JP5922524B2 - Control device, fuel cell unit and control method - Google Patents

Description

  The present invention relates to a control device, a fuel cell unit, and a control method for controlling a fuel cell unit including a power generation unit and auxiliary equipment.

  In recent years, a fuel cell unit including a power generation unit that generates power by a chemical reaction and an auxiliary device that assists the operation of the power generation unit is known (for example, Patent Document 1). In normal operation, the output power (generated power) of the fuel cell unit is controlled to follow the power consumption of the load provided on the power line connecting the system and the fuel cell unit (load following control).

  By the way, as an operation mode of the fuel cell unit, an operation mode (hereinafter referred to as an idling mode) in which the output power of the power generation unit is controlled so that the output power of the fuel cell unit becomes zero is known (for example, patent document). 2, Non-Patent Document 1).

JP 2010-15783 A JP 2006-12589 A

Osaka Gas Co., Ltd., “SOFC System Technology Development”, [Online], [Search on July 11, 2012], Internet (URL: http://www.osakagas.co.jp/rd/fuelcell/sofc/ technology / system.html)

  However, in the idling mode described above, since the power generation unit is maintained in an idling state, it is necessary to supply fuel (gas, etc.) to the fuel cell unit to the extent that the power generation unit can generate power, which is sufficiently efficient in terms of cost. It cannot be said that it is appropriate.

  Therefore, the present invention has been made to solve the above-described problems, and an object thereof is to provide a control device, a fuel cell unit, and a control method that enable efficient operation control of the fuel cell unit. .

  The control device according to the first feature controls a fuel cell unit including a power generation unit that generates power by a chemical reaction and an auxiliary device that assists the operation of the power generation unit. The control device includes a control unit that instructs the fuel cell unit in an operation mode of the fuel cell unit, and the operation mode of the fuel cell unit follows power consumption of a load connected to the fuel cell unit. In this way, the power generation mode, which is a mode for controlling the power output from the power generation unit, and the power consumed by the auxiliary machine are covered by power supplied from outside the fuel cell unit, and the temperature of the power generation unit is maintained in a predetermined temperature range. And a temperature maintenance mode in which power output from the power generation unit is smaller than power consumption of the auxiliary device. The control unit calculates, for each of the operation modes of the fuel cell unit, the cost of the fuel required in the fuel cell unit to cover the power consumption of the load and the power supplied from other than the fuel cell unit, A low-cost operation mode is instructed based on the calculated cost.

  1st characteristic WHEREIN: The said predetermined temperature range is a temperature range lower than the electric power generation temperature at the time of generating electric power in the said electric power generation part in the said electric power generation mode.

  In the first feature, the control unit instructs, as one of the operation modes of the fuel cell unit, a self-sufficiency mode for controlling the power output from the power generation unit to be consumed by the auxiliary machine, and the control unit Calculates the cost of fuel required by the fuel cell unit and the power supplied from other than the fuel cell unit for each of the temperature maintenance mode and the self-supply mode when the power consumption of the load falls below a predetermined threshold Then, a low-cost operation mode is instructed based on the calculated cost.

  In the first feature, the control unit instructs the operation mode of the fuel cell unit to be the self-sufficiency mode when a power failure occurs.

  In the first feature, the predetermined temperature range is lower than the temperature of the power generation unit in the self-sufficiency mode.

  In the first feature, the fuel cell unit includes a SOFC fuel cell.

  In the first feature, the power generation temperature is 650 ° C. to 1000 ° C., and the predetermined temperature range is 450 ° C. to 600 ° C.

  In the first feature, the amount of fuel supplied to the power generation unit in the temperature maintenance mode is smaller than the amount of fuel supplied to the power generation unit in the self-sustained mode.

  The fuel cell unit according to the second feature includes a power generation unit that generates power by a chemical reaction and an auxiliary device that assists the operation of the power generation unit. The fuel cell unit covers a power generation mode that is a mode in which power generation by the power generation unit is actively performed, and power consumption of the auxiliary machine by power supplied from outside, and maintains the temperature of the power generation unit in a predetermined temperature range. And a control unit that controls its own operation in a plurality of operation modes including a temperature maintenance mode in which the power output from the power generation unit is smaller than the power consumption of the auxiliary device. The control unit calculates, for each of the operation modes of the fuel cell unit, the cost of the fuel required in the fuel cell unit to cover the power consumption of the load and the power supplied from other than the fuel cell unit, Based on the calculated cost, self-operation is controlled by a low-cost operation mode.

