JP5947736B2 - Power supply system, power supply control program, and power supply control method - Google Patents

Description

The present invention relates to a power supply system including a stationary power generator such as a fuel cell cogeneration system (hereinafter simply referred to as “FC system”), a power supply control program, and a power supply control method.

  The FC system generates power according to the amount of power load measured by the current sensor and supplies the power to the power load. In general, the FC system includes a current type inverter and generates power using a system voltage. When a power failure occurs in the grid power, the FC system loses the voltage source and stops generating power.

  Therefore, when the storage battery system is combined with the FC system and the system power supply fails, if the power is supplied from the storage battery system to the FC system, the FC system can continue power generation. Thereby, at the time of a power failure of a system power supply, it is possible to feed the generated power of the FC system to the power load.

It is known that power is supplied to a load by a combination of a photovoltaic power generation device and a storage battery at the time of a power failure of the system power supply (for example, Patent Document 1).

JP 2012-44733 A

  By the way, in a power feeding system including a storage battery system and an FC system, the power consumption of the power load is covered by each power of the system, the storage battery system, and the FC system during grid connection. In this case, if the total impedance from the storage battery system to the power load is Z1, and the total impedance from the FC system to the power load is Z2, Z2 is smaller than Z1, and Z1> Z2 is established.

  At the time of a power failure of the system power supply, if the system power supply is disconnected and the FC system is generated by obtaining power from the storage battery system, both the generated power of the FC system and the power of the storage battery system can be supplied to the power load. .

  The electric power load to which such electric power is supplied includes a special load (special electric power load) that instantaneously consumes a large current during rapid cooling, such as an electric refrigerator. When a large current flows through such a special power load, there is a problem that the power quality from the FC system is instantaneously lowered. That is, when the special power load instantaneously consumes a large current in a state where Z1> Z2 is satisfied, a large current is supplied to the special power load from the FC system having a low impedance.

  When a large current is consumed from the FC system side, the output voltage of the FC system is lowered, the power quality is lowered, and the protection function is activated. In other words, when the output voltage of the FC system is disturbed, the FC system detects the isolated operation, stops the power generation for a certain period of time, or stops the error depending on the number of detected independent operations or the continuous operation detection. Wake up. If the instantaneous large current is not consumed, the generated power of the FC system can be supplied to the power load. On the other hand, because of the instantaneous large current supply, the generated power of the FC system cannot be used during a power failure of the system power supply. There is a problem.

  However, protection functions such as an independent operation detection function are indispensable for grid connection in the distributed power supply of the FC system and storage battery system linked to the grid power supply. Satisfaction of the grid interconnection regulations is essential, and no change or invalidation of operating conditions for the protection function of the distributed power supply is allowed in the grid interconnection state.

  When the power generated by the FC system is used in the event of a power failure of the system power supply, if the power generation of the FC system stops, the power generated by the FC system cannot be used, the burden on the storage battery increases, and the consumption of the storage battery becomes significant. There are challenges.

  Such a problem occurs not only in the FC system but also in other distributed power sources that include power generation means such as solar power generation in the power storage means.

Accordingly, an object of the present invention is to improve the continuity and stability of power supply to a power load in a power supply system having a distributed power source including a power storage unit and a power generation unit at the time of a power failure of a system power source.

To achieve the above object, a power supply system of the present invention is connected to a power distribution system which is powered from the system power supply, with distributed power supply including a power storage means and the generator means, a power failure or autonomous operation of the distributed power of the system power supply when, the accumulator-side powers in the distribution system from the dispersed power source by Rukoto turn into low impedance from the power generating means side, or the power generating means side from the dispersed power source by more high impedance turn into Rukoto the accumulator unit supplies power to the power distribution system, or the power storage unit side turned into a low impedance from the power generating means side, and for feeding said power generating means side by Rukoto turn into high impedance from said storage means from said dispersed power source to the power distribution system.

In the power supply system, a detection unit that detects a power failure of a system power supply or a self-sustained operation of the distributed power source, and an impedance on the power storage unit side lower than that of the power generation unit by the power failure detection or the self-sustained operation detection of the detection unit. low impedance circuit that turn into or the power generating means side of the high-impedance circuit that turn into high impedance from said storage means the impedance or the accumulator side of the impedance low impedance circuit and said that turn into low impedance from the power generating means, the impedance of the power generator side a, and a high impedance circuit that turn into high impedance from the accumulator unit.

In the power feeding system, the low impedance circuit includes an inductor connected in series to the power storage unit, a capacitor connected in parallel to the power storage unit, or an inductor connected in series to the power storage unit and the power storage unit. A capacitor connected in parallel may be included.

In the power supply system, it said high impedance circuit comprises an inductor and said power generating means is connected in series with the inductor connected in series to the power generating means or capacitor is connected in parallel to the power generating unit, or the power generating means, A capacitor connected in parallel may be included.

