective value of the output voltage V1 (time t25 to t27). At this time, until the effective value of the output voltage V1 becomes the switching voltage V14, the charge / discharge power conditioner 4 decreases the effective value of the output voltage V1 at the first decrease rate (time t25 to t26, t32 to t33). When the effective value of the output voltage V1 becomes equal to or lower than the switching voltage V14 (time t26, t33), the charge / discharge power conditioner 4 sets the effective value of the output voltage V1 at a second decrease rate higher than the first decrease rate. It is lowered (time t26 to t27). At time t27, the solar cell power conditioner 2 ends the suppression of the power output with a suppression end delay T3.

  Next, the suppression control operation of the power supply system 1 according to the present embodiment will be described with reference to FIG. Reference numerals refer to FIGS. First, when the charging power of the storage battery 41 exceeds the set value (S41), the charging power is increasing (S42), and the effective value of the output voltage V1 of the charging / discharging power conditioner 4 reaches the switching voltage V14. Until (S43), the charge / discharge power conditioner 4 increases the effective value of the output voltage V1 at the first increase rate (S44). When the effective value of the output voltage V1 exceeds the switching voltage V14 (S43), the charge / discharge power conditioner 4 increases the effective value of the output voltage V1 at the second increase rate (<first increase rate) ( S45).

  When the charging power is not increasing in step S42, when the effective value of the output voltage V1 is larger than the switching voltage V14 (S46), the charging / discharging power conditioner 4 has a third rate of increase (<second rate of increase). The effective value of the output voltage V1 is increased by (rate) (S47). When the third increase rate = 0, the effective value of the output voltage V1 is maintained. When the effective value of the output voltage V1 exceeds the switching voltage V14 (S46), the charge / discharge power conditioner 4 increases the effective value of the output voltage V1 at the fourth increase rate (<first increase rate) ( S48). When the fourth increase rate = 0, the effective value of the output voltage V1 is maintained.

  On the other hand, when the charging power is equal to or lower than the set value in step S41, when the effective value of the output voltage V1 is larger than the rated voltage V11 and the switching voltage V14 (S49, S50), the charging / discharging power conditioner 4 is the first The effective value of the output voltage V1 is decreased at the decreasing rate (S51). When the effective value of the output voltage V1 is equal to or lower than the switching voltage V14 (S50), the charge / discharge power conditioner 4 decreases the effective value of the output voltage V1 at the second decrease rate (S52). If the effective value of the output voltage V1 is equal to or lower than the rated voltage V11 in step S49, the suppression control operation is terminated.

  According to the power supply system 1 of the present embodiment described above, whether or not the power generator for power generation (solar cell power conditioner 2 and fuel cell power conditioner 3) has started output suppression is determined. The na 4 makes a determination based on the change direction of the charging power, and the effective value of the output voltage V1 can be made constant according to the determination result. Thereby, in the power supply system 1 of the present embodiment, the probability that the power supply path voltage V2 reaches the overvoltage abnormal voltage (abnormal stop value) V13 can be reduced.

(Embodiment 3)
In the power supply system 1 according to the third embodiment, when the charging power P2 rapidly increases as shown in FIG. 12, the power generation switching unit (second switch 52, third switch 53) shown in FIGS. It is different from the power supply system 1 according to the second embodiment in that the power output from the power conditioner for power generation (solar cell power conditioner 2, fuel cell power conditioner 3) is stopped by control. In addition, about the component similar to the electric power supply system 1 of Embodiment 2, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The control part 43 of the power conditioner 4 for charging / discharging of this embodiment functions as a below-mentioned calculation part and a stop control part. Hereinafter, the calculation unit and the stop control unit will be described with reference to FIGS.

  The calculation unit calculates the charging power P <b> 2 when charging the storage battery 41.