  A control method according to a third feature is a method of controlling a fuel cell unit including a power generation unit that generates power by a chemical reaction and an auxiliary device that assists the operation of the power generation unit. The control method includes a step of instructing an operation mode of the fuel cell unit to the fuel cell unit. The operation mode of the fuel cell unit includes a power generation mode in which power output from the power generation unit is controlled so as to follow power consumption of a load connected to the fuel cell unit, and power consumption of the auxiliary device. Covering with power supplied from the outside and performing control to maintain the temperature of the power generation unit in a predetermined temperature range, including a temperature maintenance mode in which the power output from the power generation unit is smaller than the power consumption of the auxiliary device . The control method calculates, for each of the operation modes of the fuel cell unit, the cost of the fuel required in the fuel cell unit to cover the power consumption of the load and the power supplied from other than the fuel cell unit, A low-cost operation mode is instructed based on the calculated cost.

  ADVANTAGE OF THE INVENTION According to this invention, the control apparatus, fuel cell unit, and control method which provide the control apparatus and control method which enable efficient operation control of a fuel cell unit can be provided.

FIG. 1 is a diagram illustrating an energy management system 100 according to the first embodiment. FIG. 2 is a diagram illustrating the customer 10 according to the first embodiment. FIG. 3 is a view showing the fuel cell unit 150 according to the first embodiment. FIG. 4 is a diagram illustrating the EMS 200 according to the first embodiment. FIG. 5 is a flowchart showing the control method according to the first embodiment.

  Hereinafter, a control device and a control method according to an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

  However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones. Therefore, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

[Outline of Embodiment]
The control device according to the embodiment controls a fuel cell unit including a power generation unit that generates power by a chemical reaction and an auxiliary device that assists the operation of the power generation unit. The control device includes a control unit that instructs the fuel cell unit in an operation mode of the fuel cell unit, and the operation mode of the fuel cell unit follows power consumption of a load connected to the fuel cell unit. In this way, the power generation mode, which is a mode for controlling the power output from the power generation unit, and the power consumed by the auxiliary machine are covered by power supplied from outside the fuel cell unit, and the temperature of the power generation unit is maintained in a predetermined temperature range. And a temperature maintenance mode in which the power output from the power generation unit is smaller than the power consumption of the auxiliary device, and the control unit includes the load for each of the operation modes of the fuel cell unit. The fuel required by the fuel cell unit to cover the power consumption and the cost of power supplied from other than the fuel cell unit Out, and it instructs the low-cost operation modes based on the cost that the calculated.

  In the embodiment, a plurality of operation modes including a power generation mode and a temperature maintenance mode are introduced. Thus, even when the fuel cell unit is not completely stopped to ensure load followability, the fuel cell unit can be efficiently controlled.

[First Embodiment]
(Energy management system)
Hereinafter, the energy management system according to the first embodiment will be described. FIG. 1 is a diagram illustrating an energy management system 100 according to the first embodiment.

  As shown in FIG. 1, the energy management system 100 includes a customer 10, a CEMS 20, a substation 30, a smart server 40, and a power plant 50. The customer 10, the CEMS 20, the substation 30 and the smart server 40 are connected by a network 60.

  The consumer 10 includes, for example, a power generation device and a power storage device. The power generation device is a device that outputs electric power using fuel gas, such as a fuel cell. The power storage device is a device that stores electric power, such as a secondary battery.

  The consumer 10 may be a detached house or an apartment house such as a condominium. Alternatively, the customer 10 may be a store such as a convenience store or a supermarket, a commercial facility such as a building, or a factory.

  In the first embodiment, a customer group 10 </ b> A and a customer group 10 </ b> B are configured by a plurality of consumers 10. The consumer group 10A and the consumer group 10B are classified by, for example, a geographical area.

  The CEMS 20 controls interconnection between the plurality of consumers 10 and the power system. The CEMS 20 may be referred to as a CEMS (Cluster / Community Energy Management System) in order to manage a plurality of consumers 10. Specifically, the CEMS 20 disconnects between the plurality of consumers 10 and the power system at the time of a power failure or the like. On the other hand, the CEMS 20 interconnects the plurality of consumers 10 and the power system when power is restored.

  In the first embodiment, a CEMS 20A and a CEMS 20B are provided. For example, the CEMS 20A controls interconnection between the customer 10 included in the customer group 10A and the power system. For example, the CEMS 20B controls interconnection between the customer 10 included in the customer group 10B and the power system.

  The substation 30 supplies electric power to the plurality of consumers 10 via the distribution line 31. Specifically, the substation 30 steps down the voltage received from the power plant 50.

  In the first embodiment, a substation 30A and a substation 30B are provided. For example, the substation 30A supplies power to the consumers 10 included in the consumer group 10A via the distribution line 31A. For example, the substation 30B supplies power to the consumers 10 included in the consumer group 10B via the distribution line 31B.

  The smart server 40 manages a plurality of CEMSs 20 (here, CEMS 20A and CEMS 20B). The smart server 40 also manages a plurality of substations 30 (here, the substation 30A and the substation 30B). In other words, the smart server 40 comprehensively manages the customers 10 included in the customer group 10A and the customer group 10B. For example, the smart server 40 has a function of balancing the power to be supplied to the consumer group 10A and the power to be supplied to the consumer group 10B.