To achieve the above object, a power supply control program for a power supply system according to the present invention is executed on a computer mounted on a power supply system that is connected to a power distribution system that is supplied with power from a system power supply and that includes a distributed power source including a power storage unit and a power generation unit. A power supply control program for generating power, and generating impedance switching information based on detection information of a power failure of a system power supply or a self-sustained operation of the distributed power source, and lowering the impedance on the power storage means side than the power generating means based on the impedance switching information. impedance turned into, or turned into a high impedance from said storage means the impedance of the power generating means side, or the turned into a low-impedance than the impedance of the power storage unit side said power generating means, and turn into high impedance from said storage means the impedance of the power generating means side The

In order to achieve the above object, a power feeding control method for a power feeding system according to the present invention is a power feeding control method for a power feeding system that is connected to a power distribution system fed from a system power source and includes a distributed power source including a power storage unit and a power generation unit. , Detecting a power failure of a system power supply or a self-sustained operation of the distributed power supply, and by detecting the power failure or the self-sustaining operation, the impedance on the power storage means side is made lower than that of the power generation means, or the impedance on the power generation means side is It turned into high impedance from the power storage unit, or the impedance of the power storage unit side turned into a low impedance from the power generating means, and that the impedance of the power generating means side turn into high impedance from the accumulator unit.

  According to the present invention, any of the following effects can be obtained.

  (1) When the grid power supply is connected, power is supplied to the distribution system from the grid power supply and the distributed power supply, and the power storage means side is made to have a higher impedance than the power generation means side during a power failure of the system power supply or the independent operation of the distributed power supply. The load sharing on the power generation means side can be reduced by switching or switching the power generation means side to a lower impedance than the power storage means.

  (2) It is possible to avoid isolated operation detection by reducing the load sharing on the power generation means side of the distributed power source during a power failure of the system power source or the independent operation of the distributed power source, and continuous power supply at the time of power failure of the system power source. And the continuity and stability of the power supply can be maintained.

Other objects, features, and advantages of the present invention will become clearer with reference to the accompanying drawings and each embodiment.

It is a figure which shows the electric power feeding system which concerns on 1st Embodiment. It is a figure which shows the operation | movement at the time of the grid connection (power recovery from a power failure) of an electric power feeding system. It is a figure which shows the operation | movement at the time of a power failure of an electric power feeding system. It is a figure which shows the function of a control part. It is a figure which shows an example of the hardware of a control part. It is a figure which shows the electric power feeding system which concerns on 2nd Embodiment. It is a figure which shows the operation | movement at the time of the grid connection (power recovery from a power failure) of an electric power feeding system. It is a figure which shows the operation | movement at the time of a power failure of a system power supply. It is a figure which shows the electric power feeding system which concerns on 3rd Embodiment. It is a figure which shows the impedance switching part of the electrical storage system which concerns on 4th Embodiment. It is a figure which shows the impedance switching part of FC system. It is a figure which shows the electric power feeding system which concerns on 5th Embodiment. It is a figure which shows an electric power feeding system. It is a figure which shows an electric power feeding system. It is a figure which shows the function of a control part. It is a flowchart which shows the process sequence of electric power feeding control. It is a figure which shows the electric power feeding system which concerns on other embodiment.

[First Embodiment]

<System configuration>

  FIG. 1 shows a power supply system according to the first embodiment. The configuration shown in FIG. 1 is an example, and the present invention is not limited to such a configuration.

  The power supply system 2 includes a power distribution system 4. A system power supply 6 is connected to the power distribution system 4. The system power supply 6 is, for example, a power supply supplied from an electric power company.

  A power load 8 is connected to the distribution system 4. The electric power load 8 includes an air conditioner (electric air conditioner), an electric toilet seat, an electric washing machine, an electric refrigerator, an electric vacuum cleaner, an IH cooking heater, and the like that generate a sudden current change, an electric light, a television receiver, and the like. Includes those with little current change.

  A distributed power supply 10 is connected to the power distribution system 4. The distributed power source 10 is an example of a distributed power source. The distributed power source 10 includes a power storage system 12 and an FC system (fuel cell cogeneration system) 14. The power storage system 12 is an example of power storage means. The FC system 14 is an example of power generation means.

  The power storage system 12 receives and stores system power from the system power supply 6 during grid connection, and during a power failure of the system power supply 6 or when the distributed power supply 10 operates independently (hereinafter simply referred to as “self-supporting operation”). Power is supplied to the power load 8 and the FC system 14. The power storage system 12 includes a voltage sensor 16, a switch 18, an inverter (INV) 20, a storage battery 22, and an impedance switching unit 24.

  The voltage sensor 16 is connected to the input end of the power distribution system 4 and detects the state of the system power supply 6 at this input end. The voltage sensor 16 is an example of a detection unit that detects the state of the system power supply 6, and detects a state such as power supply to the system power supply 6, power failure, or power recovery from a power failure.

  The switch 18 is an example of a shut-off means for the power distribution system 4. The switch 18 is installed in the power distribution system 4 on the rear stage side of the voltage sensor 16. The switch 18 opens and closes in response to the sensor output of the voltage sensor 16. The switch 18 is closed at the time of grid connection (at the time of power supply to the system power supply 6 or at the time of power recovery), and is opened at the time of a power failure.