  The stop control unit charges / discharges from the solar cell power conditioner 2 and the fuel cell power conditioner 3 when the charging power P2 calculated by the calculation unit increases at a predetermined rate of change or more and becomes equal to or more than the specified power. The power output to the power conditioner 4 is stopped.

  The stop control unit of the present embodiment electrically connects the solar cell power conditioner 2, the fuel cell power conditioner 3, and the power supply path 92 when the charging power P <b> 2 increases at the above change rate and exceeds the specified power. The second switch 52 and the third switch 53 are controlled so as to be disconnected.

  Next, an example of the operation of the power supply system 1 according to the present embodiment will be described with reference to FIG. First, the change in the output power due to sunshine of the solar cell power conditioner 2 is a relatively gradual output fluctuation. In particular, the increase in output power depends on the change in sunshine and the follow-up speed of the maximum power follow-up control (MPPT control) of the solar battery power conditioner 2, so that the power conditioner 4 for charging / discharging is gradually changed by the output suppression function. It is possible to control the charging power P2. On the other hand, the fluctuation of the load device 81 causes an extremely steep fluctuation of the charging power P2 of the charging / discharging power conditioner 4 (time t41 to t44). For example, when the 1 kW load device 81 is turned off from on (time t41), the charging power P2 of the charging / discharging power conditioner 4 suddenly increases by 1 kW (time t43). Even if the output suppression function of the solar cell power conditioner 2 is operated in this state, the charge / discharge power conditioner 4 is overcharged until the suppression of 1 kW works.

  Therefore, the charging / discharging power conditioner 4 detects the steep charging power P2, and when the charging power P2 exceeds the allowable charging power P21, the second charging power conditioner 2 is used to quickly disconnect the solar battery power conditioner 2 from the power supply path 92. An OFF signal is output to the switch 52 (time t42 to t45).

  Next, the suppression control operation of the power supply system 1 according to the present embodiment will be described with reference to FIG. Reference numerals refer to FIGS. First, the case where the charging power P2 exceeds the set value (S61), the charging power P2 is increasing (S62), and the increasing speed of the charging power P2 is equal to or less than the setting value (S63) will be described. Until the effective value of the output voltage V1 reaches the switching voltage V14 (S64), the charge / discharge power conditioner 4 increases the effective value of the output voltage V1 at the first increase rate (S65). When the effective value of the output voltage V1 exceeds the switching voltage V14 (S64), the charge / discharge power conditioner 4 increases the effective value of the output voltage V1 at the second increase rate (<first increase rate) ( S66).

  If the increase speed of the charging power P2 exceeds the set value in step S63, the second switch 52 for disconnecting the solar cells 21 is turned off (S67).

  When the charging power P2 is not increasing in step S62, when the effective value of the output voltage V1 is larger than the switching voltage V14 (S68), the charging / discharging power conditioner 4 has a third rate of increase (<second The effective value of the output voltage V1 is increased at the rate of increase) (S69). When the effective value of the output voltage V1 is equal to or lower than the switching voltage V14 (S68), the charge / discharge power conditioner 4 increases the effective value of the output voltage V1 at the fourth increase rate (<first increase rate). (S70).

  On the other hand, when the charging power P2 is equal to or lower than the set value in step S61, when the effective value of the output voltage V1 is larger than the rated voltage V11 and the switching voltage V14 (S71, S72), the charging / discharging power conditioner 4 is the first The effective value of the output voltage V1 is decreased at a decreasing rate of (S73). When the effective value of the output voltage V1 is equal to or lower than the switching voltage V14 (S72), the charge / discharge power conditioner 4 decreases the effective value of the output voltage V1 at the second decrease rate (S74). If the effective value of the output voltage V1 is equal to or lower than the rated voltage V11 in step S71, the suppression control operation is terminated.

  According to the power supply system 1 of the present embodiment described above, the charging / discharging power conditioner 4 detects the steep charging power P2 when the steep fluctuation of the charging power P2 occurs, and promptly generates power. The power output from the conditioner (solar cell power conditioner 2, fuel cell power conditioner 3) to the charge / discharge power conditioner 4 can be stopped.