  The power plant 50 generates power using thermal power, sunlight, wind power, hydraulic power, nuclear power, or the like. The power plant 50 supplies power to the plurality of substations 30 (here, the substation 30A and the substation 30B) via the power transmission line 51.

  The network 60 is connected to each device via a signal line. The network 60 is, for example, the Internet, a wide area network, a narrow area network, a mobile phone network, or the like.

(Customer)
Below, the consumer which concerns on 1st Embodiment is demonstrated. FIG. 2 is a diagram illustrating details of the customer 10 according to the first embodiment.

  As shown in FIG. 2, the customer 10 includes a distribution board 110, a load 120, a PV unit 130, a storage battery unit 140, a fuel cell unit 150, a hot water storage unit 160, and an EMS 200.

  In the first embodiment, the customer 10 has an ammeter 180. The ammeter 180 is used for load following control of the fuel cell unit 150. The ammeter 180 is on the power line connecting the storage battery unit 140 and the fuel cell unit 150 and the system, downstream of the connection point between the storage battery unit 140 and the power line (the side away from the system), and the fuel cell unit 150. It is provided upstream (side closer to the grid) than the connection point with the power line. The ammeter 180 is provided upstream (side closer to the system) than the connection point between the load 120 and the power line. However, the present invention can also be implemented when the connection of the fuel cell unit 150 and the storage battery unit 140 is reversed.

  In the first embodiment, it should be noted that each device is connected to the power line in the order of the PV unit 130, the storage battery unit 140, the fuel cell unit 150, and the load 120 as viewed from the order close to the grid.

  Distribution board 110 is connected to distribution line 31 (system). Distribution board 110 is connected to load 120, PV unit 130, storage battery unit 140, and fuel cell unit 150 via a power line.

  The load 120 is a device that consumes power supplied via a power line. For example, the load 120 includes devices such as a refrigerator, a freezer, lighting, and an air conditioner.

  The PV unit 130 includes a PV 131 and a PCS 132. The PV 131 is an example of a power generation device, and is a solar power generation device that generates power in response to reception of sunlight. The PV 131 outputs the generated DC power. The amount of power generated by the PV 131 changes according to the amount of solar radiation applied to the PV 131. The PCS 132 is a device (Power Conditioning System) that converts DC power output from the PV 131 into AC power. The PCS 132 outputs AC power to the distribution board 110 via the power line.

  In the first embodiment, the PV unit 130 may have a pyranometer that measures the amount of solar radiation irradiated on the PV 131.

  The PV unit 130 is controlled by an MPPT (Maximum Power Point Tracking) method. Specifically, the PV unit 130 optimizes the operating point (a point determined by the operating point voltage value and the power value, or a point determined by the operating point voltage value and the current value) of the PV 131.

  The storage battery unit 140 includes a storage battery 141 and a PCS 142. The storage battery 141 is a device that stores electric power. The PCS 142 is a device (Power Conditioning System) that converts AC power supplied from the distribution line 31 (system) into DC power. Further, the PCS 142 converts DC power output from the storage battery 141 into AC power.

  The fuel cell unit 150 includes a fuel cell 151 and a PCS 152. The fuel cell 151 is an example of a power generation device, and is a device that outputs electric power using fuel gas. The PCS 152 is a device (Power Conditioning System) that converts DC power output from the fuel cell 151 into AC power.

  The fuel cell unit 150 operates by load following control. Specifically, the fuel cell unit 150 controls the fuel cell 151 so that the power output from the fuel cell 151 becomes the target power for load following control. In other words, the fuel cell unit 150 controls the power output from the fuel cell 151 so that the current value detected by the ammeter 180 becomes the target received power. The load follow-up control mentioned here is a control in which, when the power consumption of the load 120 exceeds the output power in the rated operation of the fuel cell unit 150, the shortage of the required power of the load 120 is covered by the power supplied from the system. Including.

  The hot water storage unit 160 is an example of a heat storage device that converts electric power into heat, accumulates the converted heat as hot water, and stores heat generated by a cogeneration device such as the fuel cell unit 150 as hot water. Specifically, the hot water storage unit 160 has a hot water storage tank, and warms water supplied from the hot water storage tank by exhaust heat generated by the operation (power generation) of the fuel cell 151. Specifically, the hot water storage unit 160 warms the water supplied from the hot water storage tank and returns the warmed hot water to the hot water storage tank.

  The EMS 200 is an apparatus (Energy Management System) that controls the PV unit 130, the storage battery unit 140, the fuel cell unit 150, and the hot water storage unit 160. Specifically, the EMS 200 is connected to the PV unit 130, the storage battery unit 140, the fuel cell unit 150, and the hot water storage unit 160 via signal lines, and the PV unit 130, the storage battery unit 140, the fuel cell unit 150, and the hot water storage unit. 160 is controlled. The EMS 200 controls the power consumption of the load 120 by controlling the operation mode of the fuel cell unit 150.

