JP2013243794A - Power supply system and power supply method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply system and a power supply method capable of preventing deterioration of function and performance of a storage battery unit.SOLUTION: The power supply system includes: a home fuel cell system (power generator) 10 that generates the power to supply the same to a power load; a storage battery unit 20 that supplies the power to a power load 40; a power meter 70 that measures the power supplied from the storage battery unit 20 to the power load 40; and a controller 60. The controller 60 controls the home fuel cell system 10 and the storage battery unit 20 so that the power measured by the power meter 70 is a predetermined power of a value greater than zero while the power load 40 consumes the power.

Description

  The present invention relates to a power supply system and a power supply method including a distributed power source that is linked to a commercial power system, and in particular, when power supply from a commercial power system is stopped due to a power failure or the like, a power generation device and a storage battery device are provided. The present invention relates to a power supply system and a power supply method that perform self-sustaining operation.

  In recent years, a distributed power source has been arranged at the location of a consumer (electric power consumer), and the power from the distributed power source and the power from the commercial power system (commercial power source) of the electric power company are combined. Distributed power supply systems that cover the power consumed by power loads are attracting attention.

  In a distributed power system, in the event of a power outage due to a disaster or a plan, power can be supplied to an electric load by performing a self-sustained operation using a distributed power source that is linked to a commercial power system. Examples of the distributed power source include a power generation device such as a fuel cell system (fuel cell), a solar cell system (solar cell) or a wind power generation system, or a storage battery system (storage battery).

  As this type of conventional technology, for example, Patent Document 1 discloses an emergency power supply system that links a commercial power system and a fuel cell system and supplies power from the fuel cell system to a load in the event of a power failure. .

  An example of a conventional distributed power supply system will be described with reference to FIG. FIG. 13 is a block diagram showing a configuration of a conventional distributed power supply system that can perform private power generation using a household fuel cell system and a storage battery device.

  As illustrated in FIG. 13, the distributed power supply system 100 includes a household fuel cell system 110, a storage battery device 120, a commercial power system 130, a power load 140, and a distribution board 150.

  The home fuel cell system 110 includes a fuel cell main body 111 that generates direct-current power from a fuel gas mainly composed of hydrogen and oxygen, and a grid-connected inverter 112 that converts the direct-current power generated by the fuel cell main body 111 into alternating current. It has.

  The storage battery device 120 includes a storage battery 121 that outputs DC power, and a grid-connected inverter 122 that converts the DC power output from the storage battery 121 into AC power.

  The commercial power system 130 is a system that supplies AC power to a consumer from an electric power company, and predetermined AC power is supplied from the commercial power system 130 to the consumer.

  The power load 140 is a load device that consumes power at the consumer, and is, for example, an electrical product.

  The distribution board 150 serves to select AC power from the household fuel cell system 110, the storage battery device 120, and the commercial power system 130 as desired, and supply the power load 140 to the switch 151, the switch 152, and the switch 152. And a circuit breaker 153 and a circuit breaker 154. The output side of the grid interconnection inverter 112 of the home fuel cell system 110 is connected to the distribution board 150 by a switch 151. The output side of the grid interconnection inverter 122 of the storage battery device 120 is connected to the distribution board 150 by a switch 152. The commercial power system 130 is connected to the distribution board 150 by a circuit breaker 153. The customer's power load 140 is connected to the distribution board 150 by a circuit breaker 154.

  In such a distributed power supply system 100, when power is supplied from the commercial power system 130 (in the normal case), the switch 151, the circuit breaker 153, and the circuit breaker 154 are closed in the distribution board 150. Thus, the power load 140 of the consumer is supplied with the power of the commercial power system 130 and the power of the household fuel cell system 110.

  At this time, when the power consumed by the power load 140 is smaller than the power generation capacity (maximum power generation amount) of the home fuel cell system 110, the power generated by the home fuel cell system 110 is consumed by the power load 140. Following power. In this case, since the electric power consumed by the electric power load 140 may change suddenly depending on the usage state of the electric power load 140 of the consumer, in the domestic fuel cell system 110, the fuel cell main body 111 has the maximum capacity (maximum power generation amount). The surplus power that has been operated and cannot be consumed by the power load 140 is consumed by a surplus power consumption load (such as a heater) provided in the home fuel cell system 110. Thereby, even if the power consumed by the power load 140 changes suddenly, the power supplied from the household fuel cell system 110 to the power load 140 can follow the power consumed by the power load 140.

  Further, when the power consumed by the power load 140 is larger than the power generation capacity of the household fuel cell system 110, power is supplied from the commercial power system 130 to the power load 140 to follow fluctuations in the power consumption of the power load 140. I am letting.

  On the other hand, when the power supply from the commercial power system 130 is stopped due to a power failure or the like, first, the switch 151 is opened to temporarily stop the power supply from the home fuel cell system 110 and the circuit breaker 153 is opened. The distribution board 150 is disconnected from the commercial power system 130. Then, the switch 151, the switch 152, and the circuit breaker 154 are closed, and the household fuel cell system 110 and the storage battery device 120 are started. Thereby, even if the power supply from the commercial power system 130 is stopped due to a power failure, the home fuel cell system 110 and the storage battery device 120 can supply power to the power load 140, so that the self-sustaining operation can be performed. It can be performed.

  At this time, if the home fuel cell system 110 can generate more power than the power consumed by the power load 140, the power supply from the storage battery device 120 is stopped and the home fuel cell system 10 transfers to the power load 140. Is made to follow the power consumption of the power load 140. In this case, in order to follow the sudden change in the power consumption of the power load 140, the fuel cell main body 111 always generates more power than the power consumed by the power load 140 (for example, power generation with the maximum power generation amount). The surplus power that could not be consumed by the load 140 is consumed by the surplus power consuming load provided in the home fuel cell system 110. Thereby, even if the power consumed by the power load 140 changes suddenly, the power supplied from the household fuel cell system 110 to the power load 140 can follow the power consumption of the power load 140.

  In addition, when the power supply from the commercial power system 130 is stopped, if the power consumed by the power load 140 is larger than the power generation capacity of the household fuel cell system 110, the storage battery device 120 is activated to start the storage battery device. Power is also supplied from 120 to the power load 140 to follow fluctuations in power consumption of the power load 140.

JP 2007-228727 A

  However, in a conventional power supply system including a power generation device and a storage battery device such as a household fuel cell system, there is a problem that the power supply possible time of the storage battery device is shortened or the function of the storage battery device is lowered.

  This invention solves the said subject, and provides the electric power supply system, electric power supply method, etc. which can suppress that the electric power supply time of a storage battery apparatus becomes short or the function of a storage battery apparatus falls. Objective.

  In order to solve the above problems, an aspect of a power supply system according to the present invention includes a power generation device that supplies generated power to a power load, a storage battery device that supplies power to the power load, and the storage battery device to A power meter for measuring power supplied to the power load; and a controller, wherein the controller measures power measured by the power meter during a period when the power load is consuming power. The power generator is controlled so as to have a predetermined electric power with a value larger than zero.

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that the electric power supply possible time of a storage battery apparatus becomes short, or the function of a storage battery apparatus falls.

It is a block diagram which shows the structure of the electric power supply system which concerns on Embodiment 1 of this invention. It is a flowchart for demonstrating the operation | movement at the time of a power failure in the electric power supply system which concerns on Embodiment 1 of this invention. It is a figure which shows transition of the electric power during the power failure period in the electric power supply system which concerns on Embodiment 1 of this invention. It is a figure which shows transition of the electric power during the power failure period in the electric power supply system which concerns on the modification of Embodiment 1 of this invention. It is a figure which shows transition of the electric power during the power failure period in the electric power supply system which concerns on the other modification of Embodiment 1 of this invention. It is a block diagram which shows the structure of the electric power supply system which concerns on Embodiment 2 of this invention. It is a flowchart for demonstrating the operation | movement at the time of a power failure in the electric power supply system which concerns on Embodiment 2 of this invention. It is a figure which shows transition of the electric power during the power failure period in the electric power supply system which concerns on Embodiment 2 of this invention. It is a flowchart which shows the method of switching the storage battery apparatus which supplies predetermined | prescribed electric power to electric power load in the electric power supply system which concerns on Embodiment 2 of this invention. It is a figure which shows transition of the electric power during the power failure period in the electric power supply system which concerns on the modification of Embodiment 2 of this invention. It is a flowchart which shows the method of switching the storage battery apparatus which supplies predetermined | prescribed electric power to an electric power load in the electric power supply system which concerns on the modification of Embodiment 2 of this invention. It is a block diagram which shows the structure of the electric power supply system which concerns on Embodiment 3 of this invention. It is a block diagram which shows the structure of the conventional distributed power supply system.

(Knowledge that became the basis of the present invention)
In the conventional power supply system as shown in FIG. 13, when self-sustaining operation is performed when power supply from the commercial power system is stopped due to a power failure or the like, the power load is supplied with power from the power generation device or the storage battery device. Become. In this case, the storage battery device is used as an auxiliary power source of the power generation device. When the power load is smaller than the power generation capacity of the power generation device (home fuel cell system), the storage battery device is stopped and power is supplied from only the power generation device to the power load. Supply. On the other hand, when the power consumption of the power load increases and the power consumption exceeds the power generation capacity of the power generation device, the storage battery device is activated and power is also supplied from the storage battery device to the power load.

  However, when the storage battery device is used in this way, the storage battery device is frequently started and stopped according to the usage state of the power load. For this reason, in the conventional power supply system, the electric power for starting up the storage battery device is consumed, and the amount of charge (remaining capacity) of the storage battery is reduced and the operation time of the storage battery device (power supply) There is a problem that the possible time is shortened.

  In addition, when the storage battery device is frequently started and stopped, charging / discharging of the storage battery is frequently repeated, so that the function of the storage battery device (storage battery) is deteriorated in a short period of time.

  Furthermore, when the power consumed by the power load exceeds the power generation capacity of the power generation device, the output of the storage battery device is tracked according to the power consumption of the power load, but in this case, the power consumption of the power load When the battery suddenly increases, it is necessary to discharge the storage battery rapidly, so that there is a problem that the function of the storage battery device (storage battery) deteriorates in a short period of time.

  The inventors of the present invention have found that the above problems occur with respect to the conventional power supply system. This invention is made | formed based on such knowledge, and it aims at providing the electric power supply system which can suppress the fall of the function and performance of a storage battery apparatus, an electric power supply method, etc.

  In order to achieve this object, an aspect of a power supply system according to the present invention includes: a power generation device that supplies generated power to a power load; a storage battery device that supplies power to the power load; and A power meter for measuring power supplied to the power load; and a controller, wherein the controller measures power measured by the power meter during a period when the power load is consuming power. The power generation device and the storage battery device are controlled so as to have a predetermined power with a value larger than zero.

  According to this aspect, during the period when the power load is consuming the power, the power measured by the power meter is controlled to be the predetermined power, and the output power of the storage battery device is the predetermined power. Yes. That is, the storage battery device continues to supply predetermined power during the period when the power load is consuming power.

  Thereby, since the frequency | count that a storage battery apparatus starts and stops can be reduced, the power consumption accompanying the start of a storage battery apparatus can be reduced. Therefore, it is possible to suppress a reduction in the operable time of the storage battery device.