  The voltage sensor 16 and the switch 18 can be constituted by a relay solenoid and a normally closed contact, for example. In other words, when the grid is connected, the normally closed contact is closed by energizing the solenoid and the system power supply 6 is fed to the power distribution system 4, and when the system power supply 6 is powered off, the normally closed contact is opened by deenergizing the solenoid and the system power supply 6 is distributed. Disconnect from system 4. At this time, the power supply of the system power supply 6 to the power distribution system 4 is stopped by the disconnection of the system power supply 6. In this case, power supply to the power distribution system 4 shifts to a self-sustained operation by the distributed power supply 10.

  The INV 20 converts the AC input from the system power supply 6 into DC and feeds power to the storage battery 22 during grid connection, and converts the DC output from the storage battery 22 into AC during a power failure. In this embodiment, when the switch 18 is closed, the AC input from the system power supply 6 is input to the INV 20 through the impedance switching unit 24.

  The storage battery 22 is charged by receiving the DC output of the INV 20 during grid connection, and sends the DC output, and outputs the stored power to the INV 20 at the time of a power failure of the system power supply 6 or during a self-sustaining operation. This electricity storage output is converted into alternating current by INV 20 and sent to the distribution system 4 through the impedance switching unit 24.

  The impedance switching unit 24 is an example of a means for increasing the impedance on the power storage system 12 side with respect to the FC system 14 during grid connection. The power storage system is used when the system power supply 6 is out of power or when the distributed power supply 10 is operating independently. This is an example of means for reducing the impedance on the 12 side with respect to the FC system.

  The impedance switching unit 24 includes a first reactor 26-1, a second reactor 26-2, and a switch 28. Each of the reactors 26-1 and 26-2 is an example of an inductor. The reactor 26-1 is an example of a high impedance circuit that increases the impedance of the power storage system 12 side with respect to the FC system 14 during grid connection. Reactor 26-2 is an example of a low impedance circuit that lowers the impedance of power storage system 12 with respect to FC system 14 at the time of a power failure of system power supply 6 or the independent operation of distributed power supply 10.

  The switch 28 includes contacts a and b and is switched by the sensor output of the voltage sensor 16. A reactor 26-1 is connected between the contact a side and the power distribution system 4. A reactor 26-2 is connected between the contact b side and the power distribution system 4. The switch 28 is closed to the contact a side when the system is connected, and is closed to the contact b side when the power supply of the system power supply 6 is interrupted. Therefore, the reactor 26-1 is connected at the time of grid connection, and the reactor 26-2 is connected at the time of a power failure.

  The FC system 14 generates power by supplying power from the system power supply 6 during grid connection, and generates power by supplying power from the power storage system 12 during a power failure or autonomous operation of the system power supply 6. The FC system 14 includes a power generation stack 30, an inverter (INV) 32, a current sensor 34, a control unit 36, and a third reactor 38. The power generation stack 30 receives voltage input from the distribution system 4 via the INV 32 and generates power.

  The INV 32 converts the direct current output into alternating current when the system is connected and when the power supply 6 is out of power, and converts the direct current output of the power generation stack 30 into alternating current during the power outage.

  The current sensor 34 is an example of an AC output monitoring unit of the FC system 14. The sensor output of the current sensor 34 represents the status of current output supplied from the FC system 14 to the power distribution system 4.

  The control unit 36 is an example of a control unit, and is configured by a microcomputer, for example. The control unit 36 receives the sensor outputs of the voltage sensor 16 and the current sensor 34 and performs power generation control. The sensor output of the voltage sensor 16 is used as grid connection information, power failure information, or power recovery information. The sensor output of the current sensor 34 is used for monitoring the AC output. The control unit 36 shifts to an operation at the time of grid connection based on the grid connection information, an operation at the time of power failure based on the power failure information, or an operation at the time of grid connection based on the power recovery information. Further, the control unit 36 responds to a sudden current change appearing in the sensor output of the current sensor 34. For example, when a sudden current is sent from the FC system 14, the control unit 36 generates power of the FC system 14 by an isolated operation detection operation. Stop.

  The reactor 38 is an example of an inductor. The reactor 38 is connected as means for increasing the impedance on the FC system 14 side. The generated power of the FC system 14 is fed from the INV 32 to the distribution system 4 through the reactor 38.

<Operation during grid connection>

  In the power feeding system 2, as shown in FIG. 2, the voltage sensor 16 detects the interconnection state of the system power supply 6, and the switch 18 is closed. As a result, the system power Ps is supplied from the system power supply 6 to the distribution system 4.

During power feeding, the power storage system 12 is charged or discharged. In the case of discharge, the power Pb from the power storage system 12 is output to the power distribution system 4. Further, if the FC system 14 is fed from the system power supply 6 to generate power, and the generated power Pg is output to the distribution system 4 and the power supplied to the power load 8 is Pw1, this supply power Pw1 is
Pw1≈Ps + Pb + Pg (1)
It becomes.

  At this time, the reactor 26-1 is connected to the power storage system 12 side. The impedance on the power storage system 12 side is set to a high impedance ZbH. When the impedance on the FC system 14 side is Zg, the magnitude relationship between the impedances ZbH and Zg is ZbH> Zg.

<Operation at power failure of system power supply 6>

  As shown in FIG. 3, when the voltage sensor 16 detects a power failure of the system power supply 6, the switch 18 is opened. Thereby, the system power source 6 is disconnected from the power distribution system 4, and the distributed power source 10 is switched to the independent operation.

