JP3957727B2 - FUEL CELL SYSTEM, FUEL CELL SYSTEM CONTROL METHOD, AND BUILDING that suppresses peak power consumption below maximum generated power - Google Patents

Description

  The present invention relates to a fuel cell system, a fuel cell system control method, and a building that can appropriately prevent the peak of power consumption from exceeding the maximum power generation amount by a fuel cell. In particular, the present invention relates to a fuel cell system, a fuel cell system control method, and a building that reduce power consumption when a load control unit receives an instruction to reduce power consumption from the fuel cell control unit.

  Conventionally, solar power generation, fuel cells, and the like in each house have been considered as auxiliary power sources for electric power systems. In addition, due to the recent increase in power demand, it is expected that power supply from the power system will be short in the near future. For this reason, in the electric power supply of each house, it is thought that the dependence with respect to distributed power sources, such as photovoltaic power generation and a fuel cell, increases. That is, it is expected that a fuel cell or the like conventionally used as an auxiliary power source functions as a main power source for each house. As such a system, for example, there is a system in which a fuel cell provides power consumed by a load device provided in a house and supplies hot water generated along with power generation of the fuel cell to a hot water storage tank provided in the house ( For example, see Patent Document 1.)

  Generally, a load device that operates using electric power supplied from an electric power system may fluctuate power consumption in a time of about 10 milliseconds. On the other hand, generally, it takes about several hundred milliseconds to change the power generation amount of the fuel cell.

In addition, when the power consumption of the load device reaches a predetermined limit value, the power supply system is maintained stable by cutting off the power supply by the current limiter.
: JP-A-2003-199254

  Conventionally, the fuel cell cannot previously generate the power consumed by the load device before the load device consumes the power. For this reason, when the fuel cell cannot cope with the time fluctuation of the power demand of the load device, the load device may stop operating or may malfunction. In order to avoid this, it is wasteful and undesirable to generate sufficient power in advance with respect to the demand power in the fuel cell.

  In addition, when a plurality of load devices consume power at the same time, the power consumption of the entire system may fluctuate. In such a case, the power generated until the power generated by the fuel cell reaches the demand power is wasted. Furthermore, when the demand power of the entire system is larger than the maximum generated power of the fuel cell, the power supply is interrupted by a current limiter or the like, and the load device completely stops its operation.

  In addition, when the load device cannot receive the necessary power from the fuel cell, the load device may stop operating or may malfunction.

In order to solve such a problem, a fuel cell system in a first embodiment of the present invention includes a fuel cell, a plurality of power loads that runs with power fuel cell is generating power, each of the plurality of power loads If you need provided, to increase the power consumption of the power load, and a request control unit that transmits the request information in advance power, if it receives the request information from the request control unit, the fuel cell to power load There on condition that it is possible to further supply electric power, the fuel cell control unit that transmits a permission notice indicating that the power consumption may be increased, provided in each of the plurality of power loads, fuel cell controller from the condition that it has received a permission notification to the effect that may increase the power consumption, obtain Preparations and a load control unit to increase the power consumption of the power load.

  When it is necessary to increase the power consumption of the power load, the request control unit transmits the amount of power to be increased to the fuel cell control unit, and the fuel cell control unit is a total value of power required by the plurality of power loads. When the time until the generated power of the fuel cell reaches the time until the plurality of power loads start consuming the total amount of power is temporarily set to the load control unit of the other plurality of power loads. An instruction to reduce the power consumption is given, and then an increase in power consumption is permitted again for some power loads. The load control unit reduces the power consumption of the power load when receiving an instruction to reduce the power consumption from the fuel cell control unit.

Fuel cell control unit transmits the amount of power that reduces the load control unit, when the load control unit, which has received the instruction to reduce the power consumption from the fuel cell controller, only the amount of power to the decrease, the power reducing the power consumption of the load.

  The fuel cell system according to the present embodiment further includes an operation mode table indicating the power consumption of the power load according to the operation mode of the power load, and the load control unit transitions to reduce the power consumption by the amount of power to be reduced. The necessary operation mode is determined with reference to the operation mode table, and the operation mode is changed. For this reason, even if it is a case where electric power runs short, power consumption can be reduced, without stopping completely.

The fuel cell control unit stores the priority of each of the plurality of power loads in advance, and when the request information is received from the request control unit of the power load with a higher priority, the load of the power load with the lower priority Instructs the control unit to reduce power consumption.

The request control unit transmits period information indicating a period for requesting power to the fuel cell control unit. Fuel cell control unit has received from the request control unit, increases the required amount and duration information of the power consumption, and based on the time to initiate the increase in power consumption in each power load, each power load current consumption By reducing the power consumption of one of the lower priority power loads when receiving the new request information from the request control unit of the higher priority power load It is determined whether power according to the new request information can be supplied.

  Since the request control unit transmits period information indicating the period for requesting power to the fuel cell control unit, the fuel cell control unit can know in advance the time when the power consumption of the power load decreases after increasing. For this reason, it is possible to appropriately determine whether or not the power generation amount of the fuel cell should be increased or decreased.

The request control unit refers to the operation mode table to determine the amount of power consumption that needs to be increased compared to the current power consumption when attempting to change the operation mode, and determines the amount of increase required as fuel. Transmit to the battery controller. For this reason, the power generation amount of the fuel cell can be increased in advance by the amount of power consumption required by the power load. The load control unit determines, using the operation mode table, an operation mode in which the transition can be performed within the allowable power consumption range, and transitions to the operation mode. Therefore, the most preferable operation mode can be selected within the allowable power range.

The fuel cell system control method according to still another embodiment of the present invention, when the fuel cell needs to increase power consumption of the plurality of power loads that runs by electric power generated, provided to each of the plurality of power loads and request control step of requesting control unit transmits the request information of the pre-Me power, if the request control unit has received the request information, on condition that the fuel cell to power load can be further supplying power, a fuel cell control step of transmitting a permission notice indicating that the power consumption may be increased, the load control unit provided in each of a plurality of power loads, fuel cell controller or et power consumption increase on condition that received a permission notification may, e Bei a load control step of increasing the power consumption of the power load, the request control step, when there is a need to increase the power consumption of the power load The amount of power to be increased is transmitted, and the fuel cell control step determines that the time until the generated power of the fuel cell reaches the total value of power required by the plurality of power loads If it is longer than the time until the start of power consumption, once instruct the load control unit of the other plurality of power loads to reduce power consumption, and then for some power loads, allow an increase in power consumption again, load control step, when the load control unit is an instruction to reduce the power consumption has been received from the fuel cell controller, thereby reducing the power consumption of the power load.

Buildings in another aspect of the present invention, increasing a fuel cell, a plurality of power loads that runs with power fuel cell is generating power, provided in each of the plurality of power loads, the power consumption of the power load If it is necessary, a request control section to transmit the request information in advance power, if the request control unit has received the request information, on condition that the fuel cell to power load can be further supplied power a fuel cell control unit that transmits a permission notice indicating that the power consumption may be increased, provided in each of the plurality of power loads, permission from the fuel cell controller, to the effect that may increase the power consumption on condition that it has received the notification, e Bei a load control unit to increase the power consumption of the power load, the request control unit, when it is necessary to increase the power consumption of the power load, the magnitude of the power increase Fuel cell controller The fuel cell control unit transmits a time until the generated power of the fuel cell reaches the total value of power required by the plurality of power loads until the plurality of power loads start consuming the power of the total value. If it is longer than the time, once instruct the load control units of other power loads to reduce power consumption, and then allow some power loads to increase power consumption again. , load control unit, when an instruction to reduce power consumption received from the fuel cell controller, thereby reducing the power consumption of the power load.

The fuel cell control unit transmits the power amount to be reduced to the load control unit, and when the load control unit receives an instruction to reduce power consumption from the fuel cell control unit, the power load is reduced by the power amount to be reduced. Reduce the power consumption. Buildings in or this embodiment, corresponding to the operation mode of the power load, the further example Bei operation mode table showing the power consumption of the power load, the load control unit for lowering only the power consumption but the amount of power decrease The operation mode that needs to be changed to is determined with reference to the operation mode table, and the operation mode is changed . Contact summary of the invention, such is not intended to list all the necessary features of the present invention can be a sub-combination of the features also invention.

According to the present invention, the fluctuation speed of power consumption can be kept below a predetermined speed.