  Further, the number of times of starting and stopping the storage battery device is reduced, so that the number of repeated charging and discharging of the storage battery can also be reduced. Thereby, it can suppress that the function of a storage battery apparatus falls in a short period with a charging / discharging cycle. Moreover, since it can suppress that the liquid leakage of the storage battery of a storage battery apparatus generate | occur | produces or the output voltage of a storage battery apparatus falls, the reliability of a storage battery apparatus improves.

  Furthermore, the rapid discharge of a storage battery can be suppressed by making output power of a storage battery apparatus into predetermined power. Thereby, it can suppress that the function of a storage battery falls for a short period.

  Furthermore, although it is difficult for the storage battery device to output suddenly high power from a state where the output power is zero (off state), according to this aspect, the storage battery device supplies predetermined power greater than zero. Since it continues, even if it becomes necessary to output high electric power suddenly, it can respond easily.

  Further, in one aspect of the power supply system according to the present invention, the predetermined power may be a predetermined set value or more.

  According to this aspect, since the predetermined power continuously output from the storage battery device is set to a predetermined set value or more, the minimum power to be supplied to the power load can be continuously supplied from the storage battery device. . Thereby, it can continue supplying electric power from a storage battery apparatus with respect to the electric power load required at the time of a power failure.

  Moreover, the aspect of the power supply system according to the present invention may be configured such that the controller determines the predetermined set value according to the amount of charging power of the storage battery device.

  According to this aspect, since the predetermined set value is determined according to the amount of charging power of the storage battery device, the operable time of the storage battery device determined by the amount of charging power (remaining capacity) can be adjusted. For example, by setting the predetermined set value small when the amount of charging power of the storage battery is decreasing, the dischargeable period of the storage battery can be lengthened and the storage battery can be made to last longer. Thereby, the driving | operation possible time of a storage battery apparatus can be lengthened.

  Furthermore, in one aspect of the power supply system according to the present invention, the controller may determine the predetermined set value when starting to supply power from the storage battery device to the power load.

  According to this aspect, when the storage battery device starts to supply power to the power load, the predetermined set value is determined, so that the operable time of the storage battery device is determined at the start of power supply to the power load of the storage battery device. Can do.

  Moreover, in one aspect of the power supply system according to the present invention, the power supply system further includes a self-sustained operation detector that detects whether or not the power generator receives power from the power system, and the controller includes the power generator that is connected to the power system. The power generation device and the storage battery device are controlled so that the power measured by the power meter becomes the predetermined power during a period when the self-sustained operation detector detects that no power is received from It is good also as.

  When a power failure occurs and power supply from the commercial power system stops, the power load cannot receive power supply from the power system, so the power load receives power supply from the power generator or storage battery device . Therefore, since the frequency of use of the storage battery device is high at the time of a power failure, the operable time of the storage battery device is likely to be shortened due to the power consumption associated with the activation of the storage battery device, and the function of the storage battery is likely to deteriorate in a short period of time.

  According to this aspect, since the storage battery device continues to supply the predetermined power during the period when the power supply from the power system is stopped due to a power failure or the like, the operation of the storage battery device is performed by the power consumption accompanying the activation of the storage battery device. It can suppress that possible time becomes short or the function of a storage battery falls for a short period.

  Moreover, in one aspect of the power supply system according to the present invention, the storage battery device includes at least a first storage battery and a second storage battery, and the first storage battery and the The supply power of one of the second storage batteries is controlled to be the predetermined power, the power generation device is controlled to change the amount of power generation at a predetermined rate, and the controller is It is assumed that the storage unit that stores the maximum power generation amount of the power generation device in advance, and that the power consumption of the power load is changed to the maximum power generation amount, and from the assumption until the maximum power generation amount is changed. An estimation unit that estimates the amount of power that cannot be supplied by the power generation device and the one storage battery as an estimated insufficient power amount, and a comparison unit that compares the estimated insufficient power amount and the charged power amount of the one storage battery When charged electrical energy of the one battery is less than the estimated insufficient amount of power, and a switching unit for switching the battery to supply the predetermined power to another battery from the one battery may be.

  In a power generation device such as a fuel cell system, since the amount of change in output power (ratio of power generation amount) is small, it may not be possible to immediately respond to sudden changes in power consumption of the power load. According to this aspect, by using a plurality of storage batteries, the estimated insufficient power amount is compared with the charged power amount of the storage battery that is currently supplying the predetermined power, and the charged power amount is estimated to be the estimated insufficient power amount. If smaller, the storage battery that continues to supply predetermined power is switched from one storage battery to the other. Thereby, the amount of electric power that cannot be covered by the power generation device when the power generation device cannot cope with the sudden change in the power consumption of the power load can be supplied by the other storage battery instead of one storage battery.

  Alternatively, in one aspect of the power supply system according to the present invention, the storage battery device includes at least a first storage battery and a second storage battery, and the first storage battery and the The supply power of one of the second storage batteries is controlled to be the predetermined power, the power generation device is controlled to change the amount of power generation at a predetermined rate, and the controller is Assuming that the startup power amount consumed when the power generation device is activated and the maximum power generation amount of the power generation device are stored in advance, and the power consumption of the power load is changed to the maximum power generation amount, An estimation unit that estimates an amount of electric power that cannot be supplied by the power generation device and the one storage battery from the assumption until the maximum electric power generation amount is changed, and the estimation insufficient A comparison unit that compares the power amount and the charging power amount of the one storage battery, and compares the starting power amount and the charging power amount of the one storage battery, and the charging power amount of the one storage battery is the estimated insufficient power A storage battery for supplying the predetermined power amount from the one storage battery to the other storage battery in at least one of a case where the amount of charging power is less than the amount and a case where the charging power amount of the one storage battery is less than the starting power amount. It is good also as having a switching part switched to.

  When a power failure occurs, the operation of the power generation device such as the fuel cell system may be temporarily stopped. In this case, a predetermined amount of startup power is required until the power generation device is started and power can be supplied. In addition, as described above, a power generation device such as a fuel cell system may not be able to immediately respond to a sudden change in power consumption of the power load because the amount of change in output power is small.

  According to this aspect, when the estimated insufficient power amount is compared with the charged power amount of the storage battery that supplies the predetermined power, the charge power amount is smaller than the estimated insufficient power amount, and the household fuel cell system The starting power amount of the battery and the charging power amount of the storage battery that supplies the predetermined power are compared, and if the charging power amount is at least one of the cases where the charging power amount is smaller than the starting power amount, the predetermined power is continuously supplied. The storage battery is switched from one storage battery to the other storage battery. As a result, the amount of power that cannot be handled by the power generation device in the case where the output power of the power generation device cannot cope with a sudden change in the power consumption of the power load and the predetermined start-up power amount to start the stopped power generation device It is possible to cover the other storage battery instead of one storage battery.

  Furthermore, in one aspect of the power supply system according to the present invention, when the one storage battery is supplying power to the power load, the controller stores the other storage battery so that the other storage battery performs charging. May be controlled.

  According to this aspect, while one storage battery is supplying predetermined power to the power load, the other storage battery can be charged. Thereby, the time which can supply electric power to an electric power load by an electric power supply system can be lengthened. In particular, a long-time independent operation is required at the time of a power failure, but according to this aspect, it is possible to realize a power supply system capable of a long-term independent operation.

  In the aspect of the power supply system according to the present invention, the controller may determine a predetermined first predetermined power when the power consumption of the power load exceeds the maximum power generation amount of the power generator. Until the time, the power required by the power load is supplied to the power generation device and the storage battery device, and after the first predetermined time has elapsed, the power supplied from the power generation device and the storage battery device to the power load is It may be reduced to less than the excess power.

  If the power generation device is a fuel cell system, etc., as long as fuel gas continues to be supplied, power generation can be performed and the maximum power generation amount can be handled, but the power consumption power consumption is the maximum power generation amount of the power generation device. When exceeding, it will cover the excess electric power by the storage battery device. However, if the state in which the power consumption of the power load exceeds the maximum power generation amount of the power generation device (excess power state) continues, the charging power amount of the storage battery will eventually disappear, which will be extremely inconvenient for the user. For example, when the amount of power charged in the storage battery is lost during a power failure, it is not possible to secure the amount of power required by the power load that exceeds the maximum power generation amount of the power generator.

  Therefore, according to this aspect, even if an excess power state occurs, the output power from the storage battery device is a predetermined power, and the power required by the power load is generated until the predetermined first predetermined time. The power supplied from the device and the storage battery device and after the first predetermined time has elapsed, the power supplied from the power generation device and the storage battery device to the power load is reduced to less than the excess power. As a result, all the power required by the power load can be continuously supplied until the first predetermined time, and a constant power can be continuously supplied to the power load even after the first predetermined time has elapsed. It becomes. Moreover, it can prevent that the charge electric energy of a storage battery runs out in a short time.

  In the aspect of the power supply system according to the present invention, the controller stores a plurality of combinations of the excess power and the first predetermined time, and the plurality of combinations has a value of the excess power. The first predetermined time may be set longer as the time decreases.

  Further, in one aspect of the power supply system according to the present invention, each of the power generation device and the storage battery device is a DC power supply even when the power generation device and the storage battery device cannot receive power from an electric power system. It is good also as providing the inverter which converts into alternating current power which can be supplied to the said electric power load.

  Alternatively, in one aspect of the power supply system according to the present invention, each of the power generation device and the storage battery device may include an inverter that converts DC power into AC power that can be supplied to the power system.

  Moreover, the aspect of the power supply system according to the present invention may be configured such that the controller acquires a measurement value obtained by the power measuring device via a communication medium.

  An aspect of the power supply method according to the present invention is a power supply method for supplying power to a power load by a power generation device and a storage battery device, wherein the power is supplied from the storage battery device to the power load by a power meter. And controlling the power generation device and the storage battery device so that the power measured by the power meter becomes a predetermined power greater than zero during a period in which the power load consumes power. It is characterized by.

  Further, in one aspect of the power supply method according to the present invention, the power supplied from the storage battery device to the power load is continuously changed to the predetermined power during a period in which the power generation device does not receive power from the power system. It is good also as controlling the said electric power generating apparatus and the said storage battery apparatus so that it may become.

  Hereinafter, a power supply system and a power supply method according to embodiments of the present invention will be described with reference to the drawings. Each of the embodiments described below shows a preferred specific example of the present invention. Therefore, numerical values, components, arrangement positions and connection forms of components, steps, order of steps, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept of the present invention are not necessarily required to achieve the object of the present invention. It will be described as constituting a preferred form. In each figure, substantially the same constituent elements are given the same reference numerals.

(Embodiment 1)
Hereinafter, a power supply system and a power supply method according to Embodiment 1 of the present invention will be described.

[Configuration of power supply system]
First, the configuration of the power supply system 1 according to Embodiment 1 of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing the configuration of the power supply system according to Embodiment 1 of the present invention.

  As shown in FIG. 1, a power supply system 1 according to the present embodiment is a distributed power supply system using a fuel cell system as a distributed power supply, and includes a household fuel cell system 10, a storage battery device 20, The commercial power system 30, the power load 40, the distribution board 50, the controller 60, the power measuring device 70, and the self-sustaining operation detector 80 are configured. In the present embodiment, when the power supply from the commercial power system 30 is stopped due to a power failure or the like, the home fuel cell system 10 and the storage battery device 20 can be used for independent operation.