The FC system 14 is supplied with power from the power storage system 12 to generate power, and outputs the generated power Pg to the distribution system 4. Accordingly, if the power supplied from the distribution system 4 to the power load 8 is Pw2, the supplied power Pw2 is Ps = 0.
Pw2≈Pb + Pg (2)
It becomes.

  At this time, the power storage system 12 is switched from the reactor 26-1 to the reactor 26-2. Thereby, the impedance on the power storage system 12 side is switched to the low impedance ZbL. The magnitude relationship between the impedances ZbL and Zg is ZbL <Zg.

  Thus, at the time of a power failure of the system power supply 6 or the autonomous operation of the distributed power supply 10, the impedance Zg on the FC system 14 side is higher than the impedance of the power storage system 12. For this reason, even if an instantaneous large current flows through the power load 8, power is easily supplied from the low-impedance power storage system 12 side, and is not easily supplied from the high-impedance FC system 14 side. For this reason, the voltage drop by the side of FC system 14 can be controlled. Thereby, the independent operation detection of the FC system 14 can be avoided, and continuous power supply from the distributed power supply 10 to the power load 8 can be performed.

<Operation when system power supply 6 is restored>

  As shown in FIG. 2, when the voltage sensor 16 detects the power recovery of the system power supply 6, the switch 18 is closed. Thereby, the disconnection of the system power supply 6 is canceled, and the system shifts to the grid interconnection operation. System power Ps is supplied to the distribution system 4 from the system power supply 6.

  At this time, the switch 28 is closed to the contact a side, and the impedance of the power storage system 12 is switched to the high impedance ZbH. As a result, the above-described power (Pw1≈Ps + Pb + Pg) is supplied to the power load 8.

<Control Function of Control Unit 36>

  FIG. 4 shows the control function of the control unit 36 of the FC system 14. The control unit 36 executes information processing by a computer. This information processing includes a state determination function 40, a power generation output monitoring function 42, a protection control function 44, and the like.

  The state determination function 40 determines the state of the system power supply 6. The state of the system power supply 6 includes grid connection, power failure, and power recovery from power failure. That is, the state determination function 40 is a state determination function for grid connection, power failure, and power recovery from a power failure. Therefore, the state determination function 40 receives the sensor output of the voltage sensor 16 as an example, and determines whether the system power supply 6 is in a connected state, a power failure state, or a state where power is restored from a power failure. This state determination may be made by receiving a sensor output from the voltage sensor 16 as in this embodiment, or may receive state information from the power storage system 12.

  The power generation output monitoring function 42 receives, for example, the sensor output of the current sensor 34 and performs isolated operation detection. When the FC system 14 detects an isolated operation, the FC system 14 sends out a monitoring output for achieving the protection function.

  The protection control function 44 executes the operation of the FC system 14 within a set protection condition range. The FC system 14 performs a protection function such as power generation stop when the power generation output monitoring function 42 detects the above-described isolated operation during grid connection or when power is restored from a power failure.

<Hardware of control unit 36>

  FIG. 5 shows an example of hardware of the control unit 36. The control unit 36 is configured by a computer. The control unit 36 includes, for example, a processor 46, a ROM (Read-Only Memory) 48, an NVM (Non Volatile Memory) 50, a RAM (Random-Access Memory) 52, and an input / output unit (I / O) 54. These functional units such as the processor 46 are connected by a bus 56.

  The processor 46 executes an OS (Operating System) in the ROM 48, executes a firmware program and an application program, and performs information processing and control including the above-described functions. The ROM 48 is an example of a program storage unit, and is configured by a storage medium such as a semiconductor storage element, for example. The ROM 48 stores an OS, a firmware program, and an application program. Various data are stored in the NVM 50, and a database is constructed. The NVM 50 is configured by a nonvolatile memory such as an EEPROM (Electrically Erasable Programmable Read-Only Memory). The NVM 50 stores various control information such as setting information, and the control information includes protection condition information for realizing the above-described protection function. This protection condition information includes, for example, a grid connection protection function (detection condition) data table, an isolated operation detection (passive method) condition data table, an isolated operation detection (active method) condition data table, and the like. The RAM 52 forms a work area for information processing. The I / O 54 is used for setting information input and control output extraction.

<Effect of the first embodiment>

  In the first embodiment, the following effects can be obtained.

  (1) The voltage sensor 16 detects a power failure of the system power supply 6 and generates a sensor output indicating the power failure detection. With this sensor output, the switch 18 is opened and the system power supply 6 is disconnected. At the same time, the distributed power supply 10 shifts to a self-sustained operation. In the distributed power supply 10 that has shifted to the self-sustained operation, the impedance on the power storage system 12 side is switched to the impedance ZbL, and the impedance becomes low. That is, the impedance Zg on the FC system 14 side is higher than the impedance ZbL on the power storage system 12 side. As a result, the current on the FC system 14 side can be suppressed, the power generation stoppage due to the independent operation detection of the FC system 14 can be avoided, the power generation by the FC system 14 of the distributed power supply 10 can be continued, and the generated power of the distributed power supply 10 can be effectively used. Figured.

  (2) During grid connection, the power consumption of the power load 8 can be covered by the grid power of the grid power supply 6 and the output power of the distributed power supply 10 including the power storage system 12 and the FC system 14.