  In particular, in the power supply system 1 of the present embodiment, when a sudden change in the charging power P2 of the charging / discharging power conditioner 4 occurs, the charging / discharging power conditioner 4 operates as a power generation switching unit (second switch). 52, by controlling the third switch 53), the power output from the power conditioner for power generation to the power conditioner 4 for charge / discharge can be stopped reliably and easily.

(Embodiment 4)
As shown in FIG. 14, in the power supply system 1 according to the fourth embodiment, when the charging power P2 increases rapidly, the effective value of the output voltage V1 is set to the overvoltage abnormal voltage V13 or more, and the solar cell power conditioner 2 and the fuel cell It is different from the power supply system 1 according to the third embodiment in that the power output from the power conditioner 3 is stopped. In addition, about the component similar to the power supply system 1 of Embodiment 3, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The solar cell power conditioner 2 and the fuel cell power conditioner 3 of the present embodiment stop the power output when the effective value of the power supply path voltage V2 exceeds a predetermined overvoltage abnormal voltage (abnormal stop value) V13. Has an abnormal stop function. In addition, description is abbreviate | omitted about the function similar to the solar cell power conditioner 2 and the fuel cell power conditioner 3 of Embodiment 3. FIG.

  The stop control unit of the control unit 43 of the charge / discharge power conditioner 4 of the present embodiment, when the charging power P2 increases at a predetermined change rate or more and becomes an allowable charging power (specified power) P21 or more, The output control unit is controlled so that the effective value of the output voltage V1 is larger than the overvoltage abnormal voltage V13. Thereby, the electric power output from the solar cell power conditioner 2 and the fuel cell power conditioner 3 is stopped. In addition, description is abbreviate | omitted about the function similar to the power conditioner 4 for charging / discharging of Embodiment 3. FIG.

  Next, an example of the operation of the power supply system 1 according to the present embodiment will be described with reference to FIG. First, the change in the output power due to sunshine of the solar cell power conditioner 2 is a relatively gradual output fluctuation. In particular, the increase in output power depends on the change in sunshine and the follow-up speed of the maximum power follow-up control (MPPT control) of the solar battery power conditioner 2, so that the power conditioner 4 for charging / discharging is gradually changed by the output suppression function. It is possible to control the charging power P2. On the other hand, the fluctuation of the load device 81 causes a very steep fluctuation of the charging power P2 of the charging / discharging power conditioner 4 (time t61 to t63). For example, when the 1 kW load device 81 is turned off from on (time t61), the charging power P2 of the charge / discharge power conditioner 4 suddenly increases by 1 kW (time t62). Even if the output suppression function of the solar cell power conditioner 2 is operated in this state, the charge / discharge power conditioner 4 is overcharged until the suppression of 1 kW works.

  Therefore, the charging / discharging power conditioner 4 detects the steep charging power P2, and when the charging power P2 exceeds the allowable charging power P21, the charging / discharging power conditioner 4 is promptly stopped. The effective value of the output voltage V1 of the conditioner 4 is increased to the overvoltage abnormal voltage V13 (time t61 to t62). At time t64 after time t63, the output voltage V1 is returned to the rated voltage V11.

  Next, the suppression control operation of the power supply system 1 according to the present embodiment will be described with reference to FIG. Reference numerals refer to FIGS. First, the case where the charging power P2 exceeds the set value (S81), the charging power P2 is increasing (S82), and the increasing speed of the charging power P2 is equal to or lower than the setting value (S83) will be described. Until the effective value of the output voltage V1 reaches the switching voltage V14 (S84), the charge / discharge power conditioner 4 increases the effective value of the output voltage V1 at the first increase rate (S85). When the effective value of the output voltage V1 exceeds the switching voltage V14 (S84), the charge / discharge power conditioner 4 increases the effective value of the output voltage V1 at the second increase rate (<first increase rate) ( S86).