  The household fuel cell system 10 is an example of a power generator, and includes a fuel cell main body 11 and a grid interconnection inverter 12. The fuel cell main body 11 is, for example, a power generator main body that generates DC power from a fuel gas mainly composed of hydrogen and oxygen. The grid interconnection inverter 12 is a DC / AC power converter that converts DC power generated by the fuel cell body 11 into AC power. Although not shown, the home fuel cell system 10 is also a heat exchanger for recovering exhaust heat generated from the fuel cell main body 11 and converts surplus power from the fuel cell main body 11 into heat. And a hot water storage tank for storing hot water obtained by using heat recovered by the heat exchanger or heat converted by the heater.

  Further, the home fuel cell system 10 requires a predetermined power consumption (startup power) for a certain time when the fuel cell main body 11 is started. That is, when the fuel cell main body 11 is started, a predetermined amount of starting power is required. During normal times (when electric power can be supplied from the commercial power system 30), the household fuel cell system 10 generates power based on the AC power of the commercial power system 30. Specifically, the home fuel cell system 10 generates power by synchronizing the frequency (phase) of the power generated by itself with the frequency (phase) of the AC power of the commercial power system 30. Synchronization with the frequency of the commercial power grid 30 is performed by the grid interconnection inverter 12.

  The electric power generated by the home fuel cell system 10 is supplied to the electric power load 40 via the distribution board 50. Further, the home fuel cell system 10 is communicably connected to the controller 60, and the output power (power generation amount) of the home fuel cell system 10 can be set by the controller 60 and, if necessary, It can also be changed by the controller 60. As such a household fuel cell system 10, for example, a household fuel cell system in which the fuel gas is city gas and the output power range is 200 W to 750 W (maximum power generation amount is 750 W) can be used.

  The home fuel cell system 10 can generate power during normal times (non-power failure) and also generate power (in-house power generation) during non-normal times (power failure) as long as fuel gas is supplied. be able to.

  The storage battery device 20 includes a storage battery 21 and a grid interconnection inverter 22. The storage battery 21 is a secondary battery that can be repeatedly charged and discharged, and outputs DC power during discharging. The grid interconnection inverter 22 is a DC / AC power converter that converts DC power output from the storage battery 21 into AC power.

  The power output from the storage battery device 20 is supplied to the power load 40 via the distribution board 50. The storage battery device 20 can also supply power to the home fuel cell system 10. For example, when starting up the home fuel cell system 10 (fuel cell main body 11), power (startup power) necessary for the start-up is supplied to the home fuel cell system 10. The storage battery device 20 is communicably connected to the controller 60, and the output power of the storage battery device 20 can be set by the controller 60 and can be changed by the controller 60 as necessary. . In such a storage battery device 20, for example, a storage battery 21 having a discharge capacity of 6 kWh or less (total capacity of 6 kWh) can be used.

  The commercial power system (power system) 30 is a system that supplies AC power from an electric power company to consumers, and is a system power supply that supplies AC power having a predetermined voltage and a predetermined frequency to consumers. The commercial power system (commercial system power source) 30 supplies, for example, 200 V, 50 Hz / 60 Hz AC power to the consumer.

  The power load 40 is one or a plurality of load devices that consume power in the consumer, and consumes AC power supplied from the household fuel cell system 10, the storage battery device 20, or the commercial power system 30. The power load 40 is a domestic load such as an electric product such as a refrigerator, an air conditioner, a television, a microwave oven, or a lighting device used in a general household.

  The distribution board 50 is for selecting the AC power from the household fuel cell system 10, the storage battery device 20 and the commercial power system 30 as desired and supplying it to a load in the power supply system 1 such as the power load 40. Yes, it includes a switch 51, a switch 52, a circuit breaker 53, and a circuit breaker 54.

  The output side of the grid-connected inverter 12 of the home fuel cell system 10 is connected to the distribution board 50 by a switch 51, and the power supplied from the home fuel cell system 10 to the power load 40 is controlled by the switch 51. can do. For example, when the switch 51 is closed, power can be supplied from the home fuel cell system 10 to the power load 40, while when the switch 51 is opened, power is supplied from the home fuel cell system 10 to the power load 40. Can be stopped.

  The output side of the grid interconnection inverter 22 of the storage battery device 20 is connected to the distribution board 50 by a switch 52, and the power supplied from the storage battery device 20 to the power load 40 can be controlled by the switch 52. For example, when the switch 52 is closed, power can be supplied from the storage battery device 20 to the power load 40, while when the switch 52 is opened, power supply from the storage battery device 20 to the power load 40 can be stopped. . In addition, a power measuring device 70 is provided on the connection path between the output side of the grid interconnection inverter 22 of the storage battery device 20 and the switch 52, and the power measuring device 70 can measure the output power of the storage battery device 20. it can.

  The commercial power system 30 is connected to the distribution board 50 by a circuit breaker 53, and the power supplied from the commercial power system 30 can be controlled by the circuit breaker 53. For example, when the circuit breaker 53 is turned off, the commercial power system 30 and the distribution board 50 are connected, and the household fuel cell system 10, the storage battery device 20, and the power load 40 receive power from the commercial power system 30. The supply can be received. On the other hand, when the circuit breaker 53 is opened, the commercial power system 30 and the distribution board 50 are disconnected, and the household fuel cell system 10, the storage battery device 20, and the power load 40 supply power from the commercial power system 30. It becomes a state that can not be received.

  The customer's power load 40 is connected to the distribution board 50 by a circuit breaker 54, and the power supplied to the power load 40 can be controlled by the circuit breaker 54. For example, when the circuit breaker 54 is cut off, the power load 40 and the distribution board 50 are connected, and the power load 40 supplies power from the home fuel cell system 10, the storage battery device 20, and the commercial power system 30. Ready to receive. On the other hand, when the circuit breaker 54 is opened, the power load 40 and the distribution board 50 are cut off, and the power load 40 supplies power from the household fuel cell system 10, the storage battery device 20, and the commercial power system 30. It becomes a state that can not be received.

  The controller 60 is communicably connected to the home fuel cell system 10 and the storage battery device 20, and controls the home fuel cell system 10 and the storage battery device 20. The controller 60 is also communicably connected to the power measuring device 70 and the self-sustaining operation detector 80, and acquires the measurement result of the power measuring device 70 and the detection result of the self-sustaining operation detector 80.

  The controller 60 controls the household fuel cell system so that the power measured by the power meter 70 becomes a predetermined power (> 0 W) having a value greater than zero during the period when the power load 40 is consuming power. 10 and the storage battery device 20 are controlled. That is, the controller 60 performs control so that predetermined power having a value larger than zero is supplied to the power load 40 by the storage battery device 20 continuously while the power load 40 is consuming power.

  Specifically, during the period when the power load 40 is consuming power, the current value measured by the power meter 70 is controlled to be a predetermined current value (> 0 A). The storage battery 21 of the storage battery device 20 continues to be discharged. Thereby, the storage battery device 20 continues to supply predetermined power to the power load 40.

  The power meter 70 is a device that measures the power at the attached position. In the present embodiment, the power measuring device 70 is arranged on the connection path between the output side of the storage battery device 20 and the power load 40 and measures the power output by the storage battery device 20. Specifically, the power measuring device 70 is a current measuring device that measures a current value (alternating current) flowing from the storage battery device 20 toward the power load 40, and for example, a CT (Current Transformer) sensor can be used. The power measuring device 70 is communicably connected to the controller 60, and the measurement result (current value) of the power measuring device 70 is output to the controller 60.

  The self-sustained operation detector 80 is provided in a connection path between the home fuel cell system 10 and the commercial power system 30 and detects whether the home fuel cell system 10 receives power from the commercial power system 30. It is a detector. That is, the self-sustained operation detector 80 can detect whether or not the home fuel cell system 10 is operating without being supplied with power from the commercial power system 30 during a power failure or the like (self-supporting operation). As described above, the self-sustained operation detector 80 is provided to detect that the home fuel cell system 10 and the storage battery device 20 are not connected to the commercial power system 30. Specifically, the self-sustained operation detector 80 is a current detector that detects a current value flowing between the commercial power system 30 and the home fuel cell system 10, and for example, a CT sensor can be used. The self-sustained operation detector 80 is communicably connected to the controller 60, and the detection result (current value) is output to the controller 60.

[Operation of power supply system]
Next, the operation (current supply method) of the power supply system 1 according to Embodiment 1 of the present invention will be described with reference to FIG. 1 and FIG. FIG. 2 is a flowchart for explaining the operation at the time of a power failure in the power supply system according to Embodiment 1 of the present invention.

  First, in the case of normal time (when there is no power failure), that is, when the customer can receive power supply from the commercial power grid 30 of the electric utility, the switchboard 51 and the circuit breaker are provided in the distribution board 50. 53 and the circuit breaker 54 are in a closed state, and the customer's power load 40 can be supplied with power using the commercial power system 30 and the home fuel cell system 10.

  Further, in a normal time, the storage battery device 20 can also charge the storage battery 21 by receiving power supplied from the commercial power system 30 or the household fuel cell system 10. In this case, the storage battery 21 is also one of the loads. Furthermore, after the charging of the storage battery 21 is completed, the switch 52 of the distribution board 50 is closed and the storage battery 21 is discharged to supply power from the storage battery device 20 to the power load 40.

  On the other hand, in the case of a power failure (non-normal time), that is, when the power supply from the commercial power system 30 of the electric power company to the consumer is stopped, the distributed power source (the home fuel cell system 10 and the storage battery device 20) is used. Use for self-sustained operation.

  First, when a power failure occurs, as shown in FIG. 2, the switch 51 is opened to temporarily stop power supply from the home fuel cell system 10, and the circuit breaker 53 is opened to separate from the commercial power system 30. The board 50 is cut off (step S11). At this time, when power is being supplied from the storage battery device 20 to the power load 40, the switch 52 is opened to temporarily stop the power supply from the storage battery device 20. Thus, when performing a self-sustained operation using a distributed power source, the distributed power source and the commercial power system 30 are temporarily disconnected.

  Next, the controller 60 detects whether or not the home fuel cell system 10 and the storage battery device 20 are receiving power from the commercial power system 30 by the self-sustained operation detector 80, and the home fuel cell system 10 and the storage battery are detected. It is confirmed that the device 20 is not connected to the commercial power system 30 (step S12). That is, it is confirmed that the household fuel cell system 10 and the storage battery device 20 are not supplied with power from the commercial power system 30. In the present embodiment, the above confirmation is performed by detecting whether or not current is flowing by the self-sustained operation detector 80 (CT sensor). Specifically, when the current value measured by the self-sustained operation detector 80 (CT sensor) is zero, it can be confirmed that the home fuel cell system 10 and the storage battery device 20 are not connected to the commercial power system 30.

  Thereafter, the switch 51, the switch 52, and the circuit breaker 54 are closed, and the home fuel cell system 10 and the storage battery device 20 are activated to start the independent operation. Thus, even if the power supply from the commercial power system 30 is stopped due to a power failure, by supplying power to the power load 40 using the household fuel cell system 10 and the storage battery device 20, Independent operation can be performed.

  In this embodiment, when performing a self-sustained operation, the power supplied from the storage battery device 20 to the power load 40 is measured by the power meter 70, and the power measurement is performed during the period in which the power load 40 is consuming power. The household fuel cell system 10 and the storage battery device 20 are controlled so that the supply power of the storage battery device 20 measured by the container 70 becomes a predetermined power (power value) greater than zero (step S13). That is, the controller 60 performs control such that the storage battery device 20 continues to supply predetermined power during a period when the power load 40 is consuming power during a power outage.

  In this case, the value of the predetermined power that continues to be supplied at the time of a power outage can be a predetermined set value or more. Further, the value of the predetermined power is smaller than the maximum output power of the storage battery device 20. For example, the value of the predetermined power can be 0 to 200 W.