  (3) When the distributed power supply 10 is operated independently even when the power supply of the system power supply 6 is interrupted or the power supply of the system power supply 6 is being supplied, an instantaneous large current does not flow from the FC system 14, and the FC system 14 Effective use of the power of the distributed power source 10 such as the FC system 14 can be achieved while avoiding inconveniences such as operation stoppage due to isolated operation detection.

[Second Embodiment]

<System configuration>

  FIG. 6 shows a power feeding system according to the second embodiment. The configuration shown in FIG. 6 is an example, and the present invention is not limited to such a configuration. In FIG. 6, the same parts as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

  The power storage system 12 of this embodiment includes a voltage sensor 16, a switch 18, an inverter (INV) 20, a storage battery 22, and a reactor 26. In this case, the reactor 26 has a constant impedance. The reactor 26 is connected as means for increasing the impedance on the power storage system 12 side.

  The FC system 14 includes a power generation stack 30, an inverter (INV) 32, a current sensor 34, a control unit 36, and an impedance switching unit 58.

  The impedance switching unit 58 includes a first reactor 38-1, a second reactor 38-2, and a switch 60. Reactor 38-1 is an example of a low impedance circuit that reduces the impedance on the FC system 14 side with respect to power storage system 12 during grid connection. Reactor 38-2 is an example of a high-impedance circuit that increases the impedance on the FC system 14 side with respect to power storage system 12 at the time of power failure of system power supply 6 or autonomous operation of distributed power supply 10.

  The switch 60 includes contacts a and b and is switched by the sensor output of the voltage sensor 16 on the power storage system 12 side. A reactor 38-1 is connected between the contact a side and the power distribution system 4. A reactor 38-2 is connected between the contact b side and the power distribution system 4. The switch 60 is closed to the contact a side during grid connection, and is closed to the contact b side during a power failure of the system power supply 6 or a self-sustaining operation of the distributed power supply 10. Therefore, the reactor 38-1 is connected at the time of grid connection, and the reactor 38-2 is connected at the time of a power failure.

  The power generation stack 30 receives voltage input from the distribution system 4 via the INV 32 and generates power. The INV 32 converts the direct current output of the power generation stack 30 into alternating current at the time of grid connection and at the time of power failure of the system power supply 6.

  The current sensor 34 is an example of an AC output monitoring unit of the FC system 14. The sensor output of the current sensor 34 represents the status of current output supplied from the FC system 14 to the power distribution system 4.

<Operation during grid connection>

  In the power feeding system 2, as shown in FIG. 7, the voltage sensor 16 detects the interconnection state of the system power supply 6, and the switch 18 is closed. As a result, the system power Ps is supplied from the system power supply 6 to the distribution system 4.

  During power feeding, the power storage system 12 is charged or discharged. In the case of discharge, the power Pb from the power storage system 12 is output to the power distribution system 4. Further, if the FC system 14 is fed with power from the system power supply 6 and generates power, and the generated power Pg is output to the distribution system 4 and the power supplied to the power load 8 is Pw1, the supplied power Pw1 is as described above. This is as shown in equation (1).

  At this time, the reactor 38-1 is connected to the FC system 14 side. The impedance on the FC system 14 side is set to a low impedance ZgL. Assuming that the impedance on the power storage system 12 side is Zb, the magnitude relationship between the impedances ZgL and Zb is ZgL <Zb.

<Operation at power failure of system power supply 6>

  As shown in FIG. 8, when the voltage sensor 16 detects a power failure of the system power supply 6, the switch 18 is opened. Thereby, the system power source 6 is disconnected from the power distribution system 4, and the distributed power source 10 is switched to the independent operation.

  The FC system 14 is supplied with power from the power storage system 12 to generate power, and outputs the generated power Pg to the distribution system 4. As a result, if the power supplied from the distribution system 4 to the power load 8 is Pw2, the supplied power Pw2 is as described in the above-described equation (2) because Ps = 0.

  At this time, the FC system 14 is switched from the reactor 38-1 to the reactor 38-2. Thereby, the impedance on the FC system 14 side is switched to the high impedance ZgH. The magnitude relationship between the impedances ZgH and Zb is ZgH> Zb.

  Thus, at the time of a power failure of the system power supply 6 or the autonomous operation of the distributed power supply 10, the impedance ZgH on the FC system 14 side is higher than the impedance Zb of the power storage system 12. For this reason, even if an instantaneous large current flows through the power load 8, power is easily supplied from the low-impedance power storage system 12 side, and is not easily supplied from the high-impedance FC system 14 side. For this reason, the voltage drop by the side of FC system 14 can be controlled. Thereby, the independent operation detection of the FC system 14 can be avoided, and continuous power supply from the distributed power supply 10 to the power load 8 can be performed.

<Operation when system power supply 6 is restored>

  As shown in FIG. 7, when the voltage sensor 16 detects the power recovery of the system power supply 6, the switch 18 is closed. Thereby, the disconnection of the system power supply 6 is canceled, and the system shifts to the grid interconnection operation. System power Ps is supplied to the distribution system 4 from the system power supply 6.

