Power supply system, control device, and control method

Abstract

A technology is provided that makes it possible to appropriately supply power to a load device using a power storage device or a fuel cell during a power outage in a power grid. [Solution] A power supply system 30 according to one embodiment includes a fuel cell module 110, a power storage device 200 electrically connected to the fuel cell module 110, a power conversion device 300 electrically connected to the fuel cell module 110 and the power storage device 200 and capable of outputting power supplied from at least one of the fuel cell module 110 and the power storage device 200 to an external load device 20, and a control device 500 that controls the fuel cell module 110 and the power conversion device 300.When a power outage occurs in the AC power system 10 that supplies power to the load device 20 while the fuel cell module 110 and the power conversion device 300 are out of operation, the control device 500 starts up the fuel cell module 110 using power from the power storage device 200 and also starts up the power conversion device 300.

Description

[Technical field]

[0001] The present disclosure relates to a power supply system and the like. [Background technology]

[0002] For example, there are known technologies that, during a power outage in a power grid that supplies power to a load device, supply power from a power storage device to the load device, or start up a fuel cell independently using power from the power storage device and supply power from the fuel cell to the load device (see Patent Documents 1 to 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-68547 A [Patent Document 2] JP 2016-46982 A [Patent Document 3] JP 2013-243794 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, there is room for improvement in the method of supplying power to the load device during a power outage in the power grid.

[0005] In view of the above-mentioned problems, an object of the present invention is to provide a technique that can appropriately supply power to a load device using a power storage device or a fuel cell during a power outage in a power grid. [Means for solving the problem]

[0006] In order to achieve the above object, in one embodiment of the present disclosure, A fuel cell; an electricity storage device electrically connected to the fuel cell; One end The fuel cell and the power storage device are electrically connected The other end is electrically connected to an external load device.The power supplied from at least one of the fuel cell and the power storage device is The above a power conversion device capable of outputting to a load device; a control device for controlling the fuel cell and the power conversion device, when a power grid that supplies power to the load device experiences a power outage while the fuel cell and the power conversion device are out of operation, the control device starts up the fuel cell and the power conversion device using power from the power storage device. A power supply system is provided.

[0007] In another embodiment of the present disclosure, a fuel cell; and a power storage device electrically connected to the fuel cell; One end The fuel cell and the power storage device are electrically connected The other end is electrically connected to an external load device. The power supplied from at least one of the fuel cell and the power storage device is The above A power supply system including a power conversion device capable of outputting to a load device, When a power grid that supplies power to the load device experiences a power outage while the fuel cell and the power conversion device are out of operation, the fuel cell is started up using power from the power storage device, and the power conversion device is also started up. A controller is provided.

[0008] In still another embodiment of the present disclosure, a fuel cell; and a power storage device electrically connected to the fuel cell; One end The fuel cell and the power storage device are electrically connected The other end is electrically connected to an external load device. The power supplied from at least one of the fuel cell and the power storage device is The above A control method executed by a control device for a power supply system including a power conversion device capable of outputting power to a load device, When a power grid that supplies power to the load device experiences a power outage while the fuel cell and the power conversion device are out of operation, the fuel cell is started up using power from the power storage device, and the power conversion device is also started up. A control method is provided. Effect of the Invention