  In the present embodiment, the output (predetermined power) of the storage battery device 20 is controlled to be the same value as the predetermined set value, and the predetermined power output from the storage battery device 20 is a constant current value. Is set to The predetermined set value can be set to the minimum power that should be supplied to the power load 40 required at the time of a power failure. Specifically, one or a plurality of power values that are desired to be supplied even at the time of a power failure. The power consumption of the load device can be set. For example, if a load device to which power is to be supplied even during a power failure is a refrigerator, the power consumption is about 100 W, so the predetermined set value can be set to 100 W. In this way, by setting the predetermined power supplied by the storage battery device 20 to a predetermined set value or more, it is possible to continue supplying power from the storage battery device 20 to the power load 40 that is required even during a power failure. it can.

  Here, the relationship between the power consumption of the power load 40 after the occurrence of a power failure and the power supplied to the distributed power source (the household fuel cell system 10 and the storage battery device 20) will be described with reference to FIG. FIG. 3 is a diagram showing a transition of power during a power failure period in the power supply system according to Embodiment 1 of the present invention.

  As shown in FIG. 3, when a power failure occurs at time T0, the power supply system 1 operates as described above (steps S11 to S13) and starts a self-sustaining operation. Thereby, during the self-sustained operation (during the power failure), predetermined power equal to or higher than a predetermined set value is continuously supplied from the storage battery device 20 to the power load 40. In the present embodiment, the output (predetermined power) of the storage battery device 20 is the supplied power (solid line in FIG. 3) of the storage battery device 20, and the output of the storage battery device 20 is a predetermined set value ( It is controlled to be the same constant value as the broken line in FIG.

  The predetermined set value is determined when the controller 60 starts supplying predetermined power from the storage battery device 20 to the power load 40. Thereby, the operation possible time of the storage battery device 20 can be determined at the start of power supply to the power load 40 of the storage battery device 20. The predetermined set value may be set in advance before a power failure occurs.

  In addition, after time T0, the power consumption (instantaneous power consumption) of the power load 40 during a power failure is provided by the power supplied from the household fuel cell system 10 and the power supplied from the storage battery device 20. Specifically, as shown in FIG. 3, the power supplied from the storage battery device 20 to the power load 40 is a constant value regardless of fluctuations in the power consumption of the power load 40. Further, the remaining power obtained by subtracting the power supplied from the storage battery device 20 from the power consumed by the power load 40 is covered by the power supplied from the home fuel cell system 10. Therefore, the power supplied from the household fuel cell system 10 to the power load 40 varies with the variation in the power consumption of the power load 40.

In FIG. 3, the area S _SB indicates the amount of power (Wh) that the storage battery device 20 supplies to the power load 40 at the time of a power failure, and the area S _FC is the power of the household fuel cell system 10 at the time of the power failure. The amount of electric power (Wh) supplied to the load 40 is shown.

  Further, during the power failure period, the household fuel cell system 10 may always generate more power than the power consumed by the power load 40 in order to cope with fluctuations in the power consumption of the power load 40. For example, the fuel cell main body 11 may be operated with the maximum capacity (maximum power generation amount). As a result, the power (power generation amount) generated by the household fuel cell system 10 can easily follow the power consumed by the power load 40. In this case, surplus power that cannot be consumed by the power load 40 out of the amount of power generated by the home fuel cell system 10 is used for surplus power consumption (such as a heater) provided in the home fuel cell system 10. Can be consumed.

  As described above, according to the power supply system 1 according to the present embodiment, the power measurement is performed during the period in which the power load 40 is consuming power when the power supply from the commercial power system 30 is stopped due to a power failure or the like. The power measured by the container 70 is controlled to be a predetermined power, and the output power (supplied power) of the storage battery device 20 is a predetermined power. That is, at the time of a power failure, the storage battery device 20 continues to supply predetermined power while the power load 40 is consuming power. Thereby, since the frequency | count that the storage battery apparatus 20 starts and stops can be reduced, the power consumption accompanying the starting of the storage battery apparatus 20 can be reduced. Therefore, it is possible to suppress a reduction in the operable time of the storage battery device 20.

  Furthermore, according to the power supply system 1 according to the present embodiment, the number of times of starting and stopping of the storage battery device 20 is reduced, so that the number of repetitions of charging and discharging of the storage battery 21 can also be reduced. In particular, since the current value measured by the power meter 70 is less than or equal to the maximum output current of the storage battery device 20, there is no mode in which the storage battery device 20 operates at the maximum output current. It can be further reduced. Thereby, it can suppress that the function of the storage battery 21 falls in a short period with the charging / discharging cycle, the liquid leak of the storage battery 21 generate | occur | produces, or the output voltage of the storage battery apparatus 20 falls. Therefore, the reliability of the storage battery device 20 is improved.

  Furthermore, according to the electric power supply system 1 which concerns on this Embodiment, the rapid discharge of the storage battery 21 can be suppressed by making the output electric power of the storage battery apparatus 20 in a power failure period into predetermined power. In particular, rapid discharge of the storage battery 21 can be avoided by setting the output power of the storage battery device 20 to a constant value that does not change. Thus, by suppressing the rapid discharge of the storage battery 21, it can suppress that the function of the storage battery 21 falls in a short period of time.

  Furthermore, it is difficult for the storage battery device 20 to output high power suddenly from a state where the output power is zero (off state). That is, it is difficult for the storage battery device 20 to suddenly change from an off state to a high output state. On the other hand, in this Embodiment, since the storage battery apparatus 20 continues supplying the predetermined electric power larger than zero, even if it becomes necessary to output high electric power suddenly, it can respond easily.

  In the present embodiment, when the supply of power from the storage battery device 20 to the power load 40 is started, the minimum power value (predetermined set value) supplied to the power load 40 is the charge power amount of the storage battery 21 ( It is preferable to determine according to (charge amount). Thereby, the driveable time of the storage battery apparatus 20 can be adjusted.

  For example, when a power failure occurs, when the supply of power from the storage battery device 20 to the power load 40 is started, the controller 60 determines a set value based on the charge amount of the storage battery 21 of the storage battery device 20. More specifically, as shown in FIG. 4, when the amount of charge of the storage battery 21 is smaller than that in the case of full charge, the predetermined set value is set to a value lower than that in the case of full charge of the storage battery 21. The home fuel cell system 10 and the storage battery device 20 are controlled. In addition, also in the case of FIG. 4, the electric power (solid line in FIG. 4) which the storage battery device 20 continues to supply and a predetermined set value (broken line) are set to the same value. Thus, by setting the predetermined set value small when the charge amount of the storage battery 21 is decreasing, the dischargeable period of the storage battery 21 can be lengthened, and the storage battery 21 can be extended. Thereby, the driving | operation possible time of the storage battery apparatus 20 can be lengthened.

  Moreover, in this Embodiment, although the output electric power of the storage battery apparatus 20 at the time of a power failure was made into the constant value without a change, as shown in FIG. 3, it is not restricted to this. For example, if power is continuously supplied from the storage battery device 20, the amount of charge of the storage battery 21 decreases with the passage of time. Therefore, as shown in FIG. 5, the controller 60 outputs the output of the storage battery device 20 with the passage of the power failure period. You may control so that electric power may be reduced gradually. As described above, by gradually reducing the output power from the storage battery device 20 as time passes, the operable time of the storage battery device 20 can be lengthened, and the number of repetitions of charging and discharging of the storage battery 21 can be further reduced. it can. Therefore, it can further be suppressed that the function of the storage battery 21 is reduced in a short period of time along with the charge / discharge cycle, the liquid leakage of the storage battery 21 is generated, or the output voltage is reduced. In addition, the output power of the storage battery device 20 may be decreased stepwise or may be varied up and down.

  Moreover, in this Embodiment, although the controller 60 acquired the measured value (electric current value) by the electric power measuring device 70 and the independent operation detector 80 with the electric wire (wired), it is not restricted to this. For example, the controller 60 may be configured to acquire measurement values obtained by the power meter 70 and the self-sustaining operation detector 80 via a wireless communication medium.

(Embodiment 2)
Next, a power supply system and a power supply method according to Embodiment 2 of the present invention will be described.

[Configuration of power supply system]
First, the configuration of the power supply system 2 according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 6 is a block diagram showing the configuration of the power supply system according to Embodiment 2 of the present invention. Note that in this embodiment, constituent elements having the same functions as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified.

  The power supply system 2 according to the present embodiment is different from the power supply system according to the first embodiment including one storage battery in that it includes a plurality of storage batteries.

  As shown in FIG. 6, the power supply system 2 according to the present embodiment is a distributed power supply system using a fuel cell system as a distributed power supply, as in the first embodiment. The first storage battery device 20a, the second storage battery device 20b, the commercial power system 30, the power load 40, the distribution board 50, the controller 60, the first power meter 70a, and the second power measurement. 70b. In the present embodiment, when power supply from the commercial power system 30 is stopped due to a power failure or the like, the home fuel cell system 10, the first storage battery device 20a, and the second storage battery device 20b are used to perform independent operation. be able to.

  Each of first storage battery device 20a and second storage battery device 20b has the same configuration and function as storage battery device 20 in the first embodiment. That is, the first storage battery device 20 a includes a first storage battery 21 a having the same configuration as the storage battery 21 and a first grid connection inverter 22 a having the same configuration and function as the grid connection inverter 22. The second storage battery device 20 b includes a second storage battery 21 b that has the same configuration and function as the storage battery 21, and a second system connection inverter 22 b that has the same configuration and function as the system connection inverter 22. .

  The distribution board 50 in the present embodiment includes a switch 52a and a switch 52b in place of the switch 52 of the first embodiment. That is, two switches 52a and 52b are arranged corresponding to the two first storage battery devices 20a and the second storage battery device 20b. The switch 52a and the switch 52b have the same configuration and function as the switch 52 in the first embodiment.

  The controller 60 in the present embodiment is communicably connected to the home fuel cell system 10, the first storage battery device 20a, and the second storage battery device 20b. The home fuel cell system 10 and the first storage battery The device 20a and the second storage battery device 20b are controlled. The controller 60 is also communicably connected to the first power meter 70a, the second power meter 70b, and the self-sustained operation detector 80, and the measurement result of the first power meter 70a, the first 2 The detection results of the power measuring device 70b and the self-sustaining operation detector 80 are acquired.

  In the present embodiment, the controller 60 is a predetermined power whose value measured by the first power meter 70a or the second power meter 70b is greater than zero during the period when the power load 40 is consuming power. The household fuel cell system 10, the first storage battery device 20a, and the second storage battery device 20b are controlled so as to achieve electric power (> 0 W). In other words, the controller 60 selects one of the first storage battery device 20a and the second storage battery device 20b, and the power load 40 is selected by the selected storage battery device during the period when the power load 40 is consuming power. Is controlled so as to be continuously supplied with a predetermined electric power having a value larger than zero.

  Specifically, during the period when the power load 40 is consuming power, the current value measured by the first power measuring device 70a or the second power measuring device 70b becomes a predetermined current value (> 0A). In this period, the storage battery (the first storage battery 21a or the second storage battery 21b) of the selected storage battery device continues to be discharged. Thereby, the storage battery device selected from the first storage battery device 20 a or the second storage battery device 20 b continues to supply predetermined power to the power load 40.

  Furthermore, the controller 60 in the present embodiment includes a storage unit 61, an estimation unit 62, a comparison unit 63, and a switching unit 64.

