JP2014168322A - Power supply system, power supply control program, and power supply control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve continuity or stability of power supply to an electric power load in a power supply system comprising a distributed power source including power storage means or power generation means during a power failure in a system power source or self-sustaining operation of the distributed power source.SOLUTION: A power supply system (2) for supplying power to a plurality of electric power loads (8) comprises: a first distribution system (4-1) connecting a first electric power load (general electric power load 8-1) selected from among the plurality of electric power loads to a system power source (6); a second distribution system (4-2) connecting a second electric power load (special electric power load 8-2) selected from among the plurality of electric power loads to the system power source; and a distributed power source (10) connected to the first distribution system and including either power storage means (power storage system 12) or power generation means (FC system 14). In power supply from the system power source, the system power source supplies power to the first distribution system and the second distribution system. During a power failure in the system power source or self-sustaining operation of the distributed power source, power supply to the second distribution system is stopped and power is supplied from the distributed power source to the first distribution system.

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 of a distributed power source of an FC system or a storage battery system linked to a grid power source are indispensable for grid connection. 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 combination with the power failure of the system power supply or when the distributed power supply is operating independently, if the power generation of the FC system stops, the power generated by the FC system cannot be used and the burden on the storage battery increases. There is a problem that the consumption of water becomes remarkable.

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

Therefore, 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 during a power failure of a system power source or when a distributed power source operates independently. is there.

  In order to achieve the above object, a power supply system according to the present invention is a power supply system that supplies power to a plurality of power loads, wherein a first power load selected from the plurality of power loads is connected to a system power source. A power distribution system; a second power distribution system for connecting a second power load selected from the plurality of power loads to the system power supply; and at least one of power storage means or power generation means connected to the first power distribution system. A distributed power source including the power supply, and when the power supply of the system power is supplied, the system power supply is supplied to the first power distribution system and the second power distribution system. During operation, power supply to the second power distribution system is stopped and power is supplied from the distributed power source to the first power distribution system.

  To achieve the above object, a power supply system according to the present invention is a power supply system that supplies power to a plurality of power loads, and a power distribution system that connects a first power load selected from the plurality of power loads to a system power supply; The second power load selected from the plurality of power loads and the power distribution system are installed, and when the power supply of the system power supply is cut off or when the distributed power supply is operated independently, the second power load is applied to the power distribution system. An impedance switching means for switching the impedance on the power load side to a high impedance, and at least one of the power storage means or the power generation means, and the first power at the time of a power failure of the system power supply or the autonomous operation of the distributed power supply And a distributed power source for supplying power to the load and supplying power to the second power load switched to the high impedance.

  In the above power supply system, the power distribution system may include detection means for detecting a power failure of the system power supply or detecting a self-sustained operation of the distributed power supply, and control means for controlling impedance switching of the impedance switching means. .

  In the power feeding system, the impedance switching unit may insert a high impedance circuit between the power distribution system and the second power load at the time of a power failure of the system power supply or when the distributed power supply is operated independently. .

  In order to achieve the above object, a power supply control program according to the present invention is a power supply control program that is executed by a computer mounted on a power supply system including a distributed power source including at least either power storage means or power generation means. Control information is generated during a power failure or during the independent operation of the distributed power source, and the first power load and the second power load selected from a plurality of power loads are between the second power load and the distribution system. The impedance switching means installed in the system is controlled by the control information, and when the system power supply is interrupted or when the distributed power supply is operating independently, the impedance on the second power load side is switched to a high impedance, In the event of a power failure or when the distributed power supply is operating independently, the first power load and the high impedance are switched. Wherein executing the process of feeding the dispersed power supply to the computer 2 of the power load.

  In order to achieve the above object, a power supply control method of the present invention is a power supply control method for supplying power to a plurality of power loads, wherein a first power load selected from the plurality of power loads is transmitted by a first distribution system. A second power load selected from the plurality of power loads is connected to the system power source by a second distribution system, and a distributed power source including at least one of power storage means or power generation means is connected to the system power supply. Connected to one power distribution system, and when power is supplied to the system power supply, power is supplied from the system power supply to the first power distribution system and the second power distribution system. At this time, power supply to the second power distribution system is stopped, and power is supplied to the first power distribution system from the distributed power source.

In order to achieve the above object, a power supply control method according to the present invention is a power supply control method for supplying power to a plurality of power loads, wherein a first power load selected from the plurality of power loads is converted into a system power supply by a distribution system. Connecting a distributed power source including at least one of power storage means or power generation means to the power distribution system, and impedance switching means between the second power load selected from the plurality of power loads and the power distribution system. When the power supply of the system power supply is interrupted or when the distributed power supply is operated independently, the impedance on the second power load side with respect to the power distribution system is switched to a high impedance. At the time of self-sustained operation, the distributed power supply supplies power to the first power load and also supplies power to the second power load switched to the high impedance.