[0009] According to the above-described embodiment, when a power outage occurs in the power grid, power can be appropriately supplied to the load device using the power storage device or the fuel cell. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating a configuration of a first example of a power system. [Diagram 2] FIG. 11 is a diagram illustrating a configuration of a second example of a power system. [Diagram 3] FIG. 13 is a diagram illustrating a configuration of a third example of a power system. [Figure 4] FIG. 1 is a diagram showing a configuration of an example of a fuel cell system. [Diagram 5] 4 is a flowchart illustrating an example of a control process related to a normal startup of a fuel cell system. [Figure 6] 5 is a time chart illustrating a comparative example of a control method for independent startup of a fuel cell system. [Figure 7] 4 is a flowchart illustrating a first example of a control process related to the independent startup of the fuel cell system 100. [Figure 8] 4 is a time chart illustrating a first example of a control method for independent startup of a fuel cell system. [Figure 9] 6 is a flowchart illustrating a second example of a control process related to the independent startup of the fuel cell system 100. [Figure 10] 6 is a time chart illustrating a second example of a control method for independent startup of a fuel cell system. [Figure 11] 13 is a flowchart showing a third example of the operation of the power supply system during a power outage in the AC power grid. [Figure 12] 6 is a time chart illustrating a third example of a control method for independent startup of a fuel cell system. [Figure 13] 13 is a flowchart showing a fourth example of the operation of the power supply system during a power outage in the AC power grid. [Figure 14] 13 is a flowchart showing a fourth example of the operation of the power supply system during a power outage in the AC power grid. [Figure 15] 13 is a flowchart showing a fourth example of the operation of the power supply system during a power outage in the AC power grid. [Figure 16] 6 is a time chart illustrating a fourth example of a control method for independent startup of a fuel cell system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment will be described with reference to the drawings.

[0012] [Power system configuration] The configuration of a power system 1 according to this embodiment will be described with reference to FIGS. 1 to 3.

[0013] Fig. 1 is a diagram showing a configuration of a first example of the power system 1. Fig. 2 is a diagram showing a configuration of a second example of the power system 1. Fig. 3 is a diagram showing a configuration of a third example of the power system 1.

[0014] 2, the fuel cell systems 100 all have the same configuration, so the fuel cell module 110 and the auxiliary equipment 120 are depicted in only one of the fuel cell systems 100. In addition, in Fig. 3, the configuration of each of the power supply systems 30 is the same as that in Fig. 1 or 2, so the illustration of each component is omitted.

[0015] As shown in FIGS. 1 to 3, a power system 1 includes an AC power system 10, a load device 20, and a power supply system 30. The load device 20 is a load device that is connected to the power supply system 30.

[0016] The power system 1 connects the power supply system 30 to the AC power system 10 through the power distribution system 40, and can supply power output from the power supply system 30 to a demand side connected to the AC power system 10. Furthermore, the power system 1 can distribute power from the AC power system 10 to the load device 20 and the power supply system 30 through the power distribution system 40. Furthermore, the power system 1 can supply power from the power supply system 30 to the load device 20 through the power distribution system 40.

[0017] The AC power system 10 transmits electric power output from the power supply system 30, other power generation facilities, etc., to a demand side by AC. The AC power system 10 transmits three-phase AC by, for example, a three-phase three-wire system.

[0018] The load device 20 is electrically connected to the AC power system 10 and the power supply system 30 through the power distribution system 40, and operates on power supplied from at least one of the AC power system 10 and the power supply system 30. The load device 20 may be one or more as shown in Figs. 1 to 3. The load device 20 is, for example, various types of equipment installed in the same factory as the power supply system 30. The various types of equipment in the factory include, for example, outlets, lighting, production equipment, etc. The power supply system 30 is connected to the AC power system 10 through the power distribution system 40 and can supply power to the AC power system 10. The power supply system 30 can also receive power from the AC power system 10 through the power distribution system 40. The power supply system 30 is also electrically connected to the load device 20 through the power distribution system 40 and can supply power to the load device 20.

[0019] 1 and 2, one power supply system 30 is provided for one power distribution system 40. Furthermore, as shown in FIG 3, a plurality of power supply systems 30 may be connected in parallel to one power distribution system 40.

[0020] As shown in FIGS. 1 and 2, the power supply system 30 includes a fuel cell system 100, a power storage device 200, a power conversion device 300, a transformer 400, and a control device 500.

[0021] The fuel cell system 100 supplies electric power to an AC power system 10 via a power conversion device 300 and a transformer 400. The fuel cell system 100 is electrically connected to the power storage device 200 and the power conversion device 300 via a DC link unit 250.