FIG. 1 is a diagram showing an example of the configuration of a fuel cell system 30 according to an embodiment of the present invention.
FIG. 2 is a diagram showing an example of the configuration of a heating device 48a.
FIG. 3 is a diagram showing an example of the configuration of a power load 44a.
FIG. 4 is a diagram showing an example of the relationship between generated power and power generation efficiency in a plurality of fuel cells 40.
FIG. 5 is a sequence diagram showing a communication sequence in which the power load 44 requests power.
FIG. 6 is a flowchart showing details of the operation of the fuel cell control unit 50 when power request information is received.
FIG. 7 is a diagram showing an example of a management table managed by the fuel cell control unit 50.
FIG. 8 is a diagram showing an example of time development of generated power generated by the fuel cell 40.
FIG. 9 is a sequence diagram showing an example of a communication sequence when a reduction in power consumption is requested.
FIG. 10 is a flowchart showing details of the operation of the fuel cell control unit 50 when a reduction in power consumption is requested.
FIG. 11 is a diagram showing an example of time development of generated power generated by the fuel cell 40.
FIG. 12 is a diagram showing an example of a consumption pattern of power consumed by the power load 44.
FIG. 13 is a diagram showing an example of time development of power consumed by the power load 44 and the storage battery.
FIG. 14 is a diagram showing an example of the configuration of a power path.
FIG. 15 is a diagram illustrating an example of a configuration of a computer 500 included in each of the fuel cell control unit 50, the request control unit 66, and the load control unit 58.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 40 ... Fuel cell, 42 ... Main hot water tank, 44 ... Electric power load, 46 ... Heat pump, 48 ... Heating device, 50 ... Fuel cell control part, 52 ... Sub hot water tank, 56 ... Operation mode table, 58 ... Load control part , 60 ... Hot water supply history management unit, 62 ... Home determination unit, 66 ... Request control unit, 30 ... Fuel cell system

  Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the claimed invention, and all combinations of features described in the embodiments are inventions. It is not always essential to the development means.

  FIG. 1 is a diagram showing an example of the configuration of a fuel cell system according to an embodiment of the present invention. An object of the present embodiment is to provide a fuel cell system that can appropriately prevent the peak of power consumption from exceeding the maximum power generation amount by the fuel cell.

  The fuel cell system 30 supplies power and heat to an apartment house that is a building including a plurality of houses (110a to 110c, hereinafter collectively referred to as 110), for example. Here, the apartment house may be one in which a plurality of residences 110 are provided in one building, and each of a plurality of buildings provided in different areas may be the residence 110.

  The dwelling 110b and the dwelling 110c have the same components as the dwelling 110a. By identifying the constituent elements of the dwelling 110b and dwelling 110c with the symbols b and c at the end of each constituent element, the dwelling 110 is identified. That is, the fuel cell system 30 includes a plurality of fuel cells (40a to 40c, hereinafter collectively referred to as 40), a plurality of power loads (44a to 44c, hereinafter collectively referred to as 44), and a plurality of heating devices (48a to 48a). 48c, hereinafter collectively referred to as 48), a plurality of main hot water tanks (42a to 42c, hereinafter collectively referred to as 42), a plurality of thermal loads (54a to 54c, hereinafter collectively referred to as 54), and a plurality of hot water supply history management. Part (60a-60c, generically referred to as 60 hereinafter), a plurality of at-home determination units (62a-62c, generically referred to as 62 below), and a single heating device 48d and sub-hot water storage that the residence 110 does not have. A tank 52 and a fuel cell control unit 50 are provided.

  Hereinafter, the operation of each component of the residence 110a will be described. In the present embodiment, the fuel cell 40a is provided in the residence 110a and supplies power to the heating device 48a. Further, the fuel cell 40 a is provided so that power can be supplied to any power load 44. Therefore, when the fuel cell 40a generates power consumed by one power load 44, the fuel cell 40a also supplies power to the other plurality of power loads 44 even when the fuel cell 40a is in partial load operation. By generating electric power, the fuel cell 40a can be driven with higher operation efficiency. Further, even when the fuel cell 40a does not need to supply power, the fuel cell 40a is not stopped and is kept in a hot idling state in which only auxiliary power for generating the operation of the fuel cell 40a itself is generated. When the electric power required by the electric power load 44 increases, electric power can be supplied more quickly than when the fuel cell 40a is activated. Moreover, even if the fuel cell 40 of another residence 110 fails, electric power can be supplied from the fuel cell 40a. Thus, since the fuel cell 40 is provided with two or more, it can respond to the wide fluctuation | variation of load.

  The fuel cell 40a is, for example, a polymer electrolyte fuel cell (PEFC). The fuel cell 40a may be one that reforms city gas, propane gas, or the like supplied to each residence to generate hydrogen gas as fuel, and uses hydrogen gas supplied from the outside as fuel. It may be a thing. The fuel cell 40a includes a battery, and the battery may be used as a power source for causing the fuel cell system 30 to function in an emergency, and may be used as a power source when starting up the fuel cell system 30. Also good.

  The main hot water storage tank 42a stores hot water heated by the heat generated in the fuel cell 40a and hot water heated by the heating device 48a. The main hot water tank 42a supplies heat to the heat load 54a. The sub hot water tank 52 stores hot water heated by the heating device 48d, and supplies hot water to a hot water facility different from the hot water facility in which the main hot water tank 42a supplies hot water.

  The home determination unit 62a determines whether or not the user is at home. The home determination unit 62a detects, for example, the lock information of the lock provided on the door of the residence 110a, and determines that the home is not home when locked from the outside of the residence 110a, or the inside of the residence 110a. If you are locked from the home. Further, the at-home determination unit 62a may detect whether or not the user is at home by detecting a fluctuation amount of power consumption or heat consumption. For example, it may be assumed that the user is at home when the fluctuation amount of power consumption is larger than a predetermined reference amount, and the user is not at home when the fluctuation amount of power consumption is equal to or less than a predetermined reference amount. The home determination unit 62a may include an infrared sensor, and determine whether or not the user is at home by detecting infrared energy emitted from the human body. In this case, the infrared sensor may be a pyroelectric infrared sensor, for example.

  The hot water supply history management unit 60a manages the consumption of hot water and the history of the amount of hot water produced by the fuel cell 40a. In the present embodiment, the hot water supply history management unit 60a detects the amount of hot water supplied from the main hot water tank 42a as the consumption amount of hot water. In addition, the hot water supply history management unit 60a detects the amount of hot water supplied to the main hot water storage tank 42a as the amount of hot water produced by the fuel cell 40a and the heating device 48a. Further, the day is divided into hourly time zones, and the consumption of hot water and the history of the amount of hot water produced in each time zone are managed.

  The hot water supply history management unit 60a may manage the amount and temperature of hot water as the consumption of hot water and the production amount of hot water by the fuel cell 40a and the heating device 48a. That is, a product obtained by multiplying the hot water temperature of the main hot water storage tank 42a by the water supply temperature and the volume of the hot water supplied from the main hot water storage tank 42a is detected as the hot water consumption.

  Further, the temperature of the hot water supplied from the fuel cell 40a to the main hot water tank 42a is subtracted from the temperature before the fuel cell 40a is cooled by the cooling water supplied to the fuel cell 40a. The product of the volume of hot water supplied to 42a may be detected as the amount of hot water produced by the fuel cell 40a. Further, the temperature of the hot water supplied from the warming device 48a to the main hot water tank 42a is subtracted from the temperature of the hot water supplied to the warming device 48a before the temperature of the hot water supplied from the warming device 48a to the main hot water tank 42a. You may detect what multiplied the volume of the warm water supplied to as a production amount of the warm water by the heating device 48a.

  Further, the hot water supply history management unit 60a uses hot water consumption and production when it is determined that the home determination unit 62a is home, and hot water consumption and production when it is determined that it is not home. Each history is managed.

  The power load 44a is operated by the power generated by the fuel cell 40. The power load 44a requests power from the fuel cell control unit 50 before consuming power. The fuel cell control unit 50 increases the generated power of the fuel cell 40 in advance when power is requested from the power load 44a.

  The operation of each component of the dwelling 110a has been described above, but the operation of each component of the dwelling 110b and the dwelling 110c is the same as the operation of each component of the dwelling 110a.