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

  (1) For power loads that instantaneously consume a large current, power is supplied from the system power supply and distributed power supply when the grid power supply is connected. Power can be supplied only with a distributed power source.

  (2) The load on the distributed power supply can be reduced, the detection of isolated operation on the distributed power supply side can be avoided, and continuous power can be supplied to the power load that does not consume a large current instantaneously at the time of power failure of the system power supply. The continuity and stability of power supply can be maintained.

  (3) The power load that instantaneously consumes a large current is supplied with power from the grid power supply and the distributed power supply when the grid power supply is connected. Since the power distribution system connected to the power load that consumes a high impedance reduces the current, it is possible to avoid the stoppage of power generation by the power generation means due to the isolated operation detection of the distributed power supply, and to improve the continuity of power supply to the power load , Stability of power supply is improved.

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 a feed system, and a power failure. It is a figure which shows an example of electric power load. It is a figure which shows the control function of FC system. 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 operation | movement of the electric power feeding system at the time of grid connection (power failure to power recovery). It is a figure which shows operation | movement of the electric power feeding system at the time of a power failure. It is a figure which shows the electric power feeding system which concerns on 3rd Embodiment. It is a figure which shows the control function of FC system. It is a figure which shows an example of the hardware of an external control part. It is a flowchart which shows the process sequence of electric power feeding control. It is a figure which shows the high impedance switching part 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.

  This power supply system 2 is an example of the power supply system of the present invention. The power feeding system 2 includes a first power distribution system 4-1 and a second power distribution system 4-2 as a plurality of power distribution systems. A system power supply 6 is commonly connected to the power distribution systems 4-1 and 4-2. This system power supply 6 is a power supply provided from an electric power company, for example.

  A power load 8 is connected to the distribution systems 4-1 and 4-2. This power load 8 is an example of a plurality of power loads. As an example, the power load 8 includes a general power load 8-1 and a special power load 8-2. The general power load 8-1 is an example of a first power load selected from a plurality of power loads. The special power load 8-2 is an example of a second power load selected from a plurality of power loads.

  By the way, the power load 8 includes those that cause a rapid current change such as an air conditioner, an electric refrigerator, and an electric toilet seat, and those that have a small current change such as an electric light and a television receiver. It is. Therefore, if the load selection condition is whether or not a sudden high current flows during power supply, the general power load 8-1 is one that does not flow a sudden high current during power supply, and the special power load is one that flows a rapid high current. It may be 8-2.

  A general power load 8-1 is connected to the power distribution system 4-1, and a distributed power source 10 is connected to the power distribution system 4-1. The distributed power supply 10 is an example of a distributed power supply. A special power load 8-2 is connected to the power distribution system 4-2. In other words, the general power load 8-1 is supplied with power from the system power supply 6 and the distributed power supply 10 when the system power supply 6 is connected, and is distributed so that independent operation can be performed at the time of a power failure of the system power supply 6 or when the system power supply 6 is disconnected. Power is supplied from the power supply 10. On the other hand, only the system power supply 6 is supplied to the special power load 8-2, and the power supply is stopped when the system power supply 6 fails.

  The distributed power supply 10 includes at least a power storage system 12 or 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 general power load 8-1 and the FC system 14. The power storage system 12 includes a voltage sensor 16, a switch 18, an inverter (INV) 20, and a storage battery 22.

  The voltage sensor 16 is an example of a state detection unit that detects a state of the system power supply 6 such as a power failure or a power recovery from a power failure. This voltage sensor 16 is connected to the input end of the power distribution system 4-1, and at this input end, the occurrence of a power failure of the system power supply 6 or power recovery from the power failure is detected.

  The switch 18 is inserted into the input end side of the power distribution system 4-1 and is an example of a shut-off means for the power distribution system 4-1. The switch 18 receives the sensor output of the voltage sensor 16 and closes when the system is connected, and opens when the system power supply 6 is powered off. The voltage sensor 16 and the switch 18 can be constituted by a relay solenoid and a normally closed contact, for example. That is, 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 4-1. Is disconnected from the distribution system 4-1.

  The INV 20 is connected to the power distribution system 4-1 between the switch 18 and the general power load 8-1. 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.

  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 INV20 and sent to the distribution system 4-1.