[0022] For example, as shown in Fig. 1, one fuel cell system 100 is provided. Alternatively, as shown in Fig. 2, a plurality of fuel cell systems 100 may be provided. In this case, the plurality of fuel cell systems 100 are connected to the DC link unit 250 in parallel.

[0023] The fuel cell system 100 includes a fuel cell module 110 that receives a fuel supply and generates power, and an auxiliary device 120 for operating the fuel cell module 110. The auxiliary device 120 is operated by power supplied from a DC link unit 250.

[0024] The power storage device 200 can discharge power to the outside of the power supply system 30 through the power conversion device 300 and the transformer 400, and can charge (store) power distributed from the AC power system 10 and power of the fuel cell system 100 through the DC link unit 250. The power storage device 200 is, for example, a capacitor such as a lithium ion capacitor (LIC). The power storage device 200 may also be, for example, a storage battery (secondary battery) such as a lithium ion battery with a liquid electrolyte or an all-solid-state battery with a solid electrolyte. The power storage device 200 is electrically connected to the fuel cell system 100 and the power conversion device 300 through the DC link unit 250.

[0025] 1 and 2, the number of the power storage device 200 may be one or more. In the latter case, the multiple power storage devices 200 may be connected in series or in parallel to the DC link unit 250. Alternatively, a series connection of two or more power storage devices 200 may be connected in parallel to the DC link unit 250.

[0026] The power conversion device 300 converts the DC of the DC link unit 250 into AC of a predetermined voltage and frequency, and outputs it to the transformer 400. For example, the power conversion device 300 is a power conditioner (PCS: Power Conditioning System) including an inverter circuit that converts the DC into three-phase AC of a predetermined voltage and frequency.

[0027] An inrush current prevention circuit (also referred to as a "pre-charge circuit") may be provided on the power supply line (DC line) on the DC side of the DC link unit 250 or the power conversion device 300. The inrush current prevention circuit has a first electric path for supplying the DC of the DC link unit 250 directly to the inverter circuit of the power conversion device 300, and a second electric path provided in parallel with the first electric path and including a resistor for preventing inrush current. The control device 500 can electrically connect the DC link unit 250 and the inverter circuit of the power conversion device 300 by connecting either one of relays that are provided on both the first electric path and the second electric path and can be switched between electrical connection and non-connection. For example, immediately after starting the power conversion device 300, the smoothing capacitor arranged on the DC side of the power conversion device 300 is not charged, and if the DC link unit 250 and the inverter circuit are connected through the first electric path, a very large current (inrush current) may flow, causing damage to the circuit. In contrast, immediately after starting the power conversion device 300 from a stopped state, the control device 500 connects the relay of the second electric path and disconnects the relay of the first electric path. As a result, a relatively small current flows from the DC link unit 250 to the power conversion device 300 due to the action of the resistor for preventing inrush current of the second electric path, and the capacitor is charged (pre-charged) relatively slowly. Then, at a timing when it can be determined that the capacitor is sufficiently charged, the control device 500 changes the relay of the first electric path to a connected state and the relay of the second electric path to a disconnected state.

[0028] The transformer 400 transforms (specifically, boosts) the AC output from the power conversion device 300 and outputs the AC power to the AC power system 10 and the load device 20 via the power distribution system 40.

[0029] For example, as shown in Fig. 1, when the power supply system 30 includes only one fuel cell system 100, one combination of the power conversion device 300 and the transformer 400 is provided. Also, when the power supply system 30 includes only one fuel cell system 100, a plurality of combinations of the power conversion device 300 and the transformer 400 may be provided in parallel. Also, when the power supply system 30 includes a plurality of fuel cell systems 100, one combination of the power conversion device 300 and the transformer 400 may be provided, or a plurality of combinations of the power conversion device 300 and the transformer 400 may be provided in parallel as shown in Fig. 2. As shown in Fig. 2, when a plurality of combinations of the power conversion device 300 and the transformer 400 are provided, the power conversion device 300 and the transformer 400 are connected in parallel to the power distribution system 40 and the DC link unit 250. Furthermore, as shown in FIG. 2, when multiple combinations of power conversion devices 300 and transformers 400 are provided, the number of combinations of power conversion devices 300 and transformers 400 and the number of fuel cell systems 100 may be the same or different.