  When the increase speed of the charging power P2 exceeds the set value in step S83, the process proceeds to step S85.

  When the charging power P2 is not increasing in step S82, when the effective value of the output voltage V1 is larger than the switching voltage V14 (S87), the charging / discharging power conditioner 4 has a third rate of increase (<second The effective value of the output voltage V1 is increased at the rate of increase) (S88). When the effective value of the output voltage V1 is equal to or lower than the switching voltage V14 (S87), the charge / discharge power conditioner 4 increases the effective value of the output voltage V1 at the fourth increase rate (<first increase rate). (S89).

  On the other hand, when the charging power P2 is equal to or lower than the set value in step S81, when the effective value of the output voltage V1 is larger than the rated voltage V11 and the switching voltage V14 (S90, S91), the charging / discharging power conditioner 4 is the first The effective value of the output voltage V1 is decreased at a decrease rate of (S92). When the effective value of the output voltage V1 is equal to or lower than the switching voltage V14 (S91), the charge / discharge power conditioner 4 decreases the effective value of the output voltage V1 at the second decrease rate (S93). When the effective value of the output voltage V1 is equal to or lower than the rated voltage V11 in step S90, the suppression control operation is terminated.

  In the power supply system 1 of the present embodiment described above, when the charging power P2 increases rapidly, the effective value of the output voltage V1 of the charging / discharging power conditioner 4 is calculated as the power generating conditioner (solar cell power conditioner). 2. Overvoltage abnormal voltage (abnormal stop value) V13 of the fuel cell power conditioner 3) is increased. Thereby, in the power supply system 1 of the present embodiment, the effective value of the power supply path voltage V2 can be made larger than the overvoltage abnormal voltage V13, so that the power output of the power generator for power generation can be stopped reliably and easily. it can.

  In each embodiment, the first switch (switching unit) 51, the second switch (power generation switching unit) 52, and the third switch (power generation switching unit) 53 are 1 as in each embodiment. The two switching panels 5 may be provided together or may be provided separately.

  In each embodiment, the power generator and the power conditioner for power generation may be singular or plural. Further, there may be a plurality of types of power generation devices.

  Furthermore, in each embodiment, the distribution board 6 is located in front of the load 8 on the power supply path 92. However, the power conditioner for power generation (solar cell power conditioner 2, fuel cell power conditioner 3) and power for charge / discharge are included. The conditioner 4 may be directly connected to the distribution board 6 or may be connected to the distribution board 6 via the switching board 5.

  While the invention has been described in terms of several preferred embodiments, various modifications and variations can be made by those skilled in the art without departing from the true spirit and scope of the invention, ie, the claims.

Claims (13)