  The FC system 14 is connected to the power distribution system 4-1 between the power storage system 12 and the general power load 8-1, and generates power by supplying power from the system power supply 6 during grid connection. At this time, power is generated by power supply from the power storage system 12. The FC system 14 includes a power generation stack 24, an inverter (INV) 26, a current sensor 27, and a control unit 28. The power generation stack 24 receives voltage input from the power distribution system 4-1 via the INV 26 and generates power.

  The INV 26 converts the direct current output of the power generation stack 24 into alternating current at the time of grid connection and at the time of power failure of the system power supply 6. The generated power of the FC system 14 is fed from the INV 26 to the power distribution system 4-1.

  The control unit 28 is an example of a control unit, and is configured by a microcomputer, for example. The control unit 28 performs power generation control by monitoring the AC output from the INV 26 to the power distribution system 4-1 and monitoring the grid connection, power failure, or power recovery. In this embodiment, the grid connection information, the power failure information, or the power recovery information is notified as the monitoring information from the voltage sensor 16 to the control unit 28. The control unit 28 shifts to the operation at the time of grid connection by the grid connection information, the operation at the time of power failure by the power failure information, or the operation at the time of grid connection by the power recovery information. The sensor output of the current sensor 27 is used for monitoring the AC output. In response to a sudden current change, for example, when a sudden current is sent from the FC system 14, the power generation of the FC system 14 is stopped by an isolated operation detection operation.

<Operation during grid connection>

In the power feeding system 2, as shown in FIG. 2A, the voltage sensor 16 detects the interconnection state of the system power supply 6 and closes the switch 18. Thereby, the system power Ps1 is supplied from the system power supply 6 to the power distribution system 4-1, and is supplied to the general power load 8-1. At this time, the power storage system 12 performs charging and discharging, but when discharging, the power Pb from the power storage system 12 is output to the power distribution system 4-1 and supplied to the general power load 8-1. Further, the FC system 14 is supplied with power from the system power supply 6 to generate power, and the generated power Pg is output to the power distribution system 4-1 and supplied to the general power load 8-1. If the power supplied to the general power load 8-1 is Pw1, the supplied power Pw1 is
Pw1≈Ps1 + Pb + Pg (1)
It becomes.

  At the time of this grid connection, the grid power Ps2 is fed from the grid power supply 6 to the distribution system 4-2. Thereby, electric power is supplied from the system power supply 6 to the special power load 8-2.

<Operation at power failure of system power supply 6>

  As shown in FIG. 2B, the voltage sensor 16 detects a power failure of the system power supply 6, and the switch 18 is opened. Thereby, the system power supply 6 is disconnected from the power distribution system 4-1. The power storage system 12 outputs the power Pb to the power distribution system 4-1 and supplies it to the general power load 8-1 and the FC system 14.

The FC system 14 is supplied with power from the power storage system 12 and generates power, and the generated power Pg is output to the distribution system 4-1 and supplied to the general power load 8-1. In this case, if the power supplied to the general power load 8-1 is Pw2, the supplied power Pw2 is Ps1 = 0.
Pw2≈Pb + Pg (2)
It becomes.

  At the time of this power failure of the system power supply 6, the system power supply 6 is disconnected from the power distribution system 4-2. For this reason, the power supply is stopped at the special power load 8-2.

<Operation when system power supply 6 is restored>

  As shown in FIG. 2A, 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. Thereby, the system power Ps1 is supplied from the system power supply 6 to the power distribution system 4-1, and is supplied to the general power load 8-1. As a result, the above-described power Pw1 (≈Ps1 + Pb + Pg) is supplied to the general power load 8-1.

  At the time of power recovery, the system power Ps2 is supplied from the system power supply 6 to the distribution system 4-2. Thereby, the system power Ps2 is fed to the special power load 8-2 through the power distribution system 4-2.

<Power load 8>

  FIG. 3 shows an example of the power load 8. The power load 8 includes a plurality of power loads such as an air conditioner, an electric refrigerator, an electric toilet seat, an electric light, an electric clock, and a television receiver.

  If the load selection condition is whether or not a rapid high current flows during power supply, a general power load 8-1 that does not flow a rapid high current during power supply and a special power load 8-2 that flows a rapid high current Selected. In this case, an electric lamp 8-11, an electric clock 8-12, a television receiver 8-13, and the like are selected as the general power load 8-1. For the special power load 8-2, an air conditioner 8-21, an electric refrigerator 8-22, an electric toilet seat 8-23, or the like is selected.

<Control function of FC system 14>

  FIG. 4 shows the control function of the FC system 14. The control unit 28 of the FC system 14 executes information processing by a computer. This information processing includes a state determination function 30, a power generation output monitoring function 32, a protection control function 34, and the like.