  At this time, the switch 60 is closed to the contact a side, and the impedance of the FC system 14 is switched to the low impedance ZgL. As a result, the above-described power (Pw1≈Ps + Pb + Pg) is supplied to the power load 8.

<Effects of Second Embodiment>

  In the second embodiment, the following effects can be obtained.

  (1) At the time of a power failure of the system power supply 6, the switch 18 is opened by the sensor output of the voltage sensor 16, the system power supply 6 is disconnected, and the distributed power supply 10 shifts to the autonomous operation. In the distributed power supply 10 that has shifted to this self-sustained operation, the impedance on the FC system 14 side is switched to the high impedance ZgH, resulting in a high impedance. That is, the impedance ZgH on the FC system 14 side is higher than the impedance Zb on the power storage system 12 side. Thereby, the electric current by the side of FC system 14 can be controlled, the stop of power generation by the independent operation detection of FC system 14 can be avoided, and the power generation by FC system 14 of distributed power supply 10 can be continued as in the first embodiment, Effective use of the power generated by the distributed power supply 10 is achieved.

  (2) Also in this embodiment, at the time of grid connection, the power consumption of the power load 8 can be covered by the grid power of the grid power supply 6 and the output power of the distributed power supply 10 including the power storage system 12 and the FC system 14. .

  (3) Also in this embodiment, when the distributed power supply 10 is operated independently during a power failure of the system power supply 6 or while the system power supply 6 is supplying power, an instantaneous large current is not supplied from the FC system 14. Thus, it is possible to effectively use the power of the distributed power source 10 such as the FC system 14 while avoiding inconveniences such as the operation stop due to the detection of the independent operation of the FC system 14.

[Third Embodiment]

  FIG. 9 shows a power feeding system according to the third embodiment. 9, the same parts as those in FIGS. 1 and 6 are denoted by the same reference numerals.

  In this embodiment, the power storage system 12 is provided with reactors 26-1 and 26-2 and a switch 28 as in the first embodiment (FIG. 1), and the FC system 14 is in the second embodiment. Similarly to (FIG. 6), reactors 38-1, 38-2 and a switch 60 are provided.

  In such a configuration, the switches 28 and 60 are closed to the contact a side by the sensor output of the voltage sensor 16 at the time of grid connection and power recovery from a power failure. In this case, the reactor 26-1 is connected to the power storage system 12, and the reactor 38-1 is connected to the FC system 14. As a result, the impedance of the power storage system 12 is made higher than that of the FC system 14. That is, in this embodiment, the impedance relationship is ZbH> ZgL.

  At the time of power failure of the system power supply 6, the switches 28 and 60 are closed to the contact b side by the sensor output of the voltage sensor 16. In this case, the reactor 26-2 is connected to the power storage system 12, and the reactor 38-2 is connected to the FC system 14. As a result, the impedance of the power storage system 12 is lower than that of the FC system 14. That is, in this embodiment, the impedance relationship is ZbL <ZgH.

  With such a configuration, an instantaneous large current on the FC system 14 side can be suppressed, and a power generation stoppage due to detection of an independent operation of the FC system 14 can be avoided. As in the first embodiment, the FC system 14 of the distributed power supply 10 can be avoided. Therefore, the power generated by the distributed power source 10 can be effectively used.

[Fourth Embodiment]

  FIG. 10 shows the impedance switching unit 24 on the power storage system 12 side according to the fourth embodiment. 10, the same parts as those in FIG. 1 are denoted by the same reference numerals.

  In the impedance switching unit 24 of the power storage system 12 of the above embodiment, a reactor 26-1 is installed as a high impedance circuit, and a reactor 26-2 is installed as a low impedance circuit. On the other hand, as shown in FIG. 10, a reactor 26-11, 26-12 may be provided as a high impedance circuit, and a capacitor 26-3 may be provided. The reactor 26-11 is connected in series between the INV 20 and the power distribution system 4 via the contacts a1, a2 of the switch 28, and the INV 20 is connected to the power distribution system 4 via the contacts b1, b2 of the switch 28. It is connected. The capacitor 26-3 is connected to the power distribution system 4 in parallel with the INV 20 via the contacts c1 and c2 of the switch 28. That is, the capacitor 26-3 is included in the low impedance circuit. In this case, at the time of grid connection, the contacts a1 and a2 of the switch 28 are closed, and the contacts b1 and b2 and the contacts c1 and c2 are opened. Further, at the time of a power failure or when the distributed power supply 10 is operated independently, the contacts a1 and a2 of the switch 28 are opened, and the contacts b1 and b2 and the contacts c1 and c2 are closed. Thereby, the FC system 14 side can be made high impedance with respect to the electrical storage system 12 at the time of a power failure or the independent operation of the distributed power supply 10. Further, when the power load 8 consumes an instantaneous large current, the instantaneous large current is suppressed by supplementing the current from the capacitor 26-3.

  FIG. 11 shows the impedance switching unit 58 of the FC system 14 according to the fourth embodiment. In FIG. 11, the same parts as those in FIG.