  FIG. 2 is a diagram illustrating an example of the configuration of the heating device 48a. The heating device 48a heats water using surplus power generated by the fuel cell 40a. The heating device 48a is a heat pump 46a that warms water by transferring external heat to water. Since the heat pump 46a warms the water by moving the external heat quantity to the water, a large quantity of heat can be supplied with a small amount of electric power. When the ratio of heat demand to power demand is greater than the ratio of the amount of heat produced by the fuel cell 40a to the power generated by the fuel cell 40a, heat can be efficiently supplied by driving the heat pump 46a using surplus power. . For this reason, the demand amount of electric power and the demand amount of calorie | heat amount can be balanced appropriately.

  Moreover, the heating device 48b of the residence 110b and the heating device 48c of the residence 110c have the same components as the heating device 48a. That is, the heating device 48b and the heating device 48c have a heat pump 46b and a heat pump 46c, respectively. Moreover, since the operation | movement of the heat pump 46b and the heat pump 46c is the same as the heat pump 46a, description is abbreviate | omitted.

  FIG. 3 is a diagram illustrating an example of the configuration of the power load 44a. The power load 44a includes a load unit 64a, an operation mode table 56a, a load control unit 58a, and a request control unit 66a. Moreover, the power load 44b of the residence 110b and the power load 44c of the residence 110c have the same components as the power load 44a. By appending b to the end of the code of each component included in the power load 44b and adding c to the end of the code of each component included in the power load 44c, the component of which power load 44 is identified.

  Hereinafter, the operation of each component of the power load 44a will be described. The load unit 64a consumes power supplied from the fuel cell 40. The operation mode table 56a indicates the power consumption of the power load 44a according to the operation mode of the power load 44a. The operation mode table 56a stores power consumption information in association with the operation mode information. For example, when the power load 44a is a cooling device and has an operation mode of rapid cooling and normal cooling, power consumption required to operate in each operation mode in association with each operation mode of rapid cooling and normal cooling Is stored in the operation mode table 56a.

  The request control unit 66a transmits power request information to the fuel cell control unit 50 in advance when it is necessary to increase the power consumption of the power load 44a. At this time, the power consumption that needs to be increased is determined with reference to the operation mode table 56a, and the required increase amount is transmitted to the fuel cell control unit 50 as power request information. Further, the request control unit 66a transmits period information indicating a period for requesting power and time limit information indicating a time limit for starting power consumption to the fuel cell control unit 50 as power request information. At this time, the request control unit 66a may determine the period information and the time limit information based on an instruction or the like by a user who uses the power load 44a. For example, when the power load 44a is a cooling device, the user of the power load 44a instructs the power load 44a about the target temperature and the target time to reach the target temperature. At this time, the request control unit 66a calculates the power consumption to be increased, the time limit for starting power consumption, and the period for power consumption based on the target temperature, the target time, and the current temperature instructed by the user. Then, each is transmitted to the fuel cell control unit 50 as the power consumption, the time limit information, and the period information of the power request information.

  When receiving the permission notification from the fuel cell control unit 50, the load control unit 58a increases the power consumption of the power load 44a within the allowable range. At this time, the load control unit 58a uses the operation mode table 56a to determine an operation mode that can be changed within the allowable power consumption range, and controls the load unit 64a to change to the operation mode. . The load control unit 58a, the request control unit 66a, and the fuel cell control unit 50 are connected by a communication network such as Ethernet (registered trademark). As another method, a data communication signal between the load control unit 58a, the request control unit 66a, and the fuel cell control unit 50 is modulated to a frequency sufficiently higher than the frequency of the power source and superimposed on the power source line. May be.

  The operation of each component of the power load 44a has been described above, but each component of the power load 44b and the power load 44b operates in the same manner as each component of the power load 44a, and thus description thereof is omitted.

  In the fuel cell system 30 of the present embodiment, when the fuel cell control unit 50 receives the request information from the request control unit 66, the fuel cell control unit 50 determines the amount of increase in power consumption that can be allowed when power can be supplied. The load control unit 58 is notified as a permission notification. The fuel cell control unit 50 transmits a permission notice to the load control unit 58 when the power generation efficiency of the fuel cell 40 can be made higher than a predetermined power generation efficiency.

  FIG. 4 is a diagram illustrating an example of the relationship between the generated power and the power generation efficiency in the plurality of fuel cells 40. In general, the power generation efficiency of the fuel cell 40 depends on the power generated by the fuel cell 40. For this reason, even in a system in which a plurality of fuel cells 40 are connected, the overall power generation efficiency depends on the generated power as shown in FIG. In a system in which a plurality of fuel cells 40 are connected, when the reference efficiency that is the lower limit of the overall power generation efficiency is determined, the total range of the amount of power that the fuel cell 40 should generate is determined. For example, the total power generated by the fuel cell 40 is between the first lower limit power (P1) and the first upper limit power (P2), between the second lower limit power (P3) and the second upper limit power (P4), or If it is either between the third lower limit power (P5) and the third upper limit power (P6), the power generation efficiency is equal to or higher than the reference efficiency.

  Therefore, the fuel cell control unit 50 controls the power generation amount of the plurality of fuel cells 40 so that the sum of the power generated by the plurality of fuel cells 40 is within a predetermined power range. The power generation efficiency can be greater than or equal to a predetermined power generation efficiency. That is, the fuel cell control unit 50 is a case where the required power is less than the maximum generated power that can be generated by the fuel cell 40, and the total amount of power generated by the fuel cell 40 when the required power is generated. However, the fuel cell control unit 50 transmits a permission notice to the load control unit 58 when the power is within a predetermined range of power generation efficiency.

  FIG. 5 is a sequence diagram illustrating a communication sequence in which the power load 44 requests power. The request control unit 66b transmits power request information to the fuel cell control unit 50 when it is necessary to increase the power consumption of the power load 44b (S200).

  The fuel cell control unit 50 makes a request determination based on the power request information from the request control unit 66b (S202). If it is determined in S202 that the output of the fuel cell 40b needs to be increased, the output of the fuel cell 40b is increased (S204). When the output of the fuel cell 40b increases and the preparation for supplying the requested power is completed (S206), a permission notice indicating that the power consumption may be increased is transmitted to the load control unit 58b (S208). When the load control unit 58b receives the permission notification, the load control unit 58b controls the load unit 64b to consume the power amount within the allowable range, so that the power load 44a starts power consumption (S209).

  When it is necessary to increase the power consumption of the power load 44a, the request control unit 66a transmits power request information to the fuel cell control unit 50 (S210). The fuel cell control unit 50 makes a request determination based on the power request information from the request control unit 66a (S212). If it is determined in S212 that the fuel cell 40a needs to be activated, the fuel cell 40a is activated (S214). When the fuel cell 40a is activated and preparation for supplying the requested power is completed (S216), a permission notice indicating that the power consumption may be increased is transmitted to the load control unit 58a (S218). When the load control unit 58a receives the permission notification, the load control unit 58a controls the load unit 64a to consume the power amount within the allowable range, so that the power load 44a starts power consumption (S219).

  FIG. 6 is a flowchart showing details of the operation of the fuel cell control unit 50 when the power request information is received. The fuel cell control unit 50 determines whether power can be supplied for a specified period based on the request information from the request control unit 66 (S230). If power can be supplied, a permission notice is transmitted to the load control unit 58 (S234), and the process ends.

  If power cannot be supplied in S230, whether or not preparation for supplying power with generated power that is higher than the power generation efficiency determined in advance by the consumption start time limit is ready based on the power request information from the request control unit 66 Is determined (S232). When it is ready to supply power in S232, the output of the fuel cell 40 is increased (S236). If it is necessary to start the fuel cell 40 in S236, the fuel cell 40 is started. Further, the fuel cell control unit 50 transmits a conditional permission notice to the load control unit 58 based on the output of the fuel cell 40 (S238). The conditional permission notification transmitted in S238 may include information indicating the time when the fuel cell 40 can supply power and the amount of power. For example, the conditional permission notice when the fuel cell 40 is activated in S236 may include a time when the requested power can be supplied, and also includes an amount of power that can be supplied at the present time. Also good.