  The storage unit 61 stores in advance the maximum power generation amount of the home fuel cell system 10 and also stores in advance the amount of startup power consumed when the home fuel cell system 10 is started up. Note that the startup power amount of the household fuel cell system 10 can be calculated by, for example, an integrated value of power consumption (startup power) required for startup and time required for startup (startup time). The unit 61 may store the activation power and the activation time.

  In the case where it is assumed that the power consumption of the power load 40 is changed to the maximum power generation amount of the household fuel cell system 10, the estimation unit 62 assumes that the home power supply is changed from the assumption to the maximum power generation amount. The fuel cell system 10 and the first storage battery device 20a (or the second storage battery device 20b) estimate the amount of power that cannot be supplied to the power load 40. This estimated power amount is set as an estimated insufficient power amount.

  The comparison unit 63 uses the estimated shortage electric power estimated by the estimation unit 62 and the storage battery (one of the first storage battery device 20a and the second storage battery device 20b) that supplies predetermined power to the power load 40. The amount of charge power of the storage battery is compared. Further, the comparison unit 63 continues to supply power to the power load 40 among the starting power amount of the household fuel cell system 10 stored in the storage unit 61 and the first storage battery device 20a and the second storage battery device 20b. The amount of charge power of the storage battery in the storage battery device is compared.

  In the switching unit 64, the estimation unit 62 estimates the charging power amount of the storage battery (one storage battery) in the storage battery device that continues to supply power to the power load 40 of the first storage battery device 20 a and the second storage battery device 20 b. If it is less than the estimated insufficient power amount, the storage battery that continues to supply the predetermined power is switched from one storage battery to the other storage battery. Further, the switching unit 64 stores the charge power amount of the storage battery (one storage battery) in the storage battery device that continues to supply power to the power load 40 of the first storage battery device 20 a and the second storage battery device 20 b in the storage unit 61. The storage battery that continues to supply predetermined power is switched from one storage battery to the other storage battery even when it is less than the starting power amount of the household fuel cell system 10 being used.

  The first power measuring device 70a and the second power measuring device 70b have the same configuration and function as the power measuring device 70 in the first embodiment. Specifically, the first power measuring device 70a is a CT sensor, and is disposed in a connection path between the output side of the first storage battery device 20a and the power load 40, and the first load storage device 20a to the power load 40 is provided. Measure the current flowing toward Similarly, the second power measuring device 70b is a CT sensor, and is disposed in a connection path between the output side of the second storage battery device 20b and the power load 40, and is directed from the second storage battery device 20b to the power load 40. Measure the flowing current value. The first power measuring device 70 a and the second power measuring device 70 b are communicably connected to the controller 60, and each measurement result (current value) is output to the controller 60.

[Operation of power supply system]
Next, the operation (power supply method) of the power supply system 2 according to Embodiment 2 of the present invention will be described using FIG. 7 with reference to FIG. FIG. 7 is a flowchart for explaining the operation at the time of a power failure in the power supply system according to Embodiment 2 of the present invention.

  First, in the case of normal time (when there is no power failure), that is, when the customer can receive power supply from the commercial power grid 30 of the electric utility, the switchboard 51 and the circuit breaker are provided in the distribution board 50. 53 and the circuit breaker 54 are in a closed state, and the customer's power load 40 can be supplied with power using the commercial power system 30 and the home fuel cell system 10.

  Further, in normal times, the first storage battery device 20a and the second storage battery device 20b are charged with the first storage battery 21a and the second storage battery 21b in response to the supply of power from the commercial power system 30 or the household fuel cell system 10. Can also be done. Further, after the charging of the first storage battery 21a is completed, the switch 52a of the distribution board 50 is closed, and the first storage battery 21a is discharged to supply power from the first storage battery device 20a to the power load 40. You can also In addition, after the charging of the second storage battery 21b is completed, the distribution board 50 switch 52b is closed and the second storage battery 21b is discharged to supply power from the first storage battery device 20a to the power load 40. You can also.

  On the other hand, in the case of a power failure (non-normal time), that is, when the power supply from the commercial power system 30 of the electric power company to the consumer is stopped, the distributed power source (the household fuel cell system 10 and the first storage battery device 20a) And the self-supporting operation is performed using the second storage battery device 20b).

  First, when a power failure occurs, as shown in FIG. 7, the switch 51 is opened to temporarily stop power supply from the household fuel cell system 10, and the circuit breaker 53 is opened to separate from the commercial power system 30. The electrical panel 50 is cut off (step S21). At this time, when power is supplied from the first storage battery device 20a and the second storage battery device 20b to the power load 140, the switch 52a and the switch 52b are opened, and the first storage battery device 20a and the second storage battery device 20b. The power supply from the storage battery device 20b is also temporarily stopped. Thus, when performing a self-sustained operation using a distributed power source, the distributed power source and the commercial power system 30 are temporarily disconnected.

  Next, the controller 60 detects whether or not the home fuel cell system 10, the first storage battery device 20a, and the second storage battery device 20b are receiving power from the commercial power system 30 by the self-sustaining operation detector 80, It is confirmed that the home fuel cell system 10, the first storage battery device 20a, and the second storage battery device 20b are not connected to the commercial power system 30 (step S22). That is, it is confirmed that the household fuel cell system 10, the first storage battery device 20a, and the second storage battery device 20b are not supplied with power from the commercial power system 30. In the present embodiment, the above confirmation is performed by detecting whether or not current is flowing by the self-sustained operation detector 80 (CT sensor). Specifically, when the current value measured by the self-sustained operation detector 80 (CT sensor) is zero, the household fuel cell system 10, the first storage battery device 20a, and the second storage battery device 20b are connected to the commercial power system 30. It can be confirmed that it is not connected to.

  Thereafter, the switch 51, the switch 52a, the switch 52b, and the circuit breaker 54 are closed together, and the home fuel cell system 10, the first storage battery device 20a, and the second storage battery device 20b are started to operate independently. To start. Thus, even if the power supply from the commercial power system 30 is stopped due to a power failure, the household fuel cell system 10, the first storage battery device 20a, and the second storage battery device 20b are used for the power load 40. Independent operation can be performed by supplying power.

  In the case of performing a self-sustained operation, in the present embodiment, one of the first power meter 70a and the second power meter 70b is one power meter corresponding to one storage battery device that supplies power to the power load 40. The power supplied from the one storage battery device to the power load 40 is measured, and one storage battery device (first storage battery device) measured by one power meter during the period when the power load 40 consumes power. The home fuel cell system 10, the first storage battery device 20a, and the second storage battery device 20b are controlled so that the supply power of the 20a or the second storage battery device 20b) becomes a predetermined power (power value) greater than zero. (Step S23). That is, the controller 60 is in a power outage and during the period when the power load 40 is consuming power, one of the first storage battery device 20a and the second storage battery device 20b receives a predetermined power. Control to keep supplying. Further, the controller 60 controls the other storage battery device to be charged while one of the first storage battery device 20a or the second storage battery device 20b continues to supply the predetermined power. Do.

  In this case, whether the first storage battery device 20a or the second storage battery device 20b is used to supply predetermined power to the power load 40 depends on the charge amounts of the first storage battery 21a and the second storage battery 21b. It can be selected appropriately. For example, the storage battery device with the larger charge amount of the storage battery can be selected.

  Also in the present embodiment, the value of the predetermined power that continues to be supplied at the time of a power outage can be equal to or greater than a predetermined set value and less than the maximum output power of the first storage battery device 20a and the second storage battery device 20b. . Also in the present embodiment, the output of the storage battery device that supplies the predetermined power is controlled to be the same value as the predetermined set value, and the first storage battery device 20a or the second storage battery device 20b outputs The predetermined power to be set is set to a constant current value. In addition, the predetermined set value can be set to the minimum power that should be supplied to the power load 40 required in the event of a power failure, as in the first embodiment. In this way, by setting the predetermined power supplied by the first storage battery device 20a or the second storage battery device 20b to a predetermined set value or more, power is supplied to the power load 40 that is required even during a power failure. You can continue. Also, the predetermined set value is determined when the controller 60 starts to supply predetermined power from the first storage battery device 20a or the second storage battery device 20b to the power load 40, as in the first embodiment. Yes.

  Furthermore, in the power supply system 2 according to the present embodiment, the storage battery device that supplies predetermined power to the power load 40 out of the first storage battery device 20a and the second storage battery device 20b at the time of the occurrence of a power failure, It is configured so that it can be switched according to the remaining capacity.

  Hereinafter, a method for switching a storage battery device (first storage battery device 20a or second storage battery device 20b) that supplies predetermined power to the power load 40 will be described in detail with reference to FIGS. 8 and 9. FIG. 8 is a diagram showing the transition of power during the power failure period in the power supply system according to Embodiment 2 of the present invention, and the relationship between the power consumption of the power load 40 and the power supply of the distributed power source after the power failure occurs. It is shown. FIG. 9 is a flowchart showing a method of switching a storage battery device that supplies predetermined power to the power load in the power supply system according to Embodiment 2 of the present invention.

In the present embodiment, the home fuel cell system 10 is controlled by the controller 60 to change the amount of generated power at a predetermined rate, and the storage unit 61 of the controller 60 is As described above, the startup power amount consumed when the home fuel cell system 10 is started up and the maximum power generation amount of the home fuel cell system 10 are stored in advance. Further, in FIG. 8, area S _SB indicates the amount of power (Wh) supplied by first storage battery device 20a at the time of a power failure, and area S _FC is the power supplied by household fuel cell system 10 at the time of power failure. The quantity (Wh) is shown.

  As shown in FIG. 8, when a power failure occurs at time T0, the power supply system 2 operates as described above (steps S21 to S23) and starts a self-sustaining operation. In this case, since the home fuel cell system 10 is temporarily disconnected from the commercial power system 30 and stopped, the home fuel cell system 10 is used to supply power using the home fuel cell system 10. Must be started. Therefore, as shown in FIG. 8, between the time T0 when the power failure occurs and the time T1 ′ when the household fuel cell system 10 is activated, the household fuel cell system is used as the power consumption of the load in the power supply system. Electric power (starting power) required to start 10 is applied. For this reason, during the period from time T0 to time T1 ′, only the storage battery device (first storage battery device 20a or second storage battery device 20b) uses the power consumption of the power load 40 and the startup power of the household fuel cell system 10. It is necessary to cover the combined power.

  Moreover, since the home fuel cell system 10 starts after time T1 ′, the power load 40 is powered not only by the first storage battery device 20a or the second storage battery device 20b but also by the home fuel cell system 10. Is supplied. However, in the home fuel cell system 10, since the amount of change in output power is small in order to suppress the temperature deviation of the hydrogen generator that generates fuel gas in the fuel cell body 11, the output power is suddenly increased or suddenly increased. Sometimes it cannot be lowered. As described above, in the home fuel cell system 10, when the operation is once stopped and then restarted, it may be controlled to change the power generation amount by a predetermined change amount (ratio). For example, in the home fuel cell system 10, the amount of change when the output power is increased is about 1 to 2 W / s, and the amount of change when the output power is decreased is about 2 to 3 W / s. For this reason, for a certain period of time after the home fuel cell system 10 is started, the output of the first storage battery device 20a or the second storage battery device 20b is set to a predetermined set value, and the There may be a case where the power consumption of the power load 40 cannot be covered by the first storage battery device 20a or the second storage battery device 20b. For example, as shown in FIG. 8, when the time at which the home fuel cell system 10 can generate power with the maximum power generation after the home fuel cell system 10 is activated is time T1, the time T1 ′ to the time T1 In the meantime, the power load 40 is generated by the household fuel cell system 10 and the first storage battery device 20a or the second storage battery device 20b only by setting the output of the first storage battery device 20a or the second storage battery device 20b as a set value. Can't keep up with the power consumption.