A power conditioner for power generation for controlling the power generation of the power generation device, a power conditioner for charge / discharge for controlling charge / discharge of the storage battery, a switching unit inserted in a commercial power supply path for feeding power from the commercial power system, A detection unit for detecting power recovery of the commercial power system,
The power generation power conditioner outputs power to the power supply path when a predetermined voltage is applied to the power supply path for supplying power to the load from the power generation power conditioner and the charge / discharge power conditioner. And a function of stopping power output to the power supply path when the predetermined voltage is not applied to the power supply path,
The switching unit electrically disconnects the commercial power supply path when the commercial power system has a power failure, and electrically connects the commercial power supply path when the detection unit detects power recovery of the commercial power system. connection,
The charge / discharge power conditioner has an output control unit that controls power output to the power supply path, and a power failure detection unit that detects a power failure of the commercial power system,
The output control unit is configured to set the voltage of the power supply path to the predetermined voltage when a power failure of the commercial power system is detected by the power failure detection unit and the commercial power supply path is electrically disconnected by the switching unit. An effective value of an output voltage output from the charging / discharging power conditioner toward the feeding path for discharging is changed. The power generator for power generation has a function of suppressing power output to the power supply path when an effective value of the voltage of the power supply path is larger than a predetermined threshold value,
The output control unit of the charge / discharge power conditioner is configured such that when a power failure of the commercial power system is detected by the power failure detection unit and the commercial power supply path is electrically disconnected by the switching unit, When charging satisfies a normal condition, the effective value of the output voltage is set to be equal to or less than the threshold value. When charging of the storage battery does not satisfy a normal condition, the effective value of the output voltage is set to be larger than the threshold value. The power supply system according to claim 1. The charging / discharging power conditioner has a calculating unit that calculates charging power when charging the storage battery,
The output control unit increases the effective value of the output voltage at a predetermined first increase rate when the charging power calculated by the calculating unit is equal to or higher than a specified power, and the charging power is set to the specified power. When the effective value of the output voltage exceeds a second threshold value that is greater than the threshold value, the effective value of the output voltage is greater than zero and lower than the first increase rate. The effective value of the output voltage is decreased when the charging power becomes less than the specified power while the effective value of the output voltage is larger than the second threshold value. 2. The power supply system according to 2. The charge / discharge power conditioner has a power change detection unit that detects a change direction of increase / decrease in the charge power,
The output control unit sets the effective value of the output voltage to a value at the time of detection when the power change detection unit detects that the charging power is decreasing in the state where the charging power is equal to or higher than the specified power. The power supply system according to claim 3, wherein the power supply system is maintained. The charge / discharge power conditioner is:
A calculation unit for calculating charging power when charging the storage battery;
Stops the power output from the power generator for power generation to the power conditioner for charging / discharging when the charging power calculated by the calculating unit increases at a predetermined rate of change or more and reaches a specified power or more. The power supply system according to claim 1, further comprising: a stop control unit that controls the power supply system.   The charge / discharge power conditioner increases the charge power calculated by the calculation unit at a predetermined rate of change or more and reaches a specified power or more from the power generation conditioner for charge / discharge. 5. The power supply system according to claim 3, further comprising a stop control unit that stops power output to the power conditioner. A power generation switching unit inserted between the power generation power conditioner and the power supply path,
The stop control unit of the charge / discharge power conditioner electrically connects the power generator for power generation and the power supply path when the charge power increases at the change rate or more and becomes the specified power or more. The power supply system according to claim 5 or 6, wherein the power generation switching unit is controlled to be disconnected. The power generator for power generation has a function of stopping power output when an effective value of the voltage of the power supply path exceeds a predetermined abnormal stop value,
The stop control unit of the charge / discharge power conditioner increases an effective value of the output voltage from the abnormal stop value when the charge power increases at the change rate or more and becomes the specified power or more. The power supply system according to claim 5, wherein the output control unit is controlled.   The output controller of the charge / discharge power conditioner changes an effective value of the output voltage by changing an amplitude of the output voltage. The power supply system described.   The output control unit of the charge / discharge power conditioner changes the waveform of the output voltage to a waveform equivalent to a waveform in which a wave having an instantaneous value of zero is superimposed on a sine wave at the peak point of the sine wave. The power supply system according to any one of claims 1 to 8, wherein an effective value of the output voltage is changed.   The output controller of the charge / discharge power conditioner changes the waveform of the output voltage to a waveform equivalent to a waveform obtained by superimposing a double harmonic on the fundamental wave as the sine wave. The power supply system according to claim 10, wherein an effective value is changed.   The output control unit of the charge / discharge power conditioner changes the waveform of the output voltage to a waveform equivalent to a waveform obtained by amplifying a sine wave with a gain different depending on the phase of the sine wave, thereby determining the effective output voltage. The power supply system according to any one of claims 1 to 8, wherein a value is changed.   The power conditioner for charging / discharging used for the electric power supply system of any one of Claims 1-12.

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