  If it is not ready to supply power in S232, it is determined whether or not the power load 44 can be tolerated even if the power is less than the requested power (S240). In S <b> 240, the fuel cell control unit 50 determines whether the power load 44 can be tolerated based on the power request information from the request control unit 66 even if the power is less than the requested power. For example, the request control unit 66 transmits information indicating whether or not the power load 44 can operate with lower power than the requested power to the fuel cell control unit 50 together with the requested power as power request information. Further, the request control unit 66 may refer to the operation mode table 56 and transmit the lower limit power at which the power load 44 can operate as power request information to the fuel cell control unit 50 together with the requested power. Accordingly, the fuel cell control unit 50 determines whether or not the power load 44 can be tolerated even if the power is less than the requested power.

  In S240, if the power load 44 cannot tolerate less power than the requested power, the process of S236 is performed, and a permission notice indicating a conditional determination result or a conditional permission notice is sent to the load control unit 58 in S238. Send and finish the process. The permission notification indicating the conditional determination result transmitted in S238 may include information indicating the time when the fuel cell 40 can supply power and the amount of power. For example, the permission notice indicating the conditional determination result is a time when the fuel cell 40 can start the supply of power when supplying the requested power while generating power with the generated power higher than the predetermined power generation efficiency. It may also include the amount of power that can be supplied at the present time or before the deadline. Further, the conditional permission notification transmitted in S238 may include information indicating the time when the fuel cell 40 can supply power and the amount of power. For example, the conditional permission notice when the fuel cell 40 is started in S236 may include a time when the requested power can be supplied, and also include an amount of power that can be supplied by the present time or before the deadline. It may be.

  If the power load 44 can be tolerated even if the power is less than the power requested in S240, a permission notification indicating a conditional determination result or a conditional permission notification is transmitted to the load control unit 58 in S242, and the process is performed. finish. The permission notification indicating the conditional determination result transmitted in S242 may include information indicating the time when the fuel cell 40 can supply power and the amount of power. For example, the permission notice indicating the conditional determination result is a time when the fuel cell 40 can start the supply of power when supplying the requested power while generating power with the generated power higher than the predetermined power generation efficiency. In addition, the fuel cell 40 may include the amount of power that can be supplied by the present time or before the deadline while generating power with generated power that is higher than a predetermined power generation efficiency. In addition, the conditional permission notification transmitted in S242 may include information indicating the amount of power that the fuel cell 40 can supply. For example, the conditional permission notification may include the amount of power that can be supplied by the present time or before the deadline while the fuel cell 40 generates power with generated power that is higher than a predetermined power generation efficiency.

  When the load control unit 58 receives a permission notification indicating a conditional determination result or a conditional permission notification from the fuel cell control unit 50, the range of allowable power notified by the permission notification. The operation mode that can be changed in the operation mode may be determined from the operation mode table 56 to change to the operation mode. Further, the load control unit 58 may control the load unit 64 to start power consumption at a specified time based on the time when the power can be received notified by the permission notification.

  FIG. 7 is a diagram illustrating an example of a management table managed by the fuel cell control unit 50. In the management table, state information, time information, time limit information, period information, and power information related to the power load 44 are stored in association with the power load 44. In the state information, either a request or consumption state indicating the power consumption state of the power load 44 is stored. The time information stores the time when the supply of power to the power load 44 is started or the time when power is requested from the power load 44. The time limit information stores a time limit for starting power consumption when power is requested from the power load 44. The period information stores a period during which the power load 44 consumes power. In the power information, the power consumed by the power load 44 is stored.

  FIG. 8 is a diagram illustrating an example of time development of the generated power generated by the fuel cell 40. The horizontal axis represents time, and the vertical axis represents the total amount of power generated by the fuel cell 40. When it is necessary to increase the power consumption, the request control unit 66 of the power load 44 supplies the fuel cell control unit 50 with request information indicating that power is consumed at a time (t0) earlier than the time when the power consumption is increased. Send. The request control unit 66 of the power load 44 performs fuel cell control using the time limit (time t1) for starting power consumption, the period for consuming power (the period obtained by subtracting the time t2 and time t1), and the power to be increased as request information. To the unit 50. Based on the request information from the request control unit 66a, the fuel cell control unit 50 performs a specified period of time (a period obtained by subtracting the time t2 and the time t1) until the specified time limit (time t1). To increase the power generated by the fuel cell 40.

  According to the fuel cell system 30 of the present embodiment, when the request control unit 66 needs to increase the power consumption of the power load 44, the power load 44 increases the power consumption because the power request information is transmitted in advance. Before starting, the power generation amount of the fuel cell 40 can be increased in advance. Further, the request control unit 66 refers to the operation mode table 56 to determine the amount of power consumption that needs to be increased compared to the current power consumption when attempting to change the operation mode, and increases the power consumption. Since the required amount is transmitted to the fuel cell control unit 50, the power generation amount of the fuel cell 40 can be increased in advance by the amount of power consumption required by the power load 44. In addition, since the request control unit 66 transmits period information indicating a period for requesting power to the fuel cell control unit 50, the fuel cell control unit 50 determines in advance the time to decrease after the power consumption of the power load 44 increases. I can know. For this reason, it is possible to appropriately determine whether or not the power generation amount of the fuel cell 40 should be increased or decreased.

  Further, since the load control unit 58 increases the power consumption of the power load 44 on the condition that the permission notification that the power consumption may be increased is received from the fuel cell control unit 50, the power consumption of the entire system is increased. The fluctuation of becomes smaller. For this reason, even a relatively small fuel cell 40 can stably supply electric power. Further, since the load control unit 58 increases the power consumption within the allowable range received from the fuel cell control unit 50, even if the power generation amount that can be increased by the fuel cell 40 is small, the load control unit 58 increases the power consumption. The amount of power generation can be used effectively. Further, the load control unit 58 uses the operation mode table 56 to determine an operation mode that can be changed within the allowable power consumption range, and at this time, the operation mode is changed to an operable operation mode. The most preferred mode of operation can be selected within the range of power to be used.

  Furthermore, in the fuel cell system 30 of the present embodiment, the fuel cell control unit 50 determines the power consumption of the other power load 44 in order to increase the power consumption of the other power load 44 at the timing when the power consumption of one power load 44 decreases. A permission notice is transmitted to the load control unit 58. At this time, the fuel cell control unit 50 may receive a notification that the power consumption is reduced from the request control unit 66 in advance, and may increase the power consumption of the other power load 44 when the power consumption of the power load 44 decreases. . As another method, the fuel cell control unit 50 detects that the power consumption of the power load 44 has decreased by decreasing the output voltage or output current, and in that case A permission notice may be sent. Thereby, the fluctuation | variation of the power consumption of the whole system can be made small. For this reason, the fluctuation | variation of the electric power generation amount by the fuel cell 40 becomes small, and the loss of the energy which arises when changing an electric power generation amount can be reduced by extension. Further, the fuel cell 40 can be continuously driven with high efficiency.

  For example, the power consumption may change in a time of about 10 milliseconds, but generally a time of about several hundred milliseconds is required to change the amount of power generated by the fuel cell 40. Therefore, if the generated power of the fuel cell 40 is changed, the power generated until the generated power value of the fuel cell 40 reaches the demand power value is wasted. That is, when the power generated by the fuel cell 40 is increased in order to cope with the increase in power consumption of the power load 44, the power generated by the fuel cell 40 is until the power required by the power load 44 is reached. Since the power load 44 cannot effectively consume the power, the power generated by the fuel cell 40 during that time is wasted. Further, when the power generated by the fuel cell 40 is reduced in order to cope with the reduction in the power consumption of the power load 44, the power generated by the fuel cell 40 is generated until the reduced power consumption is reached. Electricity is wasted without being consumed. In addition, when it is necessary to newly start the fuel cell 40 in accordance with fluctuations in power demand, the energy for raising the temperature of the reformer before the fuel cell 40 having the reformer is started from the stop state. is required. Therefore, if the variation in the amount of power generated by the fuel cell 40 is large, energy is wasted. On the other hand, according to the present embodiment, it is possible to reduce the fluctuation in the amount of power generated by the fuel cell 40 while controlling the fuel cell 40 so as to exceed a predetermined power generation efficiency. The fuel cell 40 can be operated in this state.