  In the impedance switching unit 58 of the FC system 14 of the above embodiment, a reactor 38-1 is installed as a low impedance circuit, and a reactor 38-2 is installed as a high impedance circuit. On the other hand, as shown in FIG. 11, reactors 38-21 and 38-22 and a capacitor 38-3 may be provided as a high impedance circuit. In this case, the capacitor 38-3 is included in the impedance reduction circuit and is connected in parallel to the INV 32 via the contacts b1 and b2 of the switch 60. The reactors 38-21 and 38-22 are connected in series between the INV 32 and the power distribution system 4 via the contacts b <b> 1 and b <b> 2 of the switch 60. At the time of grid connection, the contacts b1 and b2 and the contacts c1 and c2 of the switch 60 are opened, and the contacts a1 and a2 are closed. At the time of a power failure or when the distributed power supply 10 is operated independently, the contacts a1 and a2 of the switch 60 are opened, and the contacts b1 and b2 and the contacts c1 and c2 are closed. Thereby, the FC system 14 side can be made high impedance with respect to the electrical storage system 12 at the time of a power failure or the independent operation of the distributed power supply 10. In this case, when the power load 8 consumes an instantaneous large current, the instantaneous large current is suppressed by supplementing the current from the capacitor 38-3.

  Even with such a configuration, functions similar to those in the first embodiment or the second embodiment can be obtained, and similar effects can be obtained.

[Fifth Embodiment]

<System configuration>

  FIG. 12, FIG. 13 and FIG. 14 show a power feeding system according to the fifth embodiment. 12, FIG. 13 and FIG. 14, the same parts as those in FIG. 1, FIG. 6, and FIG.

  In this embodiment, the sensor output of the voltage sensor 16 is input to the control unit 36, and the switch 28 or the switch 60 is switched by the control output of the control unit 36. Other configurations are the same as those of the first embodiment, the second embodiment, the third embodiment, or the fourth embodiment.

<Function of Control Unit 36>

  FIG. 15 shows functions provided in the control unit 36. In this embodiment, a switch switching function 62 is included together with the state determination function 40 in addition to the functions described above. As described above, the state determination function 40 receives the sensor output of the voltage sensor 16 as an example, and determines whether the system power supply 6 is in a connected state, a power failure state, or a state where power is restored from a power failure.

  The switch switching function 62 uses the sensor output indicating the power failure detection which is one mode of the state determination of the state determination function 40 as power failure detection information from the closing of the contact a of the switch 28 or the switch 60 to the contact b. Switch to closed. When power is restored from a power failure, the sensor output is switched from the closed state of the contact b of the switches 28 and 60 to the open state as power recovery detection information. This function is realized by information processing of the computer (FIG. 5) described above.

<Power supply control>

  FIG. 16 shows a processing procedure of power supply control by the control unit 36. This processing procedure is an example of the power supply control program or power supply control method of the present invention.

  In this processing procedure, the state of the system power supply 6 is monitored at the time of a power failure or during a grid operation. This state monitoring refers to the sensor output of the voltage sensor 16. The state determination function 40 of the control unit 36 determines whether or not the system power supply 6 is out of power based on the sensor output of the voltage sensor 16. In this case, even if the system power supply 6 is supplying power, if the system power supply 6 is disconnected, a sensor output similar to a power failure can be obtained.

  If there is no power failure (NO in S102), the switch 28 or the switch 60 is closed on the contact a side (S103), and the interconnection operation is performed (S104). State monitoring (S101) is performed in this interconnection operation state. In this case, the impedance on the power storage system 12 side is higher than that on the FC system 14 side.

  If it is a power failure (YES in S102), the switch 28 or switch 60 is closed from the contact a to the contact b (S105), and the distributed power supply 10 is operated independently (S106). State monitoring (S101) is performed in this autonomous operation state. In this case, the impedance on the FC system 14 side is higher than that on the power storage system 12 side. Thereby, the independent operation detection of the FC system 14 can be avoided, the continuous power generation of the FC system 14 can be performed, and the generation output can be used.

[Other Embodiments]

  (1) In the above embodiment, the control unit 36 of the FC system 14 is used for power supply control, but a control unit on the power storage system 12 side may be used. In addition, as shown in FIG. 17, an external control unit 64 may be installed instead of the control unit 36 to realize the function of the control unit 36.

  (2) In the configuration example shown in FIG. 17, a switch 66 is provided at the input end of the distribution system 4 connected to the system power supply 6, and the opening / closing of the switch 66 is controlled by the external control unit 64. In this case, an input operation unit 68 may be connected to the external control unit 64, and the switch 66 may be switched from the closed state to the open state by a self-sustaining operation input from the input operation unit 68.

  In such a configuration, even when the system power supply 6 is in a power supply state, the system power supply 6 can be monitored by monitoring the state of the power load 8 by the external control unit 64 or based on a self-sustained operation instruction from the input operation unit 68 by the user. Can be forcibly disconnected from the distributed power supply 10. Since the operation in this disconnected state is the same as the operation at the time of the power failure described above of the system power supply 6, the description thereof is omitted. Even in such a forced switching to the system power supply 6, during the self-sustained operation, an instantaneously large current of the power load 8 is generated by increasing the impedance of the FC system 14 or decreasing the impedance of the power storage system 12. It is possible to avoid the detection of the single operation of the FC system 14 in the case of flowing, and to continuously generate power and use the generated power effectively.