  The EMS 200 is connected to various servers via the network 60. Various servers store, for example, information (hereinafter referred to as energy charge information) such as the unit price of power supplied from the grid, the unit price of power received from the grid, and the unit price of fuel gas.

  Or various servers store the information (henceforth energy consumption prediction information) for predicting the power consumption of the load 120, for example. The energy consumption prediction information may be generated based on, for example, the past power consumption actual value of the load 120. Alternatively, the energy consumption prediction information may be a model of power consumption of the load 120.

  Or various servers store the information (henceforth PV power generation amount prediction information) for predicting the power generation amount of PV131, for example. The PV power generation prediction information may be a predicted value of the amount of solar radiation irradiated on the PV 131. Alternatively, the PV power generation prediction information may be weather forecast, season, sunshine time, and the like.

(Fuel cell unit)
Hereinafter, the fuel cell unit according to the first embodiment will be described. FIG. 3 is a view showing the fuel cell unit 150 according to the first embodiment.

  As shown in FIG. 3, the fuel cell unit 150 includes a fuel cell 151, a PCS 152, a blower 153, a desulfurizer 154, an ignition heater 155, and a control board 156.

  As described above, the fuel cell 151 is a device that outputs electric power using fuel. Specifically, the fuel cell 151 includes a reformer 151A and a cell stack 151B.

  The reformer 151A generates reformed gas from the fuel from which the odorant has been removed by the desulfurizer 154 described later. The reformed gas is a gas composed of hydrogen and carbon monoxide.

  The cell stack 151B generates power by a chemical reaction between air (oxygen) supplied from a blower 153, which will be described later, and the reformed gas. Specifically, the cell stack 151B has a structure in which a plurality of cells are stacked. Each cell has a structure in which an electrolyte is sandwiched between a fuel electrode and an air electrode. Reformed gas (hydrogen) is supplied to the fuel electrode, and air (oxygen) is supplied to the air electrode. A chemical reaction of the reformed gas (hydrogen) and air (oxygen) occurs in the electrolyte to generate electric power (DC electric power) and heat.

  As described above, the PCS 152 is a device that converts DC power output from the fuel cell 151 into AC power.

  The blower 153 supplies air to the fuel cell 151 (cell stack 151B). The blower 153 is configured by a fan, for example.

  The desulfurizer 154 removes the odorant contained in the fuel supplied from the outside. The fuel may be city gas or propane gas.

  The ignition heater 155 is a heater that ignites a fuel that has not chemically reacted in the cell stack 151B (hereinafter, unreacted fuel) and maintains the temperature of the cell stack 151B at a high temperature. That is, the ignition heater 155 ignites unreacted fuel leaking from the opening of each cell constituting the cell stack 151B. It should be noted that the ignition heater 155 may ignite the unreacted fuel in a case where the unreacted fuel is not combusted (for example, when the fuel cell unit 150 is activated). Once ignited, thereafter, the unreacted fuel that overflows little by little from the cell stack 151B continues to burn, so that the temperature of the cell stack 151B is maintained at a high temperature.

  The control board 156 is a board on which a circuit for controlling the fuel cell 151, the PCS 152, the blower 153, the desulfurizer 154, the ignition heater 155, and the control board 156 is mounted.

  In the first embodiment, the cell stack 151B is an example of a power generation unit that generates power by a chemical reaction. The reformer 151A, the blower 153, the desulfurizer 154, the ignition heater 155, and the control board 156 are examples of auxiliary machines that assist the operation of the cell stack 151B (power generation unit). A part of the PCS 152 may be handled as an auxiliary machine.

  In the first embodiment, as the operation mode of the fuel cell unit 150, a power generation mode, a self-supply mode, and a temperature maintenance mode are provided.

  The power generation mode is an operation mode (load following control) in which the power output from the fuel cell 151 (cell stack 151B) is controlled so as to follow the power consumption of the load 120 connected to the fuel cell unit 150. Specifically, in the power generation mode, the power output from the fuel cell 151 is controlled so that the received power calculated from the current value detected by the ammeter 180 and the voltage value measured by the PCS 152 becomes the target received power. Is done. Here, since the fuel cell unit 150 is provided downstream of the ammeter 180, it should be noted that the power consumption of the auxiliary equipment is also covered by the power output from the fuel cell 151.

  Here, the temperature of the cell stack 151B in the power generation mode is maintained at a power generation temperature of 650 to 1000 ° C. (for example, about 700 ° C.) by chemical reaction and combustion of unreacted fuel. Such a power generation temperature is a temperature range in which a chemical reaction occurs positively if the reformed gas (hydrogen) and air (oxygen) are obtained.