  Therefore, at time T0 to time T1 ′ and time T1 ′ to time T1, the power consumption of the power load 40 that cannot be handled by the household fuel cell system 10 is the output of the first storage battery device 20a or the second storage battery device 20b. It is necessary to respond by raising the electric power above a predetermined set value.

  Therefore, in the present embodiment, which of the first storage battery device 20a and the second storage battery device 20b is used to supply power for the power load 40 that cannot be handled by the household fuel cell system 10? , The power consumption of the power load 40 that cannot be handled by the household fuel cell system 10 at the time T0 to the time T1 ′ and the time T1 ′ to the time T1 is estimated as the estimated insufficient power amount.

Specifically, as shown in FIG. 9, first, assuming that the estimation unit 62 changes the power consumption of the power load 40 to the maximum power generation amount of the home fuel cell system 10, Even if predetermined power is supplied to the power load 40 by the first storage battery device 20a or the second storage battery device 20b during the period from when the power generation amount is changed to the maximum power generation amount, the household fuel cell system 10 The amount of power that cannot be supplied is estimated as the estimated insufficient power amount (P _L ) (step S24).

For example, as shown in FIG. 8, the estimated insufficient power amount (P _L ) from time T0 to time T1 is the amount of power in the power supply system 2 (power load 40) during the period from time T0 to time T1 ′. Of the power supply system 2 and the start-up power amount of the home fuel cell system 10) and the power amount of the load in the power supply system 2 during the period from time T1 ′ to time T1 (power consumption of the power load 40). From the value (A), the amount of power that can be supplied in the power supply system 2 during the period from time T0 to time T1 ′ (the amount of power supplied by the first storage battery device 20a or the second storage battery device 20b) and the time from time T1 ′ The amount of power that can be supplied into the power supply system 2 during the period up to T1 (the amount of power generated by the household fuel cell system 10 and the first storage battery device 20a or the second storage battery device 20b) Can be calculated as a feeding force) and a value obtained by subtracting the added value (B) to (A-b).

Next, as illustrated in FIG. 9, the storage unit that supplies power to the power load 40 among the estimated shortage electric power (P _L ) calculated by the comparison unit 63 and the first storage battery device 20 a and the second storage battery device 20 b. Is compared with the charge amount (P _SB ) of the storage battery (step S25).

And as a result of the comparison in step S25, when the charge amount (P _SB ) of the storage battery device that supplies predetermined power to the power load 40 is less than the estimated insufficient power amount (P _L ) (P _SB <P _L ), The storage battery device that supplies predetermined power to the power load 40 is switched (step S28).

  For example, if the storage battery device that supplies the predetermined power to the power load 40 is set to the first storage battery device 20a, the charge power amount of the first storage battery 21a of the first storage battery device 20a is the estimated insufficient power amount. If it is less, the storage battery device that supplies predetermined power to the power load 40 is switched from the first storage battery device 20a to the second storage battery device 20b.

On the other hand, as a result of the comparison in step S25, when the charge power amount (P _SB ) of the storage battery device that supplies predetermined power to the power load 40 is equal to or greater than the estimated insufficient power amount (P _L ) (P _SB ≧ P _L ) The starting power (P _EMF ) of the household fuel cell system 10 and the charging power of the storage battery in the storage battery device that supplies power to the power load 40 of the first storage battery device 20a and the second storage battery device 20b by the comparison unit 63 The amount (P _SB ) is compared (step S26).

Then, as a result of the comparison in step S26, when the charge amount (P _SB ) of the storage battery device that supplies predetermined power to the power load 40 is less than the home fuel cell system 10 startup power amount (P _EMF ) (P _SB <P _EMF ), the storage battery device that supplies predetermined power to the power load 40 is switched (step S28).

  For example, assuming that the storage battery device that supplies predetermined power to the power load 40 is set to the first storage battery device 20a, the amount of charge power of the first storage battery 21a of the first storage battery device 20a is the household fuel cell. When it is less than the starting power amount of the system 10, the storage battery device that supplies predetermined power to the power load 40 is switched from the first storage battery device 20a to the second storage battery device 20b.

On the other hand, as a result of the comparison in step S26, when the charge power amount (P _SB ) of the storage battery device that supplies predetermined power to the power load 40 is equal to or greater than the start-up power amount (P _EMF ) of the home fuel cell system 10 ( P _SB ≧ P _EMF ), the storage battery device that supplies the power load 40 with the predetermined power without switching the storage battery device that supplies the power load 40 with the predetermined power, and continuously with respect to the power load 40 Then, predetermined power is supplied (step S27).

  For example, assuming that the storage battery device that supplies predetermined power to the power load 40 is set to the first storage battery device 20a, the amount of charge power of the first storage battery 21a of the first storage battery device 20a is the household fuel cell. When it is more than the system 10 starting electric energy, predetermined electric power is supplied with respect to the electric power load 40 using the 1st storage battery apparatus 20a as it is.

  As described above, at time T0 to time T1 ′ and time T1 ′ to time T1, regarding the power consumption of the power load 40 that cannot be handled by the home fuel cell system 10, the first storage battery device 20a and the second storage battery device One of 20b is selected (switched), and its output power is raised from a predetermined set value. In addition, selection (switching) of the 1st storage battery apparatus 20a and the 2nd storage battery apparatus 20b can be performed at time T0, for example.

  Then, returning to FIG. 8, during a power failure period after time T1, a predetermined set value is always set for the power load 40 by the selected one of the first storage battery device 20a and the second storage battery device 20b. The predetermined power described above is supplied.

  Further, after time T1, as in the first embodiment, the power consumption (instantaneous power consumption) of the power load 40 during a power outage is the power supplied from the household fuel cell system 10 and one of the selected storage battery devices ( It is provided by the power supplied from the first storage battery device 20a or the second storage battery device 20b). Specifically, as shown in FIG. 9, regarding the power supplied from one storage battery device (first storage battery device 20a or second storage battery device 20b) to the power load 40, the power consumption of the power load 40 varies. It is a constant value. Further, the remaining power obtained by subtracting the power supplied from one storage battery device (the first storage battery device 20a or the second storage battery device 20b) is supplied by the power supplied from the home fuel cell system 10. Therefore, the power supplied from the household fuel cell system 10 to the power load 40 varies with the variation in the power consumption of the power load 40.

  Similarly to the first embodiment, during the power outage period after time T1, the household fuel cell system 10 uses power consumed by the power load 40 in order to cope with fluctuations in power consumption of the power load 40. You may always have more power generated. For example, the fuel cell main body 11 may be operated with the maximum capacity (maximum power generation amount). Thereby, the electric power (power generation amount) generated by the household fuel cell system 10 can follow the electric power consumed by the electric power load 40. In this case, surplus power that cannot be consumed by the power load 40 out of the amount of power generated by the home fuel cell system 10 is used for surplus power consumption (such as a heater) provided in the home fuel cell system 10. Can be consumed.

  Moreover, in this Embodiment, when one storage battery apparatus selected among the 1st storage battery apparatus 20a and the 2nd storage battery apparatus 20b is supplying electric power to the electric power load 40, it is by the household fuel cell system 10 The storage battery in the other storage battery device may be charged. Thereby, the electric power supply time to the electric power load 40 can be lengthened at the time of the power failure in which long-time independent operation is requested | required.

  As described above, according to the power supply system 2 according to the present embodiment, when the power supply from the commercial power system 30 is stopped due to a power failure or the like, during the period when the power load 40 is consuming power, the first The power measured by the power meter 70a or the second power meter 70b is controlled to be a predetermined power, and the output power (supplied power) of the first storage battery device 20a or the second storage battery device 20b is a predetermined power. It has become electric power. That is, at the time of a power failure, the 1st storage battery apparatus 20a or the 2nd storage battery apparatus 20b continues supplying the predetermined electric power more than a setting value at least during the period when the electric power load 40 is consuming electric power. Thereby, since the frequency | count that the 1st storage battery apparatus 20a and the 2nd storage battery apparatus 20b start and stop can be reduced, the power consumption accompanying the starting of the 1st storage battery apparatus 20a and the 2nd storage battery apparatus 20b can be reduced. it can. Therefore, it is possible to suppress a reduction in the operable time of the first storage battery device 20a and the second storage battery device 20b.

  Furthermore, according to the power supply system 2 according to the present embodiment, the number of times of starting and stopping of the first storage battery device 20a and the second storage battery device 20b is reduced, so that charging / discharging of the first storage battery 21a and the second storage battery 21b is performed. The number of repetitions of can also be reduced. In particular, when the current value measured by the first power measuring device 70a and the second power measuring device 70b is equal to or less than the maximum output current of the first storage battery device 20a and the second storage battery device 20b, the first storage battery device 20a and the second storage battery device 20b. Since there is no mode in which the two storage battery device 20b operates at the maximum output current, the number of repetitions of charging / discharging of the first storage battery 21a and the second storage battery 21b can be further reduced. Thereby, the function of the 1st storage battery 21a and the 2nd storage battery 21b falls in a short period with the charging / discharging cycle, the liquid leakage of the 1st storage battery 21a and the 2nd storage battery 21b occurs, the 1st storage battery apparatus 20a and the 1st It can suppress that the output voltage of 2 storage battery apparatus 20b falls. Therefore, the reliability of the first storage battery device 20a and the second storage battery device 20b is improved.

  Furthermore, according to the power supply system 2 according to the present embodiment, the output power of the first storage battery device 20a or the second storage battery device 20b during the power failure period is set to a predetermined power, so that the first storage battery 21a and the second storage battery 21a Rapid discharge of the storage battery 21b can be suppressed. In particular, rapid discharge of the first storage battery 21a and the second storage battery 21b can be avoided by setting the output power of the first storage battery device 20a and the second storage battery device 20b to constant values that do not change. Thus, by suppressing rapid discharge of the first storage battery 21a and the second storage battery 21b, it is possible to suppress the functions of the first storage battery 21a and the second storage battery 21b from being deteriorated in a short period of time.

  Furthermore, according to the power supply system 2 according to the present embodiment, since the first storage battery device 20a or the second storage battery device 20b continues to supply predetermined power greater than zero, it is necessary to suddenly output high power. Even if this occurs, it can be easily handled.

  Further, in the power supply system 2 according to the present embodiment, the operation of the home fuel cell system 10 is temporarily stopped when a power failure occurs, but thereafter, the power from the first storage battery device 20a or the second storage battery device 20b. Is used to start and start the home fuel cell system 10. Thereby, the household fuel cell system 10 and the 1st storage battery apparatus 20a or the 2nd storage battery apparatus 20b can be continuously used simultaneously. Therefore, when the power supply system 2 according to the present embodiment operates in a grid connection with the commercial power system 30 during normal times, the power supply from the commercial power system 30 stops due to a power failure such as a disaster. In (non-normal time), it is possible to perform self-power generation, and it is useful in both normal time and non-normal time.