  In addition, the fuel cell control unit 50 calculates in advance the time when the power consumption of the power load 44 decreases based on the period information received from the request control unit 66, and indicates that the power consumption may be increased at this time. The notification is transmitted to the load control unit 58 of the other power load 44. Further, when the fuel cell control unit 50 receives the power request information and the period information from the plurality of request control units 66, the fuel cell control unit 50 schedules the timing at which the power load 44 increases the power consumption so that the fluctuation of the output power becomes small. Then, the permission notification is transmitted to the load control unit 58 so that each power load 44 increases the power consumption at the scheduled timing. At this time, the fuel cell control unit 50 notifies the load control unit 58 of information indicating the time at which power can be supplied to the power load 44.

  For example, the fuel cell control unit 50 associates the amount of power consumed by the power load 44, the start time of power consumption, and the power consumption period with the power load 44 based on the power request information received from the request control unit 66. Manage. Thereby, since the time when the power consumption of the power load 44 decreases can be calculated in advance, the fuel cell control unit 50 schedules the timing for increasing the power consumption of the power load 44 so that the fluctuation of the output power becomes small. it can. Information indicating the time to start power consumption is transmitted to the load control unit 58 together with the permission notice so that each power load 44 increases the power consumption at the scheduled timing.

  In this way, the fuel cell control unit 50 can control the load to continuously consume power. For this reason, the fluctuation | variation of the power consumption of the fuel cell system 30 whole becomes small. Moreover, since the load whose power consumption approximates can be operated continuously, the fluctuation of the power consumption of the entire fuel cell system 30 is further reduced.

  Also, the fuel cell control unit 50 uses the heating device 48 to heat the water by using the heating device 48 until the power consumption of the power load 44 increases after the permission notification is transmitted to the load control unit 58. To do. In addition, the fuel cell control unit 50 starts up the fuel cell 40 and consumes power by using the heating device 48 until the power can be actually supplied to the power load 44 to heat the water. It's okay. Thereby, even when the response of the power load 44 is slow, it is possible to prevent the power consumption of the entire fuel cell system 30 from fluctuating during that time.

  Furthermore, in the fuel cell system 30 of the present embodiment, the fuel cell control unit 50 needs to reduce the power consumption of the power load 44 in order to maintain the total power consumption value smaller than the maximum power generation amount of the fuel cell 40. In this case, the load control unit 58 is instructed to reduce power consumption.

  For example, normally, when the power consumption exceeds the maximum power generation amount, the power supply is cut off by the current limiter, and the stability of the power supply system is maintained. On the other hand, in the fuel cell system 30 of the present embodiment, when it is determined in advance based on the request information from the power load 44 that the power consumption exceeds the maximum power generation amount, the fuel cell control unit 50 causes the power consumption to be the maximum power generation. By requesting the power load 44 to reduce power consumption so as not to exceed the amount, the stability of the power supply system is maintained.

  When the load control unit 58 receives an instruction to reduce power consumption from the fuel cell control unit 50, the load control unit 58 reduces power consumption. At this time, the load control unit 58 reduces the power consumption by the required power. In addition, the load control unit 58 determines an operation mode that needs to be changed in order to reduce the power consumption by the requested power, with reference to the operation mode table 56, and makes a transition to the operation mode. Thereby, even if it is a case where electric power runs short, power consumption can be reduced, without stopping completely. In this way, it is possible to appropriately prevent the peak of the total value of power consumption from exceeding the maximum power generation amount by the fuel cell 40.

  Furthermore, in the fuel cell system 30 of the present embodiment, the fuel cell control unit 50 reduces the number of fuel cells 40 that are driven to maintain the power generation efficiency of the fuel cell 40 higher than a predetermined power generation efficiency. When necessary, the load control unit 58 is instructed to reduce the power consumption in order to reduce the power consumption of the power load 44.

  For example, when the power consumption of the power load 44 decreases and the power generation efficiency of a certain fuel cell 40 needs to be stopped in order to maintain the power generation efficiency higher than a predetermined power generation efficiency, the total power generation amount with respect to the power consumption May be insufficient. In this case, by instructing the load control unit 66 to reduce the power consumption in advance, the power consumption is controlled so that the power generation amount does not become insufficient, and the power generation efficiency is maintained higher than the predetermined power generation efficiency. be able to.

  FIG. 9 is a sequence diagram illustrating an example of a communication sequence when a reduction in power consumption is requested. The request control unit 66b transmits power request information to the fuel cell control unit 50 in order to increase the power consumption of the power load 44b (S250).

  The fuel cell control unit 50 makes a request determination based on the power request information from the request control unit 66b (S252). If it is determined in S252 that the power consumption of the power load 44a needs to be reduced, the load control unit 58a is instructed to reduce the power consumption of the power load 44a (S254). At this time, the fuel cell control unit 50 transmits information indicating the amount of power to be reduced to the load control unit 58a. When the load control unit 58a receives an instruction to reduce the power consumption from the fuel cell control unit 50, the load control unit 58a controls the load unit 64a so as to reduce the specified amount of power, thereby reducing the power consumption of the power load 44a. (S255). At this time, the load control unit 58a may refer to the operation mode table 56a, select an operation mode that can operate even when power consumption is reduced, and control the power load 44a to transition to the operation mode. When the power consumption of the power load 44a is reduced, and the preparation for supplying the power required by the power load 44b is completed, the fuel cell control unit 50 performs load control with a permission notification indicating that the power consumption may be increased. The data is transmitted to the unit 58b (S256). When receiving the permission notification, the load control unit 58b controls the load unit 64b so that the power load 44b starts power consumption (S258).

  FIG. 10 is a flowchart showing details of the operation of the fuel cell control unit 50 when a reduction in power consumption is requested. Based on the request information from the request control unit 66b, the fuel cell control unit 50 determines whether or not the maximum power generation amount is exceeded when the power requested by the request control unit 66b is supplied (S260). If the maximum power generation amount is exceeded, the load control unit 58a is instructed to reduce the power consumption of the power load 44a so as not to exceed the maximum power generation amount in order to reduce the power consumption of the power load 44a currently supplied (S264). . When the power consumption of the power load 44a decreases and the preparation for supplying the power required by the power load 44b is completed, a permission notification indicating that the power consumption may be increased is transmitted (S266).

  If the maximum power generation amount is not exceeded when the power requested by the request control unit 66b is supplied in S260, it is determined whether the fuel cell 40 can be operated with an efficiency higher than a predetermined power generation efficiency (S262). . If the fuel cell 40 can be operated at an efficiency higher than the predetermined power generation efficiency, it is determined whether the fuel cell 40 is ready to supply power (S268). When the fuel cell 40 is ready to supply power, the process proceeds to S266. In S268, when the fuel cell 40 is not ready to supply power, the process of S268 is executed until the preparation is completed. In S262, when the fuel cell 40 cannot be operated with an efficiency higher than the predetermined power generation efficiency, the process proceeds to S264.

  In S264, the priority order of the power load 44a and the power load 44b may be determined, and control may be performed to instruct the load control unit 58a to reduce the power consumption when the priority order of the power load 44a is low. When the priority of the power load 44b is lower than that of the power load 44a, a notice of disapproval may be transmitted to the power load 44b.

  FIG. 11 is a diagram illustrating an example of the time evolution of the generated power generated by the fuel cell 40. When the fuel cell 40 is operating at the maximum power generation amount, the fuel cell control unit 50 causes the power load 44a to reduce the power requested from the power load 44b when requested by the power load 44b. Control is performed so that the power load 44b consumes the reduced power. Alternatively, in order to keep the power generation amount generated by the fuel cell 40 constant over time, the fuel cell control unit 50 instructs to reduce the power consumption of the power load 44a having a low priority, and the reduced power is Control is performed so that the power load 44b having a higher priority is consumed.

  In addition, when the power consumption of the power load 44 increases faster than a predetermined speed, the fuel cell control unit 50 temporarily reduces the power consumption with respect to the load control units 58 of the other plurality of power loads 44. , And after that, a part of the power load 44 is allowed to increase the power consumption again.

  For example, the power consumption may normally change in a time of about 10 milliseconds, whereas the load responsiveness of the fuel cell 40 is generally several hundred milliseconds, so it may not be possible to respond immediately to power demand. . In such a case, by temporarily instructing the load control units 58 of the other plurality of power loads 44 to reduce the power consumption, the power consumption fluctuation speed is kept below a predetermined speed. When the necessary power can be supplied, the power load 44 instructed to reduce the power consumption is allowed to increase the power consumption again.

  In addition, the fuel cell control unit 50 stores the priority of each of the plurality of power loads 44 in advance, and when the request information is received from the request control unit 66 of the power load 44 having a high priority, It instructs the load control unit 58 of the lower power load 44 to reduce power consumption. Further, the fuel cell control unit 50 determines each power load based on the required amount and period information of power consumption received from each request control unit 66 and the time when each power load 44 starts to increase power consumption. 44 determines the amount of power that is currently consumed, and when new request information is received from the request control unit 66 of the power load 44 having a higher priority, one of the power loads 44 having a lower priority. It is determined whether or not power corresponding to new request information can be supplied by reducing the power consumption.

  For example, the fuel cell control unit 50 manages the time when the increase in power consumption is started, the period during which power is consumed, and the power consumption amount for a plurality of power loads 44 that are permitted to consume power. The magnitude of the power consumed by the plurality of power loads 44 at an arbitrary time can be determined. Therefore, when new request information is received from the power load 44 having a high priority, power corresponding to the new request information is supplied by reducing the power consumption of any power load 44 having a low priority. Can be determined.

  Another modified example of the fuel cell system is a system in which the fuel cell 40 in the above embodiment is a device that simultaneously generates power and supplies heat using fossil fuel or hydrogen gas as fuel. Such equipment is, for example, a gas engine or a gas turbine. Also in this modification, it is clear that the same effect as the effect described in the above embodiment can be obtained.

  In still another modified example of the fuel cell system, the request control unit 66 of the power load 44 requests the fuel cell control unit 50 for power required for the power load 44 to perform a target series of operations. At this time, the fuel cell control unit 50 indicates that the power may be consumed by the load control unit 58 when the fuel cell 40 can supply the power necessary for performing the intended operation of the power load 44. Send notifications. The power load 44 stores in advance a power consumption pattern necessary for performing a target operation as a power value for each period and each period.

FIG. 12 is a diagram illustrating an example of a consumption pattern of power consumed by the power load 44. In the consumption pattern 1 shown in FIG. 12 , the power load 44 consumes power of w2 during the period from time u0 to time u1, with u0 as the reference time. Further, the power consumption is changed at time u1, and the power of w4 is consumed for the period up to time u2. Further, in the consumption pattern 2, the power load 44 consumes power of w3 during a period from time u3 to time u4 with u3 as a reference time. Further, the power consumption is changed at time u4, and power w1 is consumed until time u5. The power load 44 may store the power consumption pattern in each operation mode in the operation mode table 56. In addition, when the power load 44 can perform some operations and other operations at intervals in order to perform a target operation, a plurality of consumptions for performing the target operation are performed. A pattern may be stored. For example, as illustrated in FIG. 12 , when some operations and other operations consume power indicated by the consumption pattern 1 and the consumption pattern 2 in order to perform a target operation, When the operation and the other operation can be performed at intervals, the consumption pattern 1 and the consumption pattern 2 may be stored.

  When the power load 44 performs a target operation, the request control unit 66 selects a consumption pattern necessary for the target operation, and transmits request information indicating the power consumption pattern to the fuel cell control unit 50 in advance. To do. In addition, the request control unit 66 transmits a time limit until the start of power consumption indicated by the consumption pattern to the fuel cell control unit 50. When the fuel cell control unit 50 receives the request information from the plurality of request control units 66, the fuel cell control unit 50 follows the power consumption pattern indicated by the request information based on the power consumption for each period indicated by the request information. When the supply of power is started by the requested deadline, the total amount of power consumed by the power load 44 exceeds the maximum amount of power that can be supplied by the fuel cell 40 at any time indicated by the request information. Determine whether or not. When the total amount of power consumed by the power load 44 does not exceed the maximum amount of power that can be supplied by the fuel cell 40 at any time, the fuel cell control unit 50 starts consuming the power indicated by the consumption pattern. Determine the time of day. Further, the fuel cell control unit 50 transmits a permission notification indicating the time at which power consumption is started to the load control unit 58. When the total value of the power consumed by the power load 44 exceeds the maximum amount of power that can be supplied by the fuel cell 40 at any time, the fuel cell control unit 50 does not transmit a permission notice to the load control unit 58. .

  The load control unit 58 starts power consumption on condition that the permission notification is received from the fuel cell control unit 50. At this time, the consumption of power indicated by the consumption pattern is started at the time when the consumption of power received from the fuel cell control unit 50 is started. In this way, the power load 44 can consume power for performing the intended operation.

  In addition, when the power load 44 can perform a part of the operation and another operation in order to perform the target operation, the request control unit 66 performs the part of the operation. Request information indicating a power consumption pattern necessary for the operation and request information indicating a power consumption pattern necessary for performing another operation are transmitted to the fuel cell control unit 50. Further, the request control unit 66 transmits to the fuel cell control unit 50 a time limit until the start of power consumption indicated by each consumption pattern. When the fuel cell control unit 50 newly receives request information indicating a plurality of consumption patterns from the request control unit 66, the fuel cell control unit 50 performs the period indicated by the request information based on the request information already received from the request control unit 66. Calculate the power consumption. Further, the fuel cell control unit 50 is consumed at any time when the supply of power is started in accordance with a plurality of consumption patterns indicated by the new request information by the time limit for starting the consumption of power. The time at which power consumption indicated by each consumption pattern is started is determined so that the total power value does not exceed the maximum amount of power that can be supplied by the fuel cell 40. Furthermore, the fuel cell control unit 50 transmits a permission notification indicating the time at which power consumption indicated by each consumption pattern can be started to the load control unit 58.

  In this way, the power load 44 consumes the amount of power required for each of a part of the operations that can be executed at intervals and the other operations in the time zone in which the fuel cell 40 can supply, thereby achieving the purpose. Can be performed.

  According to such a modification of the fuel cell system, it is possible to prevent the operation from being stopped due to a shortage of power generated by the fuel cell 40 during the period when the power load 44 performs the intended operation.

  In yet another modification of the fuel cell system, the fuel cell system 30 further includes a storage battery that accumulates electric power generated by the fuel cell 40 and supplies electric power to the electric power load 44. The apartment house may include one storage battery, and each of the plurality of residences 110 may include a storage battery. Each fuel cell 40 may include a storage battery. When the fuel cell control unit 50 receives the request information from the request control unit 66 of the power load 44 and the fuel cell 40 cannot supply the requested amount of power, the storage battery determines the amount of power that the fuel cell 40 cannot supply. A permission notice is transmitted to the load control unit 58 on the condition that it can be supplied.

  Further, when the fuel cell control unit 50 cannot supply the amount of power required by the power load 44 by the time limit requested by the request control unit 66, the storage battery can supply the power from the fuel cell 40. Control is performed so that the power is supplied from the storage battery until the fuel cell 40 can supply power, on condition that the amount of power can be supplied within the time limit. Further, the fuel cell control unit 50 transmits a permission notification indicating that power may be consumed to the load control unit 58.

  Further, the storage battery includes a request control unit 66 and a load control unit 58, and transmits request information to request power to the fuel cell control unit 50 when the storage amount stored in the storage battery is lower than a predetermined storage amount. . At this time, the amount of electric power necessary for charging the storage battery is transmitted to the fuel cell control unit 50. When the fuel cell control unit 50 receives the request information from the storage battery request control unit 66, the fuel cell control unit 50 receives the amount of power consumed by the power load 44 and the period during which the power is consumed, received from the request control unit 66 of the power load 44. Thus, the time when the power consumption of the power load 44 decreases is determined, and it is determined at which time the power for charging is supplied to the storage battery. That is, the fuel cell control unit 50 transmits a permission notice for charging the storage battery at the time when the power consumption of the power load 44 decreases. In addition, when the fuel cell control unit 50 receives the request information from the storage battery request control unit 66, the fuel cell control unit 50 receives the amount of power consumed by the power load 44 and the period during which the power is consumed, received from the request control unit 66 of the power load 44. The power generation efficiency of the fuel cell 40 is determined based on the predetermined efficiency by determining the time when the power consumed by the power load 44 decreases and charging the storage battery at the time when the power consumed by the power load 44 decreases. When it becomes high, the permission notification that power is supplied to the storage battery is transmitted to the load control unit 58 of the storage battery. By such control, it is possible to schedule the electric power generated by the fuel cell 40 to be substantially constant in time, so that the fuel cell 40 can be operated efficiently. Further, the fuel cell 40 can be operated with higher efficiency than the predetermined efficiency.

FIG. 13 is a diagram illustrating an example of time evolution of power consumed by the power load 44 and the storage battery. The power load 44c consumes power P7 at time u6. The total amount P8 of the amount of power consumed by the power load 44b and the power load 44c at the time u6 is the maximum value of the amount of power that can be generated by the fuel cell 40. The power load 44b temporarily stops the power consumption at a time u7 after the time u6, and resumes the consumption of the same amount of power as the power consumed at the time u7 from the subsequent time u9. Is scheduled. The power load 44a requests the same amount of power as the power consumed by the power load 44b at the time u6 with the time u6 as the deadline. In this case, the fuel cell 40 cannot supply power to the power load 44a at least during the period from time u6 to time u7. At this time, the fuel cell control unit 50 controls to supply power from the storage battery to the power load 44a. Further, the fuel cell control unit 50 sets a time at which discharge is started at time u6 so that the amount of power discharged from the storage battery is minimized, and loads a permission notice indicating that power consumption starts from time u6. It transmits to the control part 58a.

  In addition, the fuel cell control unit 50 is scheduled in advance so that the power load 44a ends the consumption of power at time u8 before time u9 based on the request information received from the request control unit 66a. From time to time u9, a permission notice indicating that power may be consumed is transmitted to the load control unit 58 of the storage battery so as to charge the storage battery. In this way, the amount of power generated by the fuel cell 40 is maintained substantially constant at the power P8.

  According to such a modification of the fuel cell system, even when the fuel cell 40 cannot supply the power required by the power load 44, the power load 44 operates by supplying power from the storage battery. Can do. Further, since the fuel cell control unit 50 can determine in advance whether or not the storage battery can supply the power required by the power load 44, the power load 44 can be prevented from consuming the power of the storage battery unnecessarily. Further, since the fuel cell control unit 50 controls the time for supplying power from the storage battery to the power load 44 so that the total amount of power supplied from the storage battery to the power load 44 is minimized, the capacity of the storage battery is reduced. be able to.

  In still another modification of the fuel cell system, when the fuel cell control unit 50 receives the request information, the fuel cell 40 is configured so that the power transmission loss in the power path from the fuel cell 40 to the power load 44 is minimized. Determine the amount of power to be generated.

FIG. 14 is a diagram illustrating an example of the configuration of the power path. The fuel cell 40 and the power load 44 are each connected to a power line 74. The power relay device 76 connects a plurality of power lines 74. The power relay device 76 transmits power between the plurality of connected power lines 74. A power path is formed by the power line 74 and the power relay device 76 so that power can be supplied from the fuel cell 40 to any power load 44. The power relay device 76 connects a plurality of power lines 74, such as a transformer. The power relay device 76 connects power lines 74 having different power loss rates.

  The fuel cell control unit 50 stores in advance position information on the power path of the fuel cell 40 and the power relay device 76. That is, the fuel cell control unit 50 stores information for identifying the power line 74 connected to each fuel cell 40 in association with the fuel cell 40. Further, the fuel cell control unit 50 stores information for identifying all the power lines 74 connected to the power relay device 76 and the power loss rate in the power relay device 76 in association with the power relay device 76. The fuel cell control unit 50 further stores the power loss rate in all the power lines 74 in association with the power lines 74.

  In this way, the fuel cell control unit 50 stores the positional information on the power path of the fuel cell 40 and the power relay device 76 in advance, so that when the power line 74 connected to the power load 44 is given, the fuel cell control unit 50 The power path from 40 to the power load 44 can be known. For example, in a route search of a car navigation system, as is well known, a route from a starting point to a destination based on node information indicating a road-to-road connection point and link information indicating a road connecting each node. Search for. Similarly, the fuel cell control unit 50 traces the power path from the fuel cell 40 (departure point) to the power load 44 (destination) through the power relay device 76 (node) and the power line 74 (link) stored in advance. You can search with Further, the fuel cell control unit 50 can calculate the amount of power transmission loss from the power loss rate in the power line 74 and the power relay device 76 on the retrieved power path and the amount of power to be transmitted.

  The power load 44 stores information for identifying the power line 74 to which the power load 44 is connected as position information on its power path. When the power consumed by the power load 44 is increased, the request control unit 66 transmits, to the fuel cell control unit 50, positional information on the power path of the power load 44 together with request information indicating the amount of power consumed. . When the fuel cell control unit 50 receives the request information and the position information of the power load 44 from the request control unit 66, the fuel cell control unit 50 searches each fuel cell 40 for a power path for supplying power to the power load 44, and The power loss rate in the power path is calculated by determining the power line 74 and the power relay device 76 that form the power line. The fuel cell control unit 50 calculates the amount of power transmission loss in the power path based on the power loss rate in the power path and the increase amount of power received from the request control unit 66. The fuel cell control unit 50 increases the amount of power generated by the plurality of fuel cells 40 so that the total amount of power transmission loss on the power path is minimized.

  Further, when the fuel cell control unit 50 receives the request information and the position information indicating the position of the power load 44 on the power path from the request control unit 66, the fuel cell control unit 50 and the power path requested from the request control unit 66 The electric power generated by the fuel cell 40 is increased by the total amount with the upper power transmission loss.

  Further, when there are a plurality of power paths for supplying power from the fuel cell 40 to the power load 44, the fuel cell control unit 50 calculates a power transmission loss when power is transmitted using each power path, Select the power path that minimizes the loss. For example, when power is transmitted over a long distance, when power transmission loss can be minimized by transmitting power using a high-voltage power path, power is transmitted using a high-voltage path.

  According to such a modification of the fuel cell system, the power transmission loss from the fuel cell 40 to the power load 44 can be reduced. In addition, it is possible to prevent the amount of power received by the power load 44 from being insufficient due to power transmission loss.

  FIG. 15 is a diagram illustrating an example of a configuration of a computer 500 included in each of the fuel cell control unit 50, the request control unit 66, and the load control unit 58. In this example, the computer 500 stores a program that causes the fuel cell system to function as the fuel cell system 30 described with reference to FIGS.

  The computer 500 includes a CPU 700, a ROM 702, a RAM 704, a communication interface 706, a hard disk drive 710, a flexible disk drive 712, and a CD-ROM drive 714. The CPU 700 operates based on programs stored in the ROM 702, the RAM 704, the hard disk drive 710, the flexible disk 720, and / or the CD-ROM 722.

  For example, a program for causing the fuel cell system 30 to function causes the computer 500 to function as the fuel cell control unit 50, the request control unit 66, and the load control unit 58 described with reference to FIGS. To work. Further, the computer 500 included in each of the fuel cell control unit 50, the request control unit 66, and the load control unit 58 causes the corresponding fuel cell control unit 50, the request control unit 66, and the load control unit 58 to function. May be stored.

  The communication interface 706 communicates with, for example, the fuel cell 40, the power load 44, the heating device 48, the heat load 54, the main hot water tank 42, the hot water supply history management unit 60, the home determination unit 62, and the sub hot water tank 52, and It receives information about the state and transmits a control signal for controlling each. The hard disk drive 710, the ROM 702, or the RAM 704 as an example of a storage device stores setting information, a program for operating the CPU 700, and the like. The program may be stored in a recording medium such as the flexible disk 720 and the CD-ROM 722.

  When the flexible disk 720 stores a program, the flexible disk drive 712 reads the program from the flexible disk 720 and provides it to the CPU 700. When the CD-ROM 722 stores a program, the CD-ROM drive 714 reads the program from the CD-ROM 722 and provides it to the CPU 700.

  Further, the program may be read directly from the recording medium into the RAM and executed, or once installed in the hard disk drive 710, the program may be read into the RAM 704 and executed. Further, the program may be stored in a single recording medium or a plurality of recording media. The program stored in the recording medium may provide each function in cooperation with the operating system. For example, the program may request the operating system to perform a part or all of the function and provide the function based on a response from the operating system.

  As a recording medium for storing the program, in addition to a flexible disk and a CD-ROM, an optical recording medium such as DVD and PD, a magneto-optical recording medium such as MD, a tape medium, a magnetic recording medium, a flash memory, an IC card, A semiconductor memory such as a miniature card can be used. A storage device such as a hard disk or RAN provided in a server system connected to a dedicated communication network or the Internet may be used as a recording medium.

  As is clear from the above description, according to the present embodiment, the request control unit 66 transmits power request information in advance when it is necessary to increase the power consumption of the power load 44. The power generation amount of the fuel cell 40 can be increased in advance. Further, since the load control unit 58 increases the power consumption of the power load 44 on the condition that the permission notification indicating that the power consumption may be increased is received from the fuel cell control unit 50, the fluctuation of the power consumption of the entire system Becomes smaller. Further, when the load control unit 58 receives an instruction to reduce power consumption from the fuel cell control unit 50, the load control unit 58 reduces power consumption, so that the peak of the total value of power consumption exceeds the maximum power generation amount by the fuel cell 40. Can be prevented appropriately.

  When the power control is insufficient because the load control unit 58 determines the operation mode that needs to be changed in order to reduce the power consumption by the required power with reference to the operation mode table 56 and makes a transition to the operation mode. Even so, it is possible to propose power consumption without completely stopping.

  Since the request control unit 66 transmits period information indicating a period for requesting power to the fuel cell control unit 50, the fuel cell control unit 50 can know in advance the time when the power consumption of the power load 44 decreases after increasing. it can. For this reason, it is possible to appropriately determine whether or not the power generation amount of the fuel cell 40 should be increased or decreased. The request control unit 66 determines the amount of power consumption that needs to be increased compared to the current power consumption when changing the operation mode with reference to the operation mode table 56, and determines the required increase amount. Since the data is transmitted to the fuel cell control unit 50, the power generation amount of the fuel cell 40 can be increased in advance by the amount of power consumption required by the power load 44.

  Since a plurality of fuel cells 40 are provided, it is possible to cope with a wide variation in load. In addition, when the power consumption of the power load 44 increases faster than a predetermined speed, the fuel cell control unit 50 instructs the load control units 58 of the other plurality of power loads 44 to reduce the power consumption. Then, since the increase in power consumption is permitted again for some of the power loads 44, even if the power consumption of the entire fuel cell system 30 suddenly increases, the power consumption can be reduced in a short time. can do.

  The load control unit 58 uses the operation mode table 56 to determine an operation mode that can be changed within the allowable power consumption range, and changes to the operation mode. Therefore, within the allowable power range, The most preferred operating mode can be selected.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements are also included in the technical scope of the present invention.

Claims (13)

A fuel cell;
A plurality of power loads that runs with power the fuel cell is generating power,
Provided in each of the plurality of power loads, when there is a need to increase the power consumption of the previous SL power load, and a request control unit that transmits the request information in advance power,
When the request information is received from the request control unit, a permission notice indicating that the power consumption may be increased is transmitted on condition that the fuel cell can further supply power to the power load. A fuel cell control unit;
Provided in each of the plurality of the power load, before Symbol fuel cell controller, on condition that it has received a permission notification to the effect that may increase the power consumption, the load control unit to increase the power consumption of the power load And
The request control unit, when it is necessary to increase the power consumption of the power load, transmits the amount of power to be increased to the fuel cell control unit,
The fuel cell control unit waits until the power generated by the fuel cell reaches the total value of power required by the plurality of power loads until the plurality of power loads start consuming the total value of power. in the case of longer than the time temporarily performs an instruction to reduce the power consumption for the previous SL load control unit of the other of the plurality of power loads, for subsequent part of the power load, power consumption again Allow an increase in
The load control unit, when an instruction to reduce power consumption received from the fuel cell controller, the fuel cell system to reduce the power consumption of the power load. The fuel cell control unit transmits an amount of power to be reduced to the load control unit,
Before SL load control unit, when receiving an instruction to reduce power consumption from the fuel cell controller, only the amount of power to the reduction, according to claim 1 for reducing the power consumption of the power load Fuel cell system. An operation mode table indicating the power consumption of the power load according to the operation mode of the power load;
The load control unit, the operation mode that needs to transition to lower the only power consumption but the amount of power to the decrease, it is determined by referring to the operation mode table, according to claim 2 for transitioning to the operating mode Fuel cell system. The fuel cell control unit stores in advance the priority of each of the plurality of power loads, and when the request information is received from the request control unit of the power load having a high priority, The fuel cell system according to claim 1, wherein an instruction to reduce power consumption is given to the load control unit of the low power load. The request control unit transmits period information indicating a period for requesting power to the fuel cell control unit,
The fuel cell control unit determines whether each power load is received based on the required amount and period information of power consumption received from each request control unit and the time when each power load starts to increase power consumption. When determining the amount of power currently consumed and receiving new request information from the request control unit of the power load with higher priority, consumption of any of the power loads with lower priority The fuel cell system according to claim 4, wherein it is determined whether power corresponding to new request information can be supplied by reducing power. The request control unit refers to the operation mode table to determine the amount of power consumption that needs to be increased compared to the current power consumption when attempting to change the operation mode, and the required increase amount The fuel cell system according to claim 3, wherein the fuel cell control unit is transmitted to the fuel cell controller. 4. The fuel cell system according to claim 3, wherein the load control unit determines, using the operation mode table, an operation mode capable of transitioning within a range of allowable power consumption, and transitions to the operation mode. If the fuel cell is required to increase the power consumption of a plurality of power loads that runs by electric power generated, request control unit provided in each of the plurality of power loads the request information in advance power A request control step to send;
Indicates that when the request information is received from the request control unit, the fuel cell control unit may increase power consumption on condition that the fuel cell can further supply power to the power load. A fuel cell control step for sending a permission notice;
Load control unit provided in each of a plurality of the power load, on condition that it has received a permission notification to the effect that may increase the previous SL fuel cell controller or et power consumption, the power consumption of the power load And a load control step for increasing
In the request control step, when it is necessary to increase the power consumption of the power load, the amount of power to be increased is transmitted,
In the fuel cell control step, the time until the generated power of the fuel cell reaches the total value of power required by the plurality of power loads until the plurality of power loads start consuming the power of the total value. If the time is longer than the time, the instruction to lower the power consumption is once given to the load control units of the other plurality of power loads, and then the power consumption is re-applied to some of the power loads. Allow increase,
The load control step, when said load control unit has received an instruction for lowering the power consumption from the fuel cell controller, the fuel cell system control method for reducing the power consumption of the power load.   The fuel cell control step transmits an amount of power to be reduced to the load control unit,
  The load control step reduces the power consumption of the power load by the amount of power to be reduced when the load control unit receives an instruction from the fuel cell control unit to reduce the power consumption. The fuel cell system control method described. A step of managing an operation mode table indicating power consumption of the power load according to the operation mode of the power load;
The load control step, the operation mode that needs to transition to lower the only power consumption but the amount of power to the decrease, it is determined by referring to the operation mode table, according to claim 9 for the transition to the operating mode Fuel cell system control method. A fuel cell;
A plurality of power loads that runs with power the fuel cell is generating power,
Provided in each of the plurality of power loads, when there is a need to increase the power consumption of the previous SL power load, and a request control unit that transmits the request information in advance power,
When the request information is received from the request control unit, a permission notice indicating that the power consumption may be increased is transmitted on condition that the fuel cell can further supply power to the power load. A fuel cell control unit;
Provided in each of the plurality of the power load, before Symbol fuel cell controller, on condition that it has received a permission notification to the effect that may increase the power consumption, the load control unit to increase the power consumption of the power load And
The request control unit, when it is necessary to increase the power consumption of the power load, transmits the amount of power to be increased to the fuel cell control unit,
The fuel cell control unit waits until the power generated by the fuel cell reaches the total value of power required by the plurality of power loads until the plurality of power loads start consuming the total value of power. If the time is longer than the time, the instruction to lower the power consumption is once given to the load control units of the other plurality of power loads, and then the power consumption is re-applied to some of the power loads. Allow increase,
The load control unit, when an instruction to reduce power consumption received from the fuel cell controller, building to reduce the power consumption of the power load.   The fuel cell control unit transmits an amount of power to be reduced to the load control unit,
  The building according to claim 11, wherein when the load control unit receives an instruction to reduce power consumption from the fuel cell control unit, the load control unit reduces power consumption of the power load by the amount of power to be reduced. An operation mode table indicating the power consumption of the power load according to the operation mode of the power load;
The load control unit, the operation mode that needs to transition to lower the only power consumption but the amount of power to the decrease, it is determined by referring to the operation mode table, according to claim 12 to transition to the operation mode Building.

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