  Incidentally, the fuel cell unit 150 can be completely stopped. For example, it may be completely stopped when it is not used for a long time. However, when the engine is completely stopped, the auxiliary machines are also stopped and the temperature of the fuel cell 151 (cell stack 151B) becomes low, so it takes a long time to increase the temperature to a level at which power generation is possible. Therefore, it should be noted that the load followability is low. For this reason, in the first embodiment, in order to avoid a complete stop as much as possible, an idling mode and a temperature maintenance mode are provided in the operation mode.

  The self-sufficiency mode is an operation mode in which the power consumed by the auxiliary equipment is covered by the power output from the fuel cell 151 (cell stack 151B). The self-sufficiency mode here is a mode controlled so that the output power from the fuel cell unit 150 becomes zero, and is also referred to as an idling mode. It should be noted that the power consumption of the load 120 is not covered by the power output from the fuel cell 151 in the idling mode (self-sufficiency mode).

  Here, the temperature of the cell stack 151B in the idling mode is maintained at the same power generation temperature (for example, about 700 ° C.) as that in the power generation mode due to the chemical reaction and the combustion of the unreacted fuel. That is, the temperature of the cell stack 151B in the idling mode is a temperature range in which a chemical reaction is positively generated if the reformed gas (hydrogen) and air (oxygen) are obtained, as in the power generation mode. The idling mode is an operation mode applied when a power failure occurs, for example.

  The temperature maintenance mode is an operation mode in which the power consumption of the auxiliary equipment is covered by power supplied from the outside and the cell stack 151B is maintained in a predetermined temperature range. In the temperature maintenance mode, the power consumption of the auxiliary machine may be covered by power supplied from the grid, or may be supplied by power supplied from the PV 131 or the storage battery 141. In the temperature maintenance mode, the power output from the fuel cell 151 (cell stack 151B) is at least smaller than the power consumption of the auxiliary machine, and is slightly less than that for operating the auxiliary machine as in the idling mode. For example, power is not output from the fuel cell 151 (cell stack 151B) in the temperature maintenance mode.

  Here, the temperature of the cell stack 151B in the temperature maintenance mode is mainly maintained by the combustion of unreacted fuel. In addition, the temperature of the cell stack 151B in the temperature maintenance mode is lower than the temperature of the cell stack 151B in the power generation mode. Similarly, the temperature of the cell stack 151B in the temperature maintenance mode is lower than the temperature of the cell stack 151B in the idling mode. However, due to the combustion of unreacted fuel, the temperature of the cell stack 151B in the temperature maintenance mode is maintained at a certain high temperature (predetermined temperature range).

  In the first embodiment, the predetermined temperature range is slightly lower than the power generation temperature, for example, about 450 ° C. to 600 ° C. Even if the reformed gas (hydrogen) and air (oxygen) are obtained, a sufficient chemical reaction is achieved. This is the temperature range where it is difficult to occur. When the temperature of the cell stack 151B is within a predetermined temperature range, the reaction speed of the chemical reaction is insufficient, so that the voltage output from the fuel cell 151 (cell stack 151B) is lower than the rated voltage (200V). In the temperature maintenance mode, no chemical reaction may occur or some chemical reaction may occur. However, since the predetermined temperature range is maintained at a temperature that is clearly higher than room temperature, even when it is necessary to generate power, a chemical reaction is actively generated compared to a state where the power supply is completely stopped. The time until the temperature is reached is short, and the time until the necessary power is output is shortened.

  Further, the amount of fuel supplied to the fuel cell unit 150 in the temperature maintenance mode is smaller than the amount of fuel supplied to the fuel cell unit 150 in the idling mode.

(Configuration of EMS)
Hereinafter, the EMS of the first embodiment will be described. FIG. 4 is a block diagram showing the EMS 200 of the first embodiment.

  As illustrated in FIG. 4, the EMS 200 includes a reception unit 210, a transmission unit 220, and a control unit 230.

  The receiving unit 210 receives various signals from a device connected via a signal line. For example, the receiving unit 210 may receive information indicating the power generation amount of the PV 131 from the PV unit 130. The receiving unit 210 may receive information indicating the storage amount of the storage battery 141 from the storage battery unit 140. The receiving unit 210 may receive information indicating the power generation amount of the fuel cell 151 from the fuel cell unit 150. The receiving unit 210 may receive information indicating the amount of hot water stored in the hot water storage unit 160 from the hot water storage unit 160.

  In the first embodiment, the reception unit 210 may receive energy charge information, energy consumption prediction information, and PV power generation amount prediction information from various servers via the network 60. However, the energy fee information, the energy consumption prediction information, and the PV power generation amount prediction information may be stored in the EMS 200 in advance.

  The transmission unit 220 transmits various signals to a device connected via a signal line. For example, the transmission part 220 transmits the signal for controlling the PV unit 130, the storage battery unit 140, the fuel cell unit 150, and the hot water storage unit 160 to each apparatus. The transmission unit 220 transmits a control signal for controlling the load 120 to the load 120.

  The control unit 230 controls the load 120, the PV unit 130, the storage battery unit 140, the fuel cell unit 150, and the hot water storage unit 160.