  In addition, according to the power supply system 2 according to the present embodiment, the storage battery device that supplies predetermined power to the power load 40 in the event of a power failure is used as the charge power amount (charging) of the first storage battery 21a and the second storage battery 21b. It is switched appropriately according to the capacity. Specifically, the charged power amount of the first storage battery 21a and the second storage battery 21b that supplies the predetermined power is compared with the estimated insufficient power amount, and the charged power amount is greater than the estimated insufficient power amount. If the charging power amount is small, the charging power amount of the storage battery that supplies predetermined power out of the first storage battery 21a and the second storage battery 21b is compared with the starting power amount of the home fuel cell system 10, and the charging power amount is When it corresponds to at least one of the cases where the power is smaller than the starting power amount, the storage battery that continues to supply the predetermined power is switched from one storage battery to the other storage battery. Thereby, when the output power of the home fuel cell system 10 cannot cope with the sudden change in the power consumption of the power load 40, the amount of power that the home fuel cell system 10 cannot handle and the stopped home fuel cell In order to start up the system 10, a predetermined amount of starting power can be supplied by the other storage battery instead of one storage battery.

  In the present embodiment, the two storage batteries of the first storage battery 21a and the second storage battery 21b are configured to be provided in each of the two storage battery apparatuses of the first storage battery apparatus 20a and the second storage battery apparatus 20b. Not limited to this. For example, you may comprise so that one storage battery apparatus may be provided with two storage batteries. In the present embodiment, switching is performed using two storage batteries, but switching may be performed using three or more storage batteries. In this case, the same number of storage battery devices as the storage batteries may be configured to correspond to each of the plurality of storage batteries, or the storage battery devices may be configured with a smaller number than the plurality of storage batteries.

  Also in the present embodiment, as in the first embodiment, when the supply of power from the first storage battery device 20a and the second storage battery device 20b to the power load 40 is started, the minimum supply to the power load 40 The power value (predetermined set value) is preferably determined according to the amount of charge power of the first storage battery 21a and the second storage battery 21b. Thereby, the driveable time of the 1st storage battery apparatus 20a and the 2nd storage battery apparatus 20b can be adjusted.

  Also in the present embodiment, as in the first embodiment, the output power of the first storage battery device 20a and the second storage battery device 20b at the time of a power failure is the first storage battery device 20a and the second storage battery device as the power failure period elapses. You may control so that the output power of 20b may be reduced gradually. Thereby, while the operable time of the 1st storage battery apparatus 20a can be lengthened, the repetition frequency of charging / discharging of the 1st storage battery 21a and the 2nd storage battery 21b can be reduced further. Therefore, the function of the 1st storage battery 21a and the 2nd storage battery 21b falls in a short period with the charging / discharging cycle, the liquid leakage of the 1st storage battery 21a and the 2nd storage battery 21b occurs, or the output voltage falls. Can be further suppressed.

  Also in the present embodiment, similarly to the first embodiment, the measured values (current values) obtained by the first power measuring device 70a, the second power measuring device 70b, and the self-sustaining operation detector 80 are stored on a wireless communication medium. The controller 60 may be configured so as to be acquired via the network.

Further, in the present embodiment, switching of the storage battery device (storage battery) that supplies predetermined power to the power load 40 has been described in the case of a power failure when the home fuel cell system 10 is temporarily stopped. In addition to comparing the charging power amount of the storage battery and the estimated insufficient power amount, the charging power amount of the storage battery and the starting power amount are compared. May be performed when is in the driving state. In this case, since it is not necessary to start up the home fuel cell system 10, it is not necessary to compare the charging power amount of the storage battery with the starting power amount. Hereinafter, the switching method according to the modification in this case will be described in detail with reference to FIGS. 10 and 11. FIG. 10 is a diagram showing a transition of power during a power failure period in the power supply system according to the modification of the second embodiment of the present invention. FIG. 11 is a flowchart illustrating a method of switching a storage battery device that supplies predetermined power to a power load in the power supply system according to the modification of the second embodiment of the present invention. In FIG. 10, the area S _SB indicates the amount of power supplied by the first storage battery device 20 a, and the area S _FC indicates the amount of power supplied by the home fuel cell system 10.

As shown in FIG. 10, when switching the storage battery device that supplies predetermined power to the power load 40 at time T0, first, as shown in FIG. 11, as in step S24 of FIG. The estimated insufficient power amount (P _L ) is estimated (step S24 ′). At this time, as shown in FIG. 10, since the amount of change in the output of the home fuel cell system 10 is small, from time T0 to time T1 (time when the home fuel cell system 10 can generate power with the maximum power generation amount). Since the amount of change in the output of the household fuel cell system 10 is constant until the time T0, if the output power of the storage battery device that supplies predetermined power to the power load 40 remains at a predetermined set value, From time to time T1, there is a case where the power consumption of the power load 40 cannot be achieved by the output from the first household fuel cell system 10 alone. In this modification, the amount of electric power that cannot be handled by the household fuel cell system 10 alone is the estimated insufficient electric energy (P _L ).

Next, as shown in FIG. 11, in the same manner as in step S <b> 25 of FIG. 9, the estimated insufficient power amount (P _L ) and the charging power amount (P P) of the storage battery in the storage battery device that supplies power to the power load 40. _SB ) (step S25 ').

Then, as a result of the comparison in step S25 ′, when the charge power amount (P _SB ) of the storage battery device that supplies the predetermined power to the power load 40 is less than the estimated insufficient power amount (P _L ) (P _SB <P _L ), the storage battery device that supplies predetermined power to the power load 40 is switched (step S28 ′).

On the other hand, as a result of the comparison in step S25 ′, when the charge power amount (P _SB ) of the storage battery device that supplies predetermined power to the power load 40 is equal to or greater than the estimated insufficient power amount (P _L ) (P _SB ≧ P _L ), without switching the storage battery device supplying the predetermined power to the power load 40, using the storage battery device supplying the predetermined power to the power load 40, continuously with respect to the power load 40 Then, predetermined power is supplied (step S27 ′).

  As described above, according to the present modification, the estimated insufficient power amount of the household fuel cell system 10 is compared with the charge power amount of the storage battery that is currently supplying the predetermined power, and the charge power amount is estimated. When it is smaller than the shortage of electric power, the storage battery that continues to supply the predetermined power is switched from one storage battery to the other storage battery. As a result, even if the output power of the home fuel cell system 10 cannot cope with the sudden change in the power consumption of the power load 40, the other storage battery can generate an amount of power that cannot be handled by the home fuel cell system 10. I can cover it.

(Embodiment 3)
Next, a power supply system and a power supply method according to Embodiment 3 of the present invention will be described.

[Configuration of power supply system]
First, the configuration of the power supply system 3 according to Embodiment 3 of the present invention will be described with reference to FIG. FIG. 12 is a block diagram showing a configuration of a power supply system according to Embodiment 3 of the present invention. Note that in this embodiment, constituent elements having the same functions as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified.

  As shown in FIG. 12, the power supply system 3 according to the present embodiment is a distributed power supply system using a fuel cell system as a distributed power supply, as in the first embodiment. And the storage battery device 20, the commercial power system 30, the power load 40, the distribution board 50, the controller 60, and the power measuring device 90.

  The home fuel cell system 10 in the present embodiment has the same configuration and function as the home fuel cell system 10 in the first embodiment, and includes a fuel cell main body 11 and a grid interconnection inverter 12. Although the home fuel cell system 10 in the present embodiment includes the controller 60, the controller 60 may be provided outside the home fuel cell system 10 as in the first embodiment. Absent. The controller 60 in the present embodiment can perform the same control as the controller 60 in the first and second embodiments.

  Moreover, the storage battery device 20 in the present embodiment has the same configuration and function as the storage battery device 20 in the first embodiment, and includes a storage battery 21 and a grid interconnection inverter 22. In addition, the connection point of the storage battery device 20 in the present embodiment is different from the connection point of the storage battery device 20 in the first embodiment, and the storage battery device 20 in the present embodiment includes the household fuel cell system 10 and Interconnection is made on the upstream side closer to the commercial power system 30 than the power load 40.

  The distribution board 50 in the present embodiment includes a power measuring device 90 instead of the self-sustaining operation detector 80. The power measuring device 90 is provided in a connection path between the home fuel cell system 10 and the commercial power system 30. More specifically, the connection point between the storage battery device 20 and the commercial power system 30 and the home fuel cell. It is arranged between the system 10 and the interconnection point of the power load 40. The power measuring device 90 in the present embodiment is a current measuring device that measures a current value flowing between the two interconnection points, and a CT sensor, for example, can be used. The power measuring device 90 is communicably connected to the home fuel cell system 10, and the measurement result (current value) of the power measuring device 90 is output to the controller 60 of the home fuel cell system 10.

  In the power supply system 3 configured as described above, the power measuring device (CT sensor) dedicated to the storage battery device 20 as shown in FIG. 1 is not necessary, and the embodiment is made using one power measuring device 90 (CT sensor). The same control as that of 1 and 2 can be performed.

  Specifically, when a power failure occurs, the home fuel cell system 10 (controller 60) controls the power measuring device 90 so that the power once becomes zero and is supplied by the home fuel cell system 10. Control is performed so that the remaining power that cannot be supplied by the storage battery device 20 is supplied.

  At this time, also in the present embodiment, during the period when the power load 40 is consuming the power, the controller 60 has a predetermined power (> 0 W) in which the power measured by the power meter 90 is greater than zero. Thus, the household fuel cell system 10 and the storage battery device 20 are controlled. For example, during the period when the power load 40 is consuming power, the current value measured by the power meter 90 is controlled to be a predetermined current value (> 0 A). Thereby, the storage battery device 20 continues to supply predetermined power to the power load 40.

  As mentioned above, according to the electric power supply system 3 which concerns on this Embodiment, the effect similar to the electric power supply system 1 in Embodiment 1 can be acquired.

  Furthermore, according to the power supply system 3 according to the present embodiment, a power meter (CT sensor) dedicated to the storage battery device 20 is not required, and the configuration of the power supply system can be simplified.

(Modification)
Hereinafter, modified examples of the power supply system according to Embodiments 1 to 3 will be described.

  In the power supply system according to this modification, the controller 60 determines a predetermined first predetermined time when the power consumption of the power load 40 exceeds the maximum power generation amount of the household fuel cell system 10. Until the power required by the power load 40 is supplied to the household fuel cell system 10 and the storage battery device 20 (or one of the first storage battery device 20a and the second storage battery device 20b), after the first predetermined time has elapsed, The power supplied from the household fuel cell system 10 and the storage battery device 20 (or one of the first storage battery device 20a and the second storage battery device 20b) to the power load 40 is reduced to less than the excess power.

  As mentioned above, according to the power supply system which concerns on this modification, in addition to the effect by the power supply system in Embodiment 1-3, the following effects can be acquired.

  Since the household fuel cell system 10 can generate power as long as fuel gas is continuously supplied, power up to the maximum power generation amount can be supplied to the power consumption of the power load 40. However, when the power consumption of the power load 40 exceeds the maximum power generation amount of the household fuel cell system 10, the excess power is covered by the storage battery device 20 (the first storage battery device 20a or the second storage battery device 20b). . However, in this case, if the state in which the power consumption of the power load 40 exceeds the maximum power generation amount of the household fuel cell system 10 (excess power state) continues, the charge amount of the storage battery 21 (the first storage battery 21a or the second storage battery 21b) (Remaining capacity) gradually decreases and eventually disappears. When the charge amount of the storage battery 21 (the first storage battery 21a or the second storage battery 21b) is exhausted, it becomes extremely inconvenient for the user. For example, after the amount of charge of the storage battery 21 (the first storage battery 21a or the second storage battery 21b) is lost at the time of a power failure, it exceeds the maximum power generation amount of the household fuel cell system 10 among the power required by the power load 40. It will not be possible to secure enough power.