  The state determination function 30 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 30 is a state determination function for grid connection, power failure, and power recovery from a power failure. Therefore, the state determination function 30 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 32 receives, for example, the sensor output of the current sensor 27 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 34 executes the operation of the FC system 14 within the range of the set protection conditions. The FC system 14 performs a protection function such as power generation stop when the power generation output monitoring function 32 detects the above-described isolated operation at the time of grid connection or when power is restored from a power failure.

<Hardware of control unit 28>

  FIG. 5 shows an example of the hardware of the control unit 28. The control unit 28 is configured by a computer. The control unit 28 includes, for example, a processor 40, a ROM (Read-Only Memory) 42, an NVM (Non Volatile Memory) 44, a RAM (Random-Access Memory) 46, and an input / output unit (I / O) 48. These functional units such as the processor 40 are connected by a bus 50.

  The processor 40 executes an OS (Operating System) in the ROM 42, executes a firmware program and an application program, and performs information processing and control including the above-described functions. The ROM 42 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 42 stores an OS, a firmware program, and an application program. Various data are stored in the NVM 44, and a database is constructed. The NVM 44 is configured by a nonvolatile memory such as an EEPROM (Electrically Erasable Programmable Read-Only Memory). The NVM 44 stores various control information such as setting information, and the control information includes protection condition information for realizing the protection function described above. 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 46 forms a work area for information processing. The I / O 48 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) A distribution system that receives power from the system power supply 6 is branched into the distribution systems 4-1 and 4-2 on the upstream side of the distributed power supply 10, and the system power supply 6 and the distributed power supply 10 are fed to the power distribution system 4-1. Only the system power supply 6 is separately fed to the distribution system 4-2. The plurality of power loads 8 are classified into a general power load 8-1 that does not instantaneously consume a large current and a special power load 8-2 that instantaneously consumes a large current. A general power load 8-1 is connected to the power distribution system 4-1, and a special power load 8-2 is connected to the power distribution system 4-2. Due to such system separation of power supply, the special power load 8-2 cannot be used in the event of a power failure of the system power supply 6, but the general power load 8-1 that does not generate an instantaneous large current is distinguished from the special power load 8-2. Thus, power can be supplied from the distributed power supply 10. In such a configuration, the FC system 14 can avoid power generation stoppage due to detection of an isolated operation, and can effectively use generated power by continuing power generation.

  (2) Even when the special power load 8-2 is used for the system power by the system power source 6, the distributed power source including the FC system 14 in the distribution system 4-1 separated from the special power load 8-2 Since power is supplied from 10, the operation can be continued without causing an operation abnormality such as a power generation stop due to the isolated operation detection, and the generated power of the FC system 14 can be used effectively.

  (3) At the time of grid connection, the power consumption of the general power load 8-1 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.

  (4) Since the system power is directly supplied to the special power load 8-2, power can be supplied without being affected by the distributed power source 10.

  (5) At the time of power failure of the system power supply 6, the power supply to the special power load 8-2 is stopped and the special power load 8-2 cannot be used, but the power supply to the general power load 8-1 can be continued, The power supply duration time can be extended.

  (6) When the distributed power source 10 is operated independently even when the system power source 6 is out of power or when the system power source 6 is supplying power, an instantaneous large current is not consumed on the distributed power source 10 side. 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 detection of isolated operation of the system 14.

[Second Embodiment]

<System configuration>

  FIG. 6 shows a power supply 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.

  In the second embodiment, the power distribution system 4-2 is branched from the distributed power supply 10 side of the power distribution system 4-1. A high impedance switching unit 60 is connected to the power distribution system 4-2. The high impedance switching unit 60 is an example of impedance switching means. The special power load 8-2 is supplied with the system power Ps of the system power supply 6, the stored power Pb of the distributed power supply 10, and the generated power Pg via the high impedance switching unit 60.

  High impedance switching unit 60 includes a reactor 62, a switch 64, and a short circuit 66. The reactor 62 is an example of a high-impedance circuit that sets the impedance on the special power load 8-2 side to a high impedance.

  The switch 64 is switched by the sensor output of the voltage sensor 16. As an example, the switch 64 includes a contact a and a contact b. A short circuit 66 is connected to the contact a side, and a reactor 62 is connected to the contact b side.

<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. At this time, the switch 64 is closed to the contact a side. That is, the high impedance switching unit 60 is switched to the short circuit 66 to be in a short circuit state, and the reactor 62 is disconnected from the high impedance switching unit 60.