[0030] The control device 500 controls the operation of the power supply system 30. For example, as shown in Fig. 1 and Fig. 2, the control device 500 operates on power supplied from the power distribution system 40. In this case, if a power outage occurs in the AC power system 10 while the fuel cell system 100 and the power conversion device 300 are out of operation, the control device 500 operates on power from an auxiliary power source (not shown). The control device 500 may also operate on power supplied from the DC link unit 250.

[0031] For example, the control device 500 controls the fuel cell system 100 and the power conversion device 300 in accordance with the power required by the demand side (demand side request) connected to the AC power system 10, and causes the power conversion device 300 to output power corresponding to the demand side request. Specifically, the control device 500 may control the load of the power conversion device 300 so as to output AC power corresponding to the demand side request from the DC of the DC link unit 250, and may also control the fuel cell system 100 to output power corresponding to the demand side request. In this way, the control device 500 can cause the fuel cell system 100 to output power corresponding to the demand side request to the AC power system 10 side through the power conversion device 300.

[0032] Furthermore, for example, the control device 500 performs processing (start-up processing) for starting up the fuel cell system 100 in a stopped state, and processing (stop processing) for stopping the fuel cell system 100 in an operating state. Starting up the fuel cell system 100 means starting up the auxiliary equipment 120 of the fuel cell system 100 in a stopped state of the fuel cell system 100, and starting up the fuel cell module 110 while operating the auxiliary equipment 120. Stopping the fuel cell system 100 means stopping the operation of the fuel cell module 110 by stopping the auxiliary equipment 120.

[0033] The functions of the control device 500 can be realized arbitrarily by any hardware or any combination of hardware and software. For example, the control device 500 is a PLC (Programmable Logic Controller). The control device 500 may also be configured with a computer including a CPU (Central Processing Unit), a main storage device (memory device), an auxiliary storage device, an interface device, and the like as a central component. This allows the control device 500 to realize various functions by the CPU executing a program pre-installed in the storage device (e.g., the auxiliary storage device).

[0034] [Fuel cell system configuration] The configuration of a fuel cell system 100 according to this embodiment will be described with reference to FIG.

[0035] FIG. 4 is a diagram showing a configuration of an example of the fuel cell system 100. As shown in FIG.

[0036] As shown in FIG. 4, the fuel cell system 100 includes a fuel cell module 110, a fuel supply section 130, an air intake section 140, a discharge section 150, and a cooling section 160.

[0037] The fuel cell module 110 includes a fuel cell 112 , a cooling section 114 , and a converter device 116 .

[0038] The fuel cell 112 generates electricity by chemically reacting hydrogen as fuel supplied from the fuel supply unit 130 with oxygen in the air taken in from the air intake unit 140. The fuel cell 112 is, for example, a polymer electrolyte fuel cell (PEFC). For example, the fuel cell 112 as a polymer electrolyte fuel cell has a stack structure in which a large number of unit cells are stacked.

[0039] A single cell in the fuel cell 112 has a membrane electrode assembly (MEA) including a polymer electrolyte membrane and a pair of electrodes provided on both sides of the polymer electrolyte membrane. The polymer electrolyte membrane selectively transports hydrogen ions. Each electrode is made of a porous material. Each of the pair of electrodes has a catalyst layer mainly composed of carbon powder carrying a platinum-based metal catalyst (electrode catalyst), for example, and a gas diffusion layer having both air permeability and electronic conductivity. Furthermore, the single cell has a pair of separators that sandwich the membrane electrode assembly (MEA) from both sides.

[0040] The fuel cell 112 may be, for example, a phosphoric acid fuel cell (PAFC) or a solid oxide fuel cell (SOFC). The fuel cell 112 may be, for example, a molten carbonate fuel cell (MCFC).