  In the first embodiment, the control unit 230 instructs the fuel cell unit 150 about the operation mode of the fuel cell unit 150. In the first embodiment, the operation mode of the fuel cell unit 150 includes a power generation mode (load following control), an idling mode, and a temperature maintenance mode as described above.

  The control unit 230 calculates the fuel and / or power costs required to cover the power consumption of the load 120 for each operation mode of the fuel cell unit 150, and compares the calculated costs. The control unit 230 receives power consumption of the load 120 calculated from the current value detected by the ammeter 180 and the voltage value measured by the PCS 152, and energy rate information stored in various servers, particularly supplied from the grid. The fuel and / or power costs required to cover the power consumption of the load 120 are calculated based on the information about the power purchase unit price and the fuel gas purchase unit price.

  Here, the cost of fuel and / or electric power required to cover the power consumption of the load 120 means the following. In the power generation mode, it means the fuel supplied to the fuel cell 151 (cell stack 151B) in order to cover the power consumption of the load 120 with the output power from the fuel cell unit 150. In the case of the temperature maintenance mode, the fuel supplied to the fuel cell 151 (cell stack 151B) in order to maintain the temperature of the fuel cell 151 (cell stack 151B) in a predetermined temperature range, and the supplement to cover the power consumption of the auxiliary equipment. It means the power supplied to the machine and the power supplied to the load 120 to cover the power consumption of the load 120. In the idling mode, the power supplied to the fuel cell 151 (cell stack 151B) and the power consumption of the load 120 are covered by the power output from the fuel cell 151 (cell stack 151B) to cover the power consumption of the auxiliary equipment. Therefore, the power supplied to the load 120 is meant. The control unit 230 controls the fuel cell unit 150 to operate in an operation mode in which the cost of fuel and / or power required to cover the power consumption of the load 120 is small.

  In addition, when the power consumption of the load falls below a predetermined threshold, the control unit 230 calculates the fuel and / or power cost required for the fuel cell unit for each of the temperature maintenance mode and the self-sufficiency mode, and compares the calculated costs. Thus, the operation mode of the fuel cell unit 150 can be instructed to be the temperature maintenance mode or the idling mode.

  In the temperature maintenance mode, the fuel and / or power costs required by the fuel cell unit 150 are the fuel cell 151 (cell stack 151B) for maintaining the temperature of the fuel cell 151 (cell stack 151B) in a predetermined temperature range. Means the power supplied to the auxiliary equipment and the power supplied to the auxiliary equipment to cover the power consumption of the auxiliary equipment. In the idling mode, the power consumed by the auxiliary equipment is output from the fuel cell 151 (cell stack 151B). It means the fuel supplied to the fuel cell 151 (cell stack 151B) to cover electric power. The control unit 230 can operate the fuel cell unit 150 in the operation mode in which the fuel and / or power cost required by the fuel cell unit is smaller when the power consumption of the load falls below a predetermined threshold.

  For example, at night when the power consumption of the load 120 is almost zero and the unit price of power received from the grid is low, the power consumption of the auxiliary equipment and the load 120 is the output power from the fuel cell 151 (cell stack 151B). In some cases, it is more efficient to cover with power supplied from the grid than to cover it. In such a case, the control unit 230 can perform efficient operation control while ensuring load followability by controlling the fuel cell unit 150 to operate in the temperature maintenance mode. In addition, for example, when a power failure occurs, the control unit 230 controls the fuel cell unit 150 to operate in the idling mode.

(Control method)
Hereinafter, a control method according to the first embodiment will be described. FIG. 5 is a flowchart showing the control method according to the first embodiment.

  As shown in FIG. 5, in step 100, the EMS 200 calculates the cost in each mode of the fuel cell unit 150. As described above, the operation mode of the fuel cell unit 150 includes the power generation mode, the idling mode, and the temperature maintenance mode. The cost here is a cost calculated from the cost of fuel and / or power supplied to the fuel cell unit 150 and the cost of power supplied from the system to cover the power consumption of the load 120. Specifically, in the power generation mode, when the power consumption of the load 120 is covered by the output power from the fuel cell unit 150, the cost is calculated only from the fuel supplied to the fuel cell unit 150. Even in the power generation mode, if the power consumption in the load 120 cannot be covered only by the output power from the fuel cell unit 150, the cost is calculated including the power supplied to the load 120 from the system. In the idling mode, the cost is calculated from the fuel supplied to the fuel cell unit 150 and the power supplied to the load 120 from the system in order to cover the power consumption of the load 120 with the power supplied from the system. In the case of the temperature maintenance mode, since the power consumption of the auxiliary equipment is covered by the power supplied from the system, the cost is calculated from the fuel and power supplied to the fuel cell unit 150 and the power supplied to the load 120 from the system. Is calculated.

  In step 200, the EMS 200 compares the cost of each operation mode calculated in step 100, and instructs the operation mode of the fuel cell unit 150. Specifically, the EMS 200 controls the fuel cell unit 150 to operate in the lowest cost operation mode.