  Thereby, the system power Ps from the system power supply 6 is supplied from the distribution system 4-1 to the general power load 8-1 and also supplied to the distribution system 4-2 branched from the distribution system 4-1.

At this time, the power storage system 12 performs charging and discharging, but when discharging, the power Pb from the power storage system 12 is output to the distribution systems 4-1 and 4-2, and the general power load 8-1 and the special power load 8-2. The FC system 14 is supplied with power from the system power supply 6 and generates power, and the generated power Pg is output to the distribution systems 4-1 and 4-2 and supplied to the general power load 8-1 and the special power load 8-2. The power supplied to the general power load 8-1 and the special power load 8-2 is Pw21, the power supplied to the general power load 8-1 is Pw211, and the power supplied to the special power load 8-2 is Pw212. For example, the supplied power Pw21 is
Pw21 = Pw211 + Pw212≈Ps + Pb + Pg (1)
It becomes.

<Operation at power failure of system power supply 6>

  As shown in FIG. 8, the voltage sensor 16 detects a power failure of the system power supply 6, and the switch 18 is opened. As a result, the system power supply 6 is disconnected from the distribution systems 4-1 and 4-2. At this time, the switch 64 receiving the sensor output of the voltage sensor 16 is switched from the contact a side to the contact b side. In the power distribution system 4-2, the reactor 62 is connected in series to the special power load 8-2 and the impedance is increased.

  The power storage system 12 outputs power Pb to the power distribution systems 4-1 and 4-2, and includes the general power load 8-1, the FC system 14, and the special power load 8-2 having a high impedance. 2 is supplied.

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 systems 4-1 and 4-2. In this case, if the power supplied to the general power load 8-1 and the special power load 8-2 is Pw22, the supplied power Pw22 is supplied to the general power load 8-1 because Ps = 0. If the power to be supplied is Pw221 and the power supplied to the special power load 8-2 is Pw222, the supplied power Pw22 is
Pw22 = Pw221 + Pw222≈Pb + Pg (2)
It becomes.

  In this case, the power distribution system 4-2 including the special power load 8-2 has a high impedance due to the series connection of the reactors 62. As a result, the supply power Pw22 is fed to the distribution system 4-2 including the special power load 8-2 having a high impedance, and the current consumption from the distributed power supply 10 to the special power load 8-2 is reduced.

<Operation when system power supply 6 is restored>

  When the voltage sensor 16 detects the power recovery of the system power supply 6, as shown in FIG. 7, the switch 18 is closed, the system power supply 6 is disconnected, and the system connection operation is started. At this time, the switch 64 returns from the contact b to the contact a. The short circuit 66 is selected and the reactor 62 is disconnected.

  Thereby, the system power Ps is supplied from the system power supply 6 to the distribution systems 4-1 and 4-2 and supplied to the general power load 8-1 and the special power load 8-2. As a result, the above-described power Pw21 (≈Ps + Pb + Pg) is supplied to the general power load 8-1 and the special power load 8-2.

  At the time of this grid connection, it is possible to avoid current concentration on the distributed power source 10 by the special power load 8-2 that generates a large current instantaneously.

<Effects of Second Embodiment>

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

  (1) According to this embodiment, unlike the first embodiment, when the system power supply 6 is connected to the grid, the general power load 8-1 and the special power load 8 are generated by the power of the system power supply 6 and the distributed power supply 10. -2 can be powered. At the time of grid connection, the power consumption of the power load 8 can be covered by the power of the grid power supply 6, the power storage system 12, and the FC system 14.

  (2) When the voltage sensor 16 detects a power failure of the system power supply 6, the reactor 62 of the high impedance switching unit 60 is connected in series to the special power load 8-2 side, and the special power load 8-2 side becomes high impedance. be able to. For this reason, in this embodiment, the power of the distributed power supply 10 can be supplied to the general power load 8-1 and the special power load 8-2 side having a high impedance. In this embodiment, since the distribution system 4-2 of the special power load 8-2 is increased in impedance, current distribution can be reduced by increasing the impedance on the special power load 8-2 side when a power failure occurs. . For this reason, the special power load 8-2 can be used while suppressing an instantaneous large current, and the FC system 14 can continue to generate power while avoiding the detection of isolated operation. Can be used. In addition, the special power load 8-2 can be used by supplying power from the distributed power supply 10 while suppressing instantaneous large current consumption, and a highly convenient power supply system 2 can be constructed.

  (3) Even when the special power load 8-2 is used, the FC system 14 can avoid the isolated operation detection of the distributed power supply 10 and can continue to operate, and the stored power and the generated power can be effectively used.