[0041] Water remaining after the chemical reaction between hydrogen and oxygen in the air and exhaust gas are discharged from the fuel cell 112 to the exhaust section 150 .

[0042] The cooling unit 114 cools the fuel cell 112. Specifically, a coolant flows inside the cooling unit 114. The cooling unit 114 can cool the fuel cell 112 by exchanging heat between the fuel cell 112 and the coolant.

[0043] The converter device 116 boosts the voltage output from the fuel cell 112 and outputs it to the outside of the fuel cell module 110. The output terminal of the converter device 116 is connected to the DC link section 250.

[0044] The fuel supply unit 130 supplies hydrogen as fuel to the fuel cell 112. The fuel supply unit 130 includes a hydrogen supply source 131, an on-off valve 132, a pump 133, and a gas-liquid separator 134.

[0045] The hydrogen supply source 131 stores high-pressure hydrogen and supplies high-pressure hydrogen gas through a supply path L1 to the fuel cell 112 of the fuel cell module 110. The hydrogen supply source 131 is, for example, a hydrogen cartridge.

[0046] The on-off valve 132 is a valve that opens and closes the supply path L1. When the on-off valve 132 is in a closed state, this indicates a state in which the supply path L1 is blocked and the supply of hydrogen from the hydrogen supply source 131 to the fuel cell 112 is stopped, and when the on-off valve 132 is in an open state, this indicates a state in which hydrogen is pressure-fed from the hydrogen supply source 131 to the fuel cell 112. The on-off valve 132 operates using power supplied from the power distribution system 40 under the control of the control device 500. The on-off valve 132 is one of the accessories 120.

[0047] The pump 133 is provided in a circulation path L2 that returns excess hydrogen gas discharged from the fuel cell 112 to the supply path L1. The circulation path L2 merges with the supply path L1 downstream of the on-off valve 132. The pump 133 pumps the hydrogen gas in the circulation path L2 to the supply path L1. The pump 133 operates using power supplied from the power distribution system 40 under the control of the control device 500. The pump 133 is one of the accessories 120.

[0048] The gas-liquid separator 134 is provided in the circulation path L2. The gas-liquid separator 134 separates a liquid component (water) from the multiphase fluid containing hydrogen gas discharged from the fuel cell 112, and causes the hydrogen gas to flow downstream of the circulation path L2.

[0049] The air intake section 140 takes in air from the outside, and supplies the air through an air intake path L3 to the fuel cell 112. The air intake section 140 includes an air cleaner 142, a compressor 144, and an on-off valve 146.

[0050] The air cleaner 142 removes dust, impurities, and the like contained in the air taken in from one end of the air supply path L3.

[0051] The compressor 144 is provided downstream of the air cleaner 142 in the air supply path L3. The compressor 144 compresses the air that has passed through the air cleaner 142, and sends the compressed air to the fuel cell 112 through the downstream air supply path L3. The compressor 144 operates using power supplied from the power distribution system 40 under the control of the control device 500. The compressor 144 is one of the accessories 120.

[0052] The on-off valve 146 is a valve that opens and closes the air supply path L3. The on-off valve 146 is provided in the air supply path L3 between the compressor 144 and the fuel cell 112. When the on-off valve 146 is in a closed state, the air supply path L3 is blocked and the supply of air to the fuel cell 112 is stopped, and when the on-off valve 146 is in an open state, the on-off valve 146 is in an open state, where air can be supplied to the fuel cell 112 through the air supply path L3. The on-off valve 146 operates using power supplied from the power distribution system 40 under the control of the control device 500. The on-off valve 146 is one of the auxiliary machines 120.

[0053] The discharge unit 150 discharges water produced by a chemical reaction between hydrogen and oxygen contained in the air in the fuel cell 112 and the remaining air (exhaust gas) to the outside via a discharge path L4. The discharge unit 150 includes an on-off valve 152, a mixer 154, and a gas-liquid separator 156.