  In step 200, when the EMS 200 determines that the power generation mode is the lowest cost operation mode, the EMS 200 controls the fuel cell unit 150 to operate in the power generation mode. In the power generation mode, the auxiliary devices are controlled so as to follow the power consumption of the load 120 connected to the fuel cell unit 150, and the output from the fuel cell 151 is adjusted.

  In step 200, when the EMS 200 determines that the temperature maintenance mode is the lowest cost operation mode, the EMS 200 controls the fuel cell unit 150 to operate in the temperature maintenance mode. As described above, in the temperature maintenance mode, the power consumption of the auxiliary equipment is covered by the power from the system and the power supplied from other than the fuel cell unit such as the PV unit 130, and the temperature of the cell stack 151B is within the predetermined temperature range. Maintained. In the temperature maintenance mode, the power output from the fuel cell 151 is at least smaller than the power consumption of the auxiliary machine and may be zero. That is, for example, at night when the power consumption of the load 120 is low and the purchase unit price of power supplied from the grid is low, the power consumption of the auxiliary equipment and the load 120 is from the grid rather than using the output power from the cell stack 151B. It may be more efficient to cover with supplied power. In such a case, the EMS 200 can efficiently control the operation of the fuel cell unit 150 by instructing the temperature maintenance mode as the operation mode.

  In step 200, the EMS 200 calculates a cost for each of the temperature maintenance mode and the self-sufficiency mode when the power consumption of the load 120 falls below a predetermined threshold. That is, in the case of the temperature maintenance mode, the cost of the fuel supplied to the fuel cell unit 150 and the power supplied from other than the fuel cell unit 150 to the auxiliary machine is calculated, and in the case of the idling mode, the cost is supplied to the fuel cell unit 150. Calculate the cost of the fuel to be used. Based on these calculated costs, when the EMS 200 determines that the idling mode is a lower cost operation mode than the temperature maintenance mode, the EMS 200 controls the fuel cell unit 150 to operate in the idling mode. As a result, even when the power consumption of the load 120 is very small and the power generation mode can be excluded from the operation mode options, the operation mode is indicated by comparing the costs for the temperature maintenance mode and the idling mode. By doing so, the fuel cell unit 150 can be efficiently controlled. Further, for example, when a power failure occurs, the EMS 200 may control the fuel cell unit 150 to operate in the idling mode. In the idling mode, the operation can be continued even when the system is in a power failure state and cannot receive power from the system. Even if the system is in a power failure state and the auxiliary machines cannot receive power supply from the system, the power generation in the fuel cell 151 (cell stack 151B) is a chemical reaction and does not stop immediately. That is, even if a power failure occurs and power supply from the grid to the auxiliary equipment is lost, the chemical reaction continues for a while to cover the power consumption of the auxiliary equipment. For this reason, even if a power failure is detected, the operation can be continued by immediately changing the power supply source to the auxiliary machine from the system to its own generated power. Thus, as described above, in the idling mode, the power output from the fuel cell 151 is supplied to the auxiliary device, but the power is not basically supplied to the load 120.

  As described above, in the first embodiment, a plurality of operation modes including the temperature maintenance mode are introduced. Accordingly, even when the fuel cell unit 150 is not completely stopped to ensure load followability, the fuel cell unit 150 can be efficiently controlled.

[Other Embodiments]
Although the present invention has been described with reference to the above-described embodiments, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, in the temperature maintenance mode, the power consumption of the auxiliary machinery is covered by the power supply from the system, but it may be covered by the output of the PV unit 130 or the storage battery unit 140.

  In the embodiment, the control device is the EMS 200, but the embodiment is not limited thereto. The EMS 200 may be a PCS 152 or a control board 156.

  The EMS 200 may be a HEMS (Home Energy Management System), a SEMS (Store Energy Management System), a BEMS (Building Energy Management System), or an FEM. There may be.

  In the embodiment, the customer 10 includes a load 120, a PV unit 130, a storage battery unit 140, a fuel cell unit 150, and a hot water storage unit 160. However, the consumer 10 should just have the load 120 and the fuel cell unit 150 at least.