  (4) Even when the grid connection is shifted to the power failure, the use of the special power load 8-2 can be continued only by connecting the reactor 62 of the switch 64. It is not necessary to switch the power supply path for the special power load 8-2.

  (5) At the time of a power failure or when the distributed power supply 10 is operating independently, the connection of the reactor 62 can suppress a momentary large current from flowing through the distribution system 4-2 on the special power load 8-2 side. The power burden on the distributed power supply 10 side can be reduced.

[Third Embodiment]

<System configuration>

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

  In the power supply system 2 of this embodiment, a switch 68 and an external control unit 70 are provided in the power supply system 2 shown in FIG. The switch 68 is an example of a switching unit for switching the distributed power supply 10 to a self-sustained operation when the system is connected, that is, when the system power supply 6 is not out of power. This switch 68 is installed in the front | former stage side of the voltage sensor 16, and is installed between the system power supply 6 and the input terminal of the power distribution system 4-1. The switch 68 can be opened and closed by the external control unit 70.

  The external control unit 70 is an example of a control unit that performs opening / closing control of the switch 68 and the switch 64. The external control unit 70 is configured by a computer, for example, and receives the sensor output of the voltage sensor 16. In this case, when the switch 68 is closed, the voltage sensor 16 functions as a state detection unit, a power failure detection unit, or a power recovery detection unit of the system power supply 6. On the other hand, when the switch 68 is forcibly opened during grid connection, the disconnection of the grid power supply 6 is detected by the voltage sensor 16. That is, the voltage sensor 16 generates a sensor output indicating the shift of the distributed power supply 10 to the independent operation. Therefore, in this embodiment, the voltage sensor 16 functions as a self-sustained operation detecting means, and in this case, the sensor output indicates the self-sustained operation information.

<Function of Power Supply System 2 Including External Control Unit 70>

  FIG. 10 shows functions of the power feeding system 2 including the external control unit 70. While the control unit 28 executes the above-described function (FIG. 4), in the configuration including the external control unit 70, the operation switching function 72, the state determination function 74, and the switch switching function 76 are provided on the external control unit 70 side. Realized.

  The operation switching function 72 switches from the grid-connected operation to the self-sustained operation of the distributed power source 10 according to the needs of the user and the load state of the power load 8, and from the self-supporting operation to the grid-connected operation.

  When the operation switching function 72 switches the operation, the state determination function 74 determines whether the system power supply 6 has been disconnected from the distributed power supply 10 based on, for example, the independent operation detection information including the sensor output of the voltage sensor 16 or the system from the disconnected state. Judgment is made on the status such as switching to interconnection.

  The switch switching function 76 switches the switch 64 of the high-impedance switching unit 60 from the state in the grid connection to the connection of the reactor 62 during the independent operation. That is, in this embodiment, the contact point a is switched to the contact point b. When power is restored from the self-sustained operation to the system power supply 6, the system is switched to the system connection state.

<Hardware of External Control Unit 70>

  FIG. 11 shows an example of hardware of the external control unit 70. The external control unit 70 is configured by a computer. The external control unit 70 includes, for example, a processor 78, a ROM 80, an NVM 82, a RAM 84, and an input / output unit (I / O) 86. These functional units such as the processor 78 are connected by a bus 88.

  Similarly to the processor 40 (FIG. 5) described above, the processor 78 executes the OS in the ROM 80, executes a firmware program and an application program, and performs information processing and control including the above-described functions. The ROM 80 is an example of a program storage unit, and is composed of a storage medium such as a semiconductor storage element, for example. The ROM 80 stores an OS, a firmware program, and an application program. Various data are stored in the NVM 82, and a database is constructed. The NVM 82 is constituted by a nonvolatile memory such as an EEPROM, for example. The NVM 82 stores various control information such as setting information. The RAM 84 forms a work area for information processing.

  The I / O 86 is used for setting information input and control output extraction. The I / O 86 is connected to an operation switching operation unit 90, a drive unit 92 of the switch 68, a drive unit 94 of the switch 64, and the like.

  The operation switching operation unit 90 is installed on, for example, an operation panel, and is used for an input operation of a self-sustained operation command for the distributed power source 10 or its release command. The drive unit 92 of the switch 68 opens and closes the switch 68 by a control output from the external control unit 70. The drive unit 94 of the switch 64 performs contact switching of the contact a → contact b and the contact b → contact a of the switch 64 by a control output from the external control unit 70. In the case where the switch 68 and the switch 64 are configured by, for example, relay contacts, the drive units 92 and 94 are solenoids for opening and closing the contacts.