[0054] The on-off valve 152 is a valve that opens and closes the discharge path L4. The on-off valve 152 is provided at the most upstream portion of the discharge path L4. When the on-off valve 152 is in a closed state, this indicates a state in which the discharge of water and exhaust gas from the fuel cell 112 is stopped, and when the on-off valve 152 is in an open state, this indicates a state in which the water and exhaust gas can be discharged from the fuel cell 112 to the outside through the discharge path L4. The on-off valve 152 operates using power supplied from the power distribution system 40 under the control of the control device 500. The on-off valve 152 is one of the accessories 120.

[0055] The mixer 154 causes the water separated by the gas-liquid separator 134 to merge with the discharge path L4.

[0056] The water separated by the gas-liquid separator 134 may be discharged to the outside through a discharge path other than the discharge path L4.

[0057] The gas-liquid separator 156 is provided in the discharge path L4 downstream of the mixer 154. The gas-liquid separator 156 separates the gas-liquid two-phase fluid in the discharge path L4 into liquid (water) and gas (exhaust gas), and discharges the liquid and gas to the outside.

[0058] The cooling section 160 supplies a coolant for cooling the fuel cell 112 to the cooling section 114. The cooling section 160 includes a cooler 161, a fan 162, a pump 163, a heat exchanger 164, a pump 165, and an ion exchanger 166.

[0059] The cooler 161 cools the coolant in the cooling circuit CC1. Thus, the heat exchanger 164 exchanges heat between the coolant in the cooling circuit CC1 and the coolant in the cooling circuit CC2, and can cool the coolant in the cooling circuit CC2. The cooler 161 is, for example, a cooling tower. The cooler 161 may also be a radiator. The radiator is, for example, a fin-tube type or a fin-and-tube type radiator.

[0060] The fan 162 generates an airflow that passes through the cooler 161. This can promote cooling of the coolant in the cooling circuit CC1 that passes through the cooler 161. The fan 162 operates using power supplied from the power distribution system 40 under the control of the control device 500. The fan 162 is one of the accessories 120.

[0061] The pump 163 is provided in the cooling circuit CC1 and circulates the coolant in the cooling circuit CC1. The pump 163 operates using power supplied from the power distribution system 40 under the control of the control device 500. The pump 163 is one of the accessories 120.

[0062] The heat exchanger 164 exchanges heat between the coolant in the cooling circuit CC1 including the cooler 161 and the coolant in the cooling circuit CC2 including the cooling unit 114, thereby cooling the coolant in the cooling circuit CC2. This allows the cooling circuit CC2 to supply the coolant cooled by the heat exchanger 164 to the cooling unit 114, thereby cooling the fuel cell 112.

[0063] The pump 165 is provided in the cooling circuit CC2 and circulates the coolant in the cooling circuit CC2. The pump 165 operates using power supplied from the power distribution system 40 under the control of the control device 500. The pump 165 is one of the accessories 120.

[0064] The ion exchanger 166 is provided in the cooling circuit CC2 and serves to remove ionic impurities from the cooling liquid in the cooling circuit CC2, thereby ensuring the insulation of the cooling liquid.

[0065] Hereinafter, the auxiliary device 120 included in the cooling section 160 may be referred to as the "cooling auxiliary device 120."

[0066] [Control method for normal startup of fuel cell system] A control method for normal startup of the fuel cell system 100 (first to third examples) will be described with reference to FIG. 5 in addition to FIGS. 1 to 4.

[0067] Normal startup of the fuel cell system 100 refers to startup of the fuel cell system 100 in a state in which power supply from the AC power system 10 through the power distribution system 40 to the fuel cell system 100 is possible.

[0068] <Summary> When conditions (normal startup conditions) for performing normal startup of the fuel cell system 100 are met while the fuel cell system 100 is in a stopped state (hereinafter simply referred to as the "stopped state"), the control device 500 starts up the fuel cell system 100. Specifically, the control device 500 operates the auxiliary machinery 120 using power supply from the AC power system 10 to start up the fuel cell module 110.