  (3) In the first embodiment, the reactor 26-2 is provided as a low impedance circuit on the power storage system 12 side and the reactor 38 is provided on the FC system 14 side. However, the reactor 26-2 and the reactor 38 are configured as a direct connection circuit. May be.

  (4) In the second embodiment, the reactor 38-1 is provided as a low impedance circuit on the FC system 14 side and the reactor 26 is provided on the power storage system 12 side. However, the reactor 38-1 and the reactor 26 are configured as a direct connection circuit. May be.

  (5) In the third embodiment, the reactors 26-1 and 38-2 are provided as high impedance circuits, and the other reactors 26-2 and 38-1 are configured as a direct connection circuit. It is good also as a structure which equips the switch 28 and the FC system 14 side with the switch 60, and performs the impedance switching of the said embodiment by switching these.

As described above, the most preferable embodiment of the present invention has been described. The present invention is not limited to the above description. Various modifications and changes can be made by those skilled in the art based on the gist of the invention described in the claims or disclosed in the embodiments for carrying out the invention. It goes without saying that such modifications and changes are included in the scope of the present invention.

The present invention relates to a power feeding system, a power feeding control program, and a power feeding control method. When a power failure occurs in a system power supply, an isolated operation of a stationary power generation device such as an FC system is performed by increasing the impedance of the FC system or lowering the impedance of the power storage system. It is possible to avoid power generation stoppage due to detection, realize continuous power generation, and continuously and effectively use generated power.

2 Power supply system 4 Distribution system 6 System power supply 8 Power load 10 Distributed power supply 12 Storage system 14 FC system 16 Voltage sensor 18 Switch 20 Inverter (INV)
DESCRIPTION OF SYMBOLS 22 Storage battery 24 Impedance switching part 26-1 1st reactor 26-11, 26-12 Reactor 26-2 2nd reactor 26-3 Capacitor 28 Switch 30 Power generation stack 32 Inverter (INV)
34 Current Sensor 36 Control Unit 38 Third Reactor 38-21, 38-22 Reactor 38-3 Capacitor 40 State Judgment Function 42 Power Generation Output Monitoring Function 44 Protection Control Function 46 Processor 48 ROM
50 NVM
52 RAM
54 Input / output unit (I / O)
56 Bus 58 Impedance switching unit 60 Switch 62 Switch switching function 64 External control unit 66 Switch 68 Input operation unit

Claims (6)

Connected to a power distribution system fed from a system power source, and provided with a distributed power source including a power storage means and a power generation means,
During power outage of the system power supply or autonomous operation of the distributed power supply,
The power is supplied from the distributed power to the distribution system to the power storage unit side by Rukoto turn into low impedance from the power generating means side,
Or the power is supplied from the distributed power to the distribution system of the power generating means side by Rukoto turn into high impedance from said storage means,
Or power supply system, characterized in that said power storage unit side turned into a low impedance from the power generating means side, and for feeding said power generating means side by Rukoto turn into high impedance from said storage means from said dispersed power source to the power distribution system. A detecting means for detecting a power failure of the system power supply or the autonomous operation of the distributed power supply;
By the power failure detection or the independent operation detection of the detection means,
Low impedance circuit that the impedance of the power storage unit side turn into a low impedance from the power generating means,
Or high impedance circuit that the impedance of the power generating means side turn into high impedance from said storage means,
Or a high impedance circuit that the impedance of the that the impedance of the power storage unit side turn into a low-impedance than the generator means low impedance circuit and the generator means side turn into high impedance from said storage means,
The power supply system according to claim 1, further comprising: The low impedance circuit is:
An inductor connected in series to the power storage means;
Or a capacitor connected in parallel to the power storage means,
The power feeding system according to claim 2, further comprising: an inductor connected in series to the power storage unit and a capacitor connected in parallel to the power storage unit. The high impedance circuit is:
An inductor connected in series to the power generation means;
Or a capacitor connected in parallel to the power generation means,
Or feed system according to claim 2, characterized in that it comprises a capacitor connected in parallel to the inductor and the power generating means is connected in series with the power generating means. A power supply control program for causing a computer mounted in a power supply system connected to a power distribution system fed from a system power supply and including a distributed power source including a power storage means and a power generation means,
Generate impedance switching information based on detection information of power failure of the system power supply or autonomous operation of the distributed power supply,
According to the impedance switching information,
The impedance of the power storage unit side turned into a low impedance from the power generating means,
Or the impedance on the power generation means side is made higher than that of the power storage means,
Or said electrical storage means side impedance turned into a low impedance from the power generation unit, and the power generating means side power supply control program of the power supply system for the processing that turn into high impedance from said storage means to impedance causes the computer to perform the. A power feeding control method for a power feeding system that is connected to a power distribution system fed from a system power source and includes a distributed power source including a power storage unit and a power generation unit,
Detects power failure of grid power supply or autonomous operation of the distributed power supply,
By the power failure detection or the autonomous operation detection,
The impedance of the power storage unit side turned into a low impedance from the power generating means,
Or the impedance on the power generation means side is made higher than that of the power storage means,
Or power supply control method of the power supply system, wherein the impedance of the power storage unit side turned into a low impedance from the power generating means, and that the impedance of the power generating means side turn into high impedance from the accumulator unit.

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