  According to such a configuration, when an independent operation is instructed based on the operation of the operation switching operation unit 90 during grid connection, the external control unit 70 is switched to the independent operation mode. In this case, the switch 68 is opened. Then, the switch 64 is closed to the contact b side. Thereby, the independent operation of the distributed power supply 10 is started. Since this self-sustained operation is described in the second embodiment, the description thereof is omitted.

  In addition, when the self-sustained operation is instructed based on the operation of the operation switching operation unit 90 during the self-sustained operation, the external control unit 70 is switched to the interconnection operation mode. In this case, the switch 68 is closed and the switch 64 is closed to the contact a side. As a result, the self-sustained operation is canceled and the system shifts to the grid interconnection operation. Since this interconnection operation is described in the second embodiment, its description is omitted.

<Processing procedure>

  FIG. 12 shows an example of the processing procedure of the autonomous operation control. This processing procedure is an example of the power supply control program or power supply control method of the present invention.

  This processing procedure is executed at the time of grid connection, for example. In this processing procedure, the state of the system power supply 6 is monitored (S101). In this state monitoring, it is determined whether or not the state of the system power supply 6 is in operation and the power feeding system 2 is in the interconnected operation (S102). If the system is not connected (NO in S102), the state monitoring is continued.

  If the system is in an interconnected operation (YES in S102), operation switching monitoring is performed (S103). In this operation switching monitoring, it is determined whether or not the operation is independent (S104). Whether or not this operation is independent may be determined based on operation switching instruction information for turning ON / OFF the switch 68.

  If it is not a self-sustained operation (NO in S104), state monitoring (S101) is continued. If it is a self-sustained operation (YES in S104), it shifts to a self-sustained operation mode and determines the sensor output of the voltage sensor 16. The sensor output of the voltage sensor 16 is independent operation control information. It is determined whether the sensor output of the voltage sensor 16 is 0 [V] (S105). If the sensor output of the voltage sensor 16 is not 0 [V] (NO in S105), the process of S105 is awaited.

  If the sensor output of the voltage sensor 16 is 0 [V] (YES in S105), the operation shifts to the independent operation mode, the contact b side of the switch 64 is closed, the reactor 62 is connected to the power distribution system 4-2, and the autonomous operation is performed. (S106).

  During this autonomous operation, state monitoring is performed (S107), and it is determined whether the autonomous operation is canceled (S108). If the autonomous operation is not canceled (NO in S108), the autonomous operation is continued (S106).

  If the self-sustained operation is canceled (YES in S108), the self-sustained operation is canceled and the operation mode is shifted to the interconnection operation mode (S109), and the process returns to S101.

  In this embodiment, the case where the distributed power supply 10 is operated autonomously during the interconnection operation is shown, but the same can be done when the distributed power supply 10 starts the independent operation after the operation is stopped.

<Effect of the third embodiment>

  (1) As described above, in the autonomous operation control, control information is generated during the autonomous operation of the distributed power source 10 separated from the system power source 6. During the independent operation, the reactor 62 can be connected to the power distribution system 4-2 to switch the impedance on the special power load 8-2 side to a high impedance so that power can be supplied from the distributed power source 10.

  (2) According to the third embodiment, as in the first or second embodiment, the continuity of power generation of the FC system 14 is enhanced, and the generated power for the power load 8 is effectively used. Can do.

[Other Embodiments]

  (1) In the third embodiment, the control unit 28 and the external control unit 70 are used together. However, the control function of the external control unit 70 may be realized by the control unit 28. May be realized by the external control unit 70.

  (2) In the above embodiment, the FC system 14 is exemplified as the stationary power generation device, but a solar power generation system or an engine power generation system may be used.

  (3) In the second embodiment, the switch 64 is opened and closed by the sensor output of the voltage sensor 16, but the switch 64 may be opened and closed by the external control unit 70 as in the third embodiment. Alternatively, the control unit 28 may receive the sensor output of the voltage sensor 16 to switch the switch 64.

  (4) In the second embodiment, the switch 64 selects either the reactor 62 or the short circuit 66. However, as shown in FIG. 13, the reactor 62 is connected to the short circuit 66 via the switch 64. It is good also as a structure to connect. With such a configuration, the switch 64 is opened and closed by the sensor output of the voltage sensor 16. When power is supplied to the system power supply 6, the switch 64 is closed and the reactor 62 is short-circuited by the short circuit 66. At the time of power failure of the system power supply 6, the switch 64 is opened, and the reactor 62 is connected in series with the special power load 8-2. Thereby, the special electric power load 8-2 can be made high impedance by the serial connection of the reactor 62 at the time of a power failure like the said embodiment, ie, the self-sustained operation of the distributed power supply 10, by the serial connection of the reactor 62.