[0069] The normal startup conditions for the fuel cell system 100 are, for example, that the fuel cell system 100 is stopped, the AC power system 10 is in a state where it can normally supply power, and a startup command for the fuel cell system 100 is input.

[0070] The start-up command for the fuel cell system 100 is input to the control device 500 in response to, for example, a user's operation input to an operation unit connected to the control device 500. The start-up command for the fuel cell system 100 may also be input to the control device 500 by communication from an external device in response to a user's operation input to an external device such as a higher-level device of the control device 500 or a user terminal carried by the user. The higher-level device of the control device 500 is, for example, a management terminal device or an edge server installed in a facility where the power supply system 30 is installed. The higher-level device of the control device 500 may also be, for example, an on-premise server or a cloud server installed in a management center located in a different location from the facility where the power supply system 30 is installed. The start-up command for the fuel cell system 100 may also be automatically generated according to a predetermined rule. For example, the start-up command is generated inside the control device 500 at a preset time and input to the control device 500 in a pseudo manner. The start-up command may also be generated in an external device at a preset time and input to the control device 500 from the external device by communication.

[0071] The control device 500 starts up all of the auxiliaries 120 of the fuel cell system 100 using power supplied from the AC power system 10 via the power distribution system 40, thereby causing the fuel cell system 100 to perform a normal startup.

[0072] <Control processing> FIG. 5 is a flow chart showing an example of a control process related to the normal startup of the fuel cell system 100. As shown in FIG.

[0073] This flowchart is executed repeatedly at predetermined processing intervals during operation of the control device 500. The same applies to the processes in Figs. 7, 9, 11, and 13 described below.

[0074] 5, in step S10, the control device 500 determines whether or not the normal startup conditions of the fuel cell system 100 are met. If the normal startup conditions of the fuel cell system 100 are met, the control device 500 proceeds to step S20, and if the normal startup conditions of the fuel cell system 100 are not met, the control device 500 ends the processing of this flowchart.

[0075] In step S20, the control device 500 operates the auxiliary devices 120 using power from the power storage device 200 to start up the fuel cell module 110. If the power supply system 30 includes multiple fuel cell systems 100, the control device 500 starts up all of the fuel cell modules 110 included in each of the fuel cell systems 100.

[0076] When the process of step S20, i.e., the start-up of the fuel cell module 110, is completed, the control device 500 proceeds to step S30. When starting up multiple fuel cell modules 110, the control device 500 proceeds to step S30 when the start-up of all of the fuel cell modules 110 is completed.

[0077] In step S30, the control device 500 controls the fuel cell system 100 to start power generation of the fuel cell module 110. If the power supply system 30 includes multiple fuel cell systems 100, the control device 500 starts power generation of all the fuel cell modules 110 included in each of all the fuel cell systems 100.

[0078] When the process of step S30 is completed, the control device 500 proceeds to step S40.

[0079] In step S40, the control device 500 starts up the power electronics device 300. When the power supply system 30 includes a plurality of power electronics devices 300, the control device 500 starts up all of the power electronics devices 300.

[0080] When the process of step S40, i.e., the start-up of the power electronics device 300, is completed, the control device 500 proceeds to step S50. When the power supply system 30 includes a plurality of power electronics devices 300, when the start-up of all the power electronics devices 300 is completed, the control device 500 proceeds to step S50.

[0081] In step S50, the control device 500 starts outputting power from the power conversion device 300 to the outside (i.e., the transformer 400 side). When the power supply system 30 includes a plurality of power conversion devices 300, the control device 500 starts outputting power from each of all the power conversion devices 300 to the outside (i.e., the transformer 400 side).

[0082] This allows the control device 500 to supply power from the power conversion device 300 to the power distribution system 40 via the transformer 400.

[0083] When the process of step S50 is completed, the control device 500 ends the process of this flowchart.