  On the other hand, according to the power supply system which concerns on a modification, even if it becomes said excess electric power state, the output electric power from the storage battery apparatus 20 (the 1st storage battery 21a or the 2nd storage battery 21b) is made into predetermined electric power. However, until the predetermined first predetermined time, the power required by the power load 40 is supplied from the household fuel cell system 10 and the storage battery device 20 (the first storage battery device 20a or the second storage battery device 20b), and the first After the elapse of one predetermined time, the power supplied from the household fuel cell system 10 and the storage battery device 20 (the first storage battery device 20a or the second storage battery device 20b) to the power load 40 is reduced to less than the excess power. As a result, the household fuel cell system 10 and the storage battery device 20 (the first storage battery device 20a or the second storage battery device 20b) continue to supply all the power required by the power load 40 until the first predetermined time. In addition, even after the first predetermined time has elapsed, it is possible to continue to supply constant power to the power load 40. Moreover, it can prevent that the charge amount of the storage battery 21 (the 1st storage battery 21a or the 2nd storage battery 21b) runs out in a short time.

  Further, in this modification, the controller 60 stores a plurality of combinations of excess power and the first predetermined time, and the plurality of combinations seems to increase the first predetermined time as the value of the excess power decreases. You may make it stipulate in.

  For example, the excess power may be set as the power for every 100 W in 1 kW to 2 kW, and the first predetermined time may be set as the predetermined time for each hour from 1 hour to 12 hours so as to correspond to each excess power. it can. That is, 11 types of excess power set to 1.0 kW, 1.1 kW, 1.2 kW,..., 2.0 kW, and 12 types of 1 hour, 2 hours, 3 hours,. Depending on the first predetermined time set to, 132 combinations are possible.

(Other)
The power supply system and the power supply method according to the present invention have been described based on the embodiments and the modifications. However, the present invention is not limited to the above-described embodiments and modifications.

  For example, in the first to third embodiments and the modifications described above, the case where the power supply from the commercial power system 30 is stopped due to a power failure or the like is described, but the present invention is not limited thereto. That is, the present invention can also be applied during normal times (when the power supply from the commercial power system 30 can be received). For example, control is performed so that the power measured by the power meter 70 (the first power meter 70a, the second power meter 70b, or the power meter 90) at a normal time becomes a predetermined power that is equal to or higher than a set value. The storage battery device 20 (first storage battery device 20a, second storage battery device) may continue to supply predetermined power to the power load 40 at times.

  Thereby, since the frequency | count that a storage battery apparatus starts and stops can be reduced, the power consumption accompanying the start of a storage battery apparatus can be reduced. Therefore, it is possible to suppress a reduction in the operable time of the storage battery device. Moreover, since the frequency | count of repetition of charging / discharging of a storage battery can also be reduced by reducing the frequency | count of starting and a stop of a storage battery apparatus, it can also suppress that the function of a storage battery falls in a short period. Furthermore, since the rapid discharge of a storage battery can be suppressed by making output power of a storage battery apparatus into predetermined power, it can also suppress that the function of a storage battery falls in a short period of time.

  In the above first to third embodiments and modifications, the grid-connected inverters 12 and 22 (the first grid-connected inverter 22a and the second grid-connected inverter 22b) are the home fuel cell system 10 and the storage battery. Even when the device 20 (the first storage battery device 20a and the second storage battery device 20b) cannot receive power from the commercial power system 30, the DC power is converted into AC power that can be supplied to the power load 40. An inverter that can be used can be used.

  Alternatively, the home fuel cell system 10 and the storage battery device 20 (first storage battery device 20a, second storage battery device 20b) may be used as the grid connection inverters 12 and 22 (first system connection inverter 22a, second system connection inverter 22b). However, an inverter that converts DC power into AC power that can be supplied to the commercial power system 30 can also be used.

  Moreover, in said Embodiment 1-3 and the modification, although the household fuel cell system 10 was illustrated as an electric power generating apparatus, it is not restricted to this. As the power generation device, a fuel input type power generation device other than the fuel cell system, or a power generation device using natural energy such as a solar cell system having a solar cell or a wind power generation system can be used.

  In the first to third embodiments and the modifications described above, when the power load 40 is consuming power, the storage battery device 20 and the like continue to supply predetermined power, but the power load 40 temporarily supplies power. When the battery is not consumed, the storage battery device 20 (the first storage battery device 20a and the second storage battery device 20b) continues to output a predetermined power for a certain period from when there is no power consumption of the power load 40, and then , Stop power output. The output power of the storage battery device 20 (first storage battery device 20a, second storage battery device 20b) when the power load 40 is not consuming power is a surplus power consumption load (such as a heater) built in the storage battery device 20. ).

  In the first and second embodiments, the controller 60 is configured to exist outside the household fuel cell system 10. However, as in the third embodiment, the household fuel cell system 10 You may comprise so that the controller 60 may be provided.

  The present invention can be realized not only as such a power supply system and power supply method, but also as a program for causing a computer to execute the steps included in the power supply method. Further, such a program is stored in a computer-readable recording medium (for example, a memory card such as a flexible disk, hard disk, CD-ROM, MO, DVD, DVD-ROM, DVD-RAM, BD, USB memory, SD card). And can be distributed via a transmission medium such as the Internet.

  In addition, some or all of the components constituting the power supply system according to the present invention can be realized as an integrated circuit (LSI: Large Scale Integration). These components may be individually made into one chip, or may be made into one chip so as to include a part or all of them. An integrated circuit may be referred to as an IC (Integrated Circuit), a system LSI, a super LSI, or an ultra LSI depending on the degree of integration.

  It should be noted that, in addition to the forms obtained by making various modifications conceived by those skilled in the art with respect to the respective embodiments and modifications, and the components and functions in the respective embodiments and modifications without departing from the spirit of the present invention. Forms realized by arbitrarily combining these are also included in the present invention.

  INDUSTRIAL APPLICABILITY The present invention can be used as a power supply system and a power supply method that include a distributed power supply that is linked to a commercial power system, and is widely used as a distributed power supply system that is useful in both normal and non-normal times. be able to.

1, 2, 3 Electric power supply system 10, 110 Household fuel cell system 11, 111 Fuel cell body 12, 22, 112, 122 Grid-connected inverter 20, 120 Storage battery device 20a First storage battery device 20b Second storage battery device 21, 121 storage battery 21a first storage battery 21b second storage battery 22a first system connection inverter 22b second system connection inverter 30, 130 commercial power system 40, 140 power load 50, 150 distribution board 51, 52, 52a, 52b, 151 , 152 Switch 53, 54, 153, 154 Breaker 60 Controller 61 Storage unit 62 Estimation unit 63 Comparison unit 64 Switching unit 70, 90 Power measurement device 70a First power measurement device 70b Second power measurement device 80 Self-sustained operation detection 100 Distributed power system

Claims (15)

A power generation device that supplies generated power to a power load, a storage battery device that supplies power to the power load, a power measuring device that measures power supplied from the storage battery device to the power load, and a controller. Prepared,
The controller controls the power generation device and the storage battery device so that the power measured by the power meter becomes a predetermined power greater than zero during a period in which the power load is consuming power. To
Power supply system. The predetermined power is not less than a predetermined set value;
The power supply system according to claim 1. The controller determines the predetermined set value according to the amount of charging power of the storage battery device.
The power supply system according to claim 2. The controller determines the predetermined set value when starting to supply power from the storage battery device to the power load.
The power supply system according to claim 2 or 3. A self-sustaining operation detector for detecting whether or not the power generation device is receiving power from the power system;
The controller is configured so that the power measured by the power meter becomes the predetermined power during the period when the self-sustained operation detector detects that the power generation device is not receiving power from the power system. , Controlling the power generation device and the storage battery device,
The power supply system of any one of Claims 1-4. The storage battery device includes at least a first storage battery and a second storage battery, and power supplied to one storage battery of the first storage battery and the second storage battery in the period in which the power load consumes power is Controlled to a predetermined power,
The power generation device is controlled to change the power generation amount at a predetermined rate,
The controller is
A storage unit for storing in advance the maximum power generation amount of the power generation device;
It is assumed that the power consumption of the power load is changed to the maximum power generation amount, and the amount of power that cannot be supplied by the power generation device and the one storage battery between the assumption and the change to the maximum power generation amount. An estimator for estimating the estimated insufficient power amount;
A comparison unit for comparing the estimated insufficient power amount and the charged power amount of the one storage battery;
A switching unit that switches the storage battery that supplies the predetermined power from the one storage battery to the other storage battery when the charge power amount of the one storage battery is less than the estimated insufficient power amount;
The power supply system of any one of Claims 1-5. The storage battery device includes at least a first storage battery and a second storage battery, and power supplied to one storage battery of the first storage battery and the second storage battery in the period in which the power load consumes power is Controlled to a predetermined power,
The power generation device is controlled to change the power generation amount at a predetermined rate,
The controller is
A storage unit that stores in advance the startup power amount consumed when the power generation device is started and the maximum power generation amount of the power generation device;
It is assumed that the power consumption of the power load is changed to the maximum power generation amount, and the amount of power that cannot be supplied by the power generation device and the one storage battery between the assumption and the change to the maximum power generation amount. An estimator for estimating the estimated insufficient power amount;
A comparison unit that compares the estimated insufficient power amount and the charging power amount of the one storage battery, and compares the starting power amount and the charging power amount of the one storage battery,
In a case where the amount of charging power of the one storage battery is less than the estimated insufficient power amount and a case where the amount of charging power of the one storage battery is less than the starting power amount, the predetermined power is A switching unit for switching the storage battery to be supplied from the one storage battery to the other storage battery,
The power supply system of any one of Claims 1-5. The controller controls the other storage battery so that the other storage battery performs charging when the one storage battery supplies power to the power load.
The power supply system according to claim 6 or 7. The controller, when the power consumption of the power load exceeds the maximum power generation amount of the power generator, the power required by the power load until the first predetermined time is determined in advance The power is supplied to the power generation device and the storage battery device, and after the first predetermined time has elapsed, the power supplied from the power generation device and the storage battery device to the power load is reduced to less than the excess power.
The power supply system according to any one of claims 1 to 8. The controller stores a plurality of combinations of the excess power and the first predetermined time,
The plurality of combinations are determined such that the first predetermined time becomes longer as the value of the excess power decreases.
The power supply system according to claim 9. Each of the power generation device and the storage battery device converts DC power into AC power that can be supplied to the power load even when the power generation device and the storage battery device cannot receive power from the power system. Equipped with an inverter,
The power supply system of any one of Claims 1-10. Each of the power generation device and the storage battery device includes an inverter that converts DC power into AC power that can be supplied to a power system.
The power supply system of any one of Claims 1-10. The controller obtains a measured value by the power meter via a communication medium;
The power supply system of any one of Claims 1-12. A power supply method for supplying power to a power load by a power generation device and a storage battery device,
Measure the power supplied from the storage battery device to the power load by a power meter,
Controlling the power generation device and the storage battery device so that the power measured by the power meter becomes a predetermined power of a value greater than zero during a period in which the power load is consuming power.
Power supply method. The power generation device and the storage battery device are controlled so that the power supplied from the storage battery device to the power load continuously becomes the predetermined power during a period when the power generation device is not receiving power from the power system. ,
The power supply method according to claim 14.

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