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, which realizes continuous power generation by avoiding power generation stoppage due to isolated operation detection of stationary power generation equipment such as an FC system at the time of a power failure of a system power supply. In addition, continuous use and effective use of generated power can be achieved.

2 Power supply system 4-1, 4-2 Distribution system 6 System power supply 8 Power load 8-1 General power load 8-1 Special power load 10 Distributed power supply 12 Storage system 14 FC system 16 Voltage sensor 18 Switch 20 Inverter 22 Storage battery 24 Power generation stack 26 Inverter 28 Control unit 30 State determination function 32 Power generation output monitoring function 34 Protection control function 40 Processor 42 ROM
44 NVM
46 RAM
48 I / O unit 50 Bus 60 High impedance switching unit 62 Reactor 64 Switch 66 Short circuit 68 Switch 70 External control unit 72 Operation switching function 74 State judgment function 76 Switch switching function 78 Processor 80 ROM
82 NVM
84 RAM
86 Input / output unit (I / O)
88 Bus 90 Operation switching operation unit 92, 94 Drive unit

Claims (7)

A power supply system that supplies power to a plurality of power loads,
A first power distribution system for connecting a first power load selected from the plurality of power loads to a system power supply;
A second power distribution system for connecting a second power load selected from the plurality of power loads to the system power supply;
A distributed power source connected to the first power distribution system and including at least one of power storage means or power generation means;
And supplying the system power supply to the first power distribution system and the second power distribution system at the time of power supply to the system power supply. A power supply system characterized by stopping power supply to the power distribution system and supplying power from the distributed power source to the first power distribution system. A power supply system that supplies power to a plurality of power loads,
A distribution system for connecting a first power load selected from the plurality of power loads to a system power supply;
The second power is installed between the second power load selected from the plurality of power loads and the distribution system, and the second power to the distribution system at the time of a power failure of the system power supply or the independent operation of the distributed power supply Impedance switching means for switching the impedance on the load side to high impedance;
The power supply means includes at least one of the power storage means and the power generation means, and supplies power to the first power load during a power failure of the system power supply or during a self-sustained operation of the distributed power supply and is switched to the high impedance. A distributed power source for supplying power to two power loads;
A power supply system comprising: Detecting means for detecting a power failure of the system power supply in the distribution system, or detecting self-sustained operation of the distributed power supply;
Control means for controlling impedance switching of the impedance switching means;
The power feeding system according to claim 2, further comprising:   The impedance switching means inserts a high impedance circuit between the power distribution system and the second power load at the time of a power failure of the system power supply or when the distributed power supply is operated independently. Or the electric power feeding system of Claim 3. A power supply control program to be executed by a computer mounted on a power supply system including a distributed power source including at least one of power storage means or power generation means,
Generate control information at the time of power failure of the system power supply or when the distributed power supply is operated independently,
Of the first power load and the second power load selected from the plurality of power loads, the impedance switching means installed between the second power load and the distribution system is controlled by the control information, During a power failure of the system power supply or when the distributed power supply is operating independently, the impedance on the second power load side is switched to a high impedance,
Causes the computer to execute processing for supplying power from the distributed power source to the first power load and the second power load switched to the high impedance at the time of a power failure of the system power source or when the distributed power source is operated independently. Power supply control program for A power supply control method for supplying power to a plurality of power loads,
Connecting a first power load selected from the plurality of power loads to a system power supply by a first distribution system;
A second power load selected from the plurality of power loads is connected to the system power supply by a second distribution system;
Connecting a distributed power source including at least either power storage means or power generation means to the first power distribution system;
When supplying power to the system power supply, power is supplied from the system power supply to the first power distribution system and the second power distribution system,
A power supply control method characterized by stopping power supply to the second power distribution system and supplying power to the first power distribution system from the distributed power supply during a power failure of the system power supply or during independent operation of the distributed power supply . A power supply control method for supplying power to a plurality of power loads,
Connecting a first power load selected from the plurality of power loads to a system power supply by a distribution system;
Connecting a distributed power source including at least either power storage means or power generation means to the power distribution system;
An impedance switching means is installed between the second power load selected from the plurality of power loads and the distribution system,
At the time of a power failure of the system power supply or when the distributed power supply is operated independently, the impedance on the second power load side for the distribution system is switched to a high impedance,
In the event of a power failure of the system power supply or in the independent operation of the distributed power supply, the distributed power supply supplies power to the first power load and also supplies the second power load switched to the high impedance. A power supply control method.

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