[0084] [Comparative example of control method for independent startup of fuel cell system] A comparative example of a control method for the independent startup of the fuel cell system 100 will be described with reference to FIG. 6 in addition to FIGS.

[0085] Independent startup of the fuel cell system 100 means a state in which it is not possible to supply power from the AC power system 10 to the fuel cell system 100 via the power distribution system 40, i.e., startup of the fuel cell system 100 without external power supply during a power outage in the AC power system 10.

[0086] 6 is a time chart illustrating a comparative example of a control method for the independent startup of the fuel cell system 100. Specifically, the time chart shows a comparative example of the change over time in the amount of stored electricity in the electricity storage device 200 during independent startup of the fuel cell system 100 and the flow of operation of the electricity supply system.

[0087] In this comparative example, a control method for the independent startup of the fuel cell system 100 is realized by a control process similar to that in the case of normal startup of the fuel cell system 100 (FIG. 5).

[0088] 5, it is determined whether or not the conditions for performing independent startup of the fuel cell system 100 (independent startup conditions) are met. If the independent startup conditions for the fuel cell system 100 are met, the processing from step S20 onwards is executed, and if the independent startup conditions for the fuel cell system 100 are not met, the processing of this flowchart is terminated.

[0089] The independent startup condition for the fuel cell system 100 is, for example, that the fuel cell system 100 is stopped and that the AC power system 10 is experiencing a power outage. Alternatively, the independent startup condition for the fuel cell system 100 may be that the fuel cell system 100 is stopped and that the AC power system 10 is experiencing a power outage and that a startup command for the fuel cell system 100 is input. For example, the control device 500 can determine whether or not there is a power outage in the AC power system 10 based on the measurement results of a measuring device installed in the power distribution system 40, a signal input by communication from a management device that manages the AC power system 10, or the like.

[0090] Then, when the processing of step S50 is completed, the load devices that have been out of operation due to a power outage in the AC power system 10 start operating using power supplied from the fuel cell system 100 to the power distribution system 40, and the processing of the flowchart ends.

[0091] As shown in Fig. 6, in response to the establishment of the independent startup conditions of the fuel cell system 100, startup of the fuel cell module 110 is initiated at time t01 (step S20 in Fig. 5). Thereafter, at time t02, startup of the fuel cell module 110 is completed, power generation of the fuel cell module is initiated (step S30 in Fig. 5), and startup of the power conversion device 300 is initiated (step S40 in Fig. 5). Thereafter, at time t03, startup of the power conversion device 300 is completed, and power supply from the fuel cell system 100 to the power distribution system 40 is initiated (step S50 in Fig. 5), and accordingly, operation (operation) of the load device 20 is initiated.

[0092] In the comparative example, during the period from time t01 to time t02 when the fuel cell module 110 is started, power is supplied from the power storage device 200 to the auxiliary device 120, and the amount of stored power in the power storage device 200 decreases over time. Then, at time t02, when the fuel cell module 110 starts generating power, the decrease in the amount of stored power in the power storage device 200 stops, and from time t02 onwards, the amount of stored power in the power storage device 200 is maintained constant.

[0093] During the period from when the fuel cell module 110 starts generating power until the start-up of the power conversion device 300 is completed, that is, from time t02 to time t03, the power storage device 200 may be charged with power from the fuel cell module 110, and the amount of power stored in the power storage device 200 may increase. Furthermore, during the period after time t03, the fuel cell system 100 may be controlled so that the power generated by the fuel cell module 110 is greater than the demand on the load side, including the power consumption of the load device 20. In this case, the power storage device 200 is charged with the surplus power of the fuel cell module 110 (see the dashed line after time t03 in the figure).

[0094] Here, in the comparative example, the power conversion device 300 is started up after the start-up of the fuel cell module 110 is completed. Therefore, after the fuel cell module 110 starts generating electricity, a waiting time occurs before the load device 20 starts operating (in this example, the period from time t02 to time t03), and the timing at which the load device 20 starts operating is delayed.

[0095] Furthermore, at