  DESCRIPTION OF SYMBOLS 10 ... Consumer, 20 ... CEMS, 30 ... Substation, 31 ... Distribution line, 40 ... Smart server, 50 ... Power plant, 51 ... Transmission line, 60 ... Network, 100 ... Energy management system, 110 ... Distribution board, DESCRIPTION OF SYMBOLS 120 ... Load, 130 ... PV unit, 131 ... PV, 132 ... PCS, 140 ... Storage battery unit, 141 ... Storage battery, 142 ... PCS, 150 ... Fuel cell unit, 151 ... Fuel cell, 151A ... Reformer, 151B ... Cell Stack, 152 ... PCS, 153 ... Blower, 154 ... Desulfurizer, 155 ... Ignition heater, 156 ... Control board, 160 ... Hot water storage unit, 180 ... Ammeter, 200 ... EMS, 210 ... Receiver, 220 ... Transmitter, 230 ... Control unit

Claims (8)

A control device that controls a fuel cell unit including a power generation unit that generates power by a chemical reaction and an auxiliary device that assists the operation of the power generation unit,
A controller for instructing the fuel cell unit in an operation mode of the fuel cell unit;
The operation mode of the fuel cell unit is maintained at a power generation temperature by combustion of a chemical reaction and unreacted gas, and controls the power output from the power generation unit so as to follow the power consumption of a load connected to the fuel cell unit. A power generation mode that is a mode to perform power supply, and power consumption of the auxiliary device is covered by power supplied from the outside of the fuel cell unit, and the temperature of the power generation unit is less likely to cause the chemical reaction due to combustion of the unreacted gas. The temperature maintenance mode is a mode in which the electric power output from the power generation unit is smaller than the power consumption of the auxiliary device, and the electric power output from the power generation unit is not supplied to the load. And an idling mode in which the temperature of the power generation unit is maintained at the power generation temperature ,
The predetermined temperature range in the temperature maintenance mode is lower than the power generation temperature in the power generation mode and the idling mode,
The control unit calculates, for each of the operation modes of the fuel cell unit, the cost of the fuel required in the fuel cell unit to cover the power consumption of the load and the power supplied from other than the fuel cell unit, A control device that instructs a low-cost operation mode based on the calculated cost. When the power consumption of the load is lower than a predetermined threshold, the control unit is configured to supply the fuel required for the fuel cell unit and the power supplied from other than the fuel cell unit for each of the temperature maintenance mode and the idling mode. calculating a cost control device according to claim 1, characterized in that to direct the low-cost operation modes based on the cost that the calculated. The control device according to claim 1 , wherein the control unit instructs the operation mode of the fuel cell unit to be the idling mode when a power failure occurs.   The control apparatus according to claim 1, wherein the fuel cell unit includes a SOFC fuel cell. The control device according to claim 1 , wherein the power generation temperature is 650 ° C to 1000 ° C, and the predetermined temperature range is 450 ° C to 600 ° C. The amount of fuel supplied to the power generation unit at said temperature maintaining mode, the control device according to claim 1, characterized in that less than the amount of fuel supplied to the power generation unit in the idle mode. A fuel cell unit including a power generation unit that generates power by a chemical reaction and an auxiliary device that assists the operation of the power generation unit,
A power generation mode that is a mode for controlling the power output from the power generation unit so as to follow the power consumption of the load connected to the fuel cell unit, maintained at the power generation temperature by the combustion of the chemical reaction and the unreacted gas , The power generation of the auxiliary machine is covered by the power supplied from the outside, and the temperature of the power generation unit is controlled to be maintained within a predetermined temperature range where the chemical reaction hardly occurs by combustion of the unreacted gas, and the power generation Temperature maintaining mode in which the power output from the power generation unit is smaller than the power consumption of the auxiliary device, and the power output from the power generation unit is not supplied to the load, and the temperature of the power generation unit is maintained at the power generation temperature. A control unit that controls its own operation by a plurality of operation modes including an idling mode .
The predetermined temperature range in the temperature maintenance mode is lower than the power generation temperature in the power generation mode and the idling mode,
The control unit calculates, for each of the operation modes of the fuel cell unit, the cost of the fuel required in the fuel cell unit to cover the power consumption of the load and the power supplied from other than the fuel cell unit, A fuel cell unit that controls its own operation in a low-cost operation mode based on the calculated cost. A control method for controlling a fuel cell unit including a power generation unit that generates power by a chemical reaction and an auxiliary device that assists the operation of the power generation unit,
Instructing the operation mode of the fuel cell unit to the fuel cell unit,
The operation mode of the fuel cell unit is maintained at a power generation temperature by combustion of a chemical reaction and unreacted gas, and controls the power output from the power generation unit so as to follow the power consumption of a load connected to the fuel cell unit. Power generation mode, and power consumption of the auxiliary machine is covered by externally supplied power, and the temperature of the power generation unit is maintained in a predetermined temperature range in which the chemical reaction hardly occurs due to combustion of the unreacted gas. , A temperature maintenance mode in which the power output from the power generation unit is smaller than the power consumption of the auxiliary machine, and the power output from the power generation unit is not supplied to the load, and the temperature of the power generation unit is the power generation temperature Including an idling mode maintained at
The predetermined temperature range in the temperature maintenance mode is lower than the power generation temperature in the power generation mode and the idling mode,
For each of the operation modes of the fuel cell unit, the cost of the fuel required by the fuel cell unit to cover the power consumption of the load and the power supplied from other than the fuel cell unit is calculated, and the calculated cost is A control method characterized by indicating a low-cost operation mode based on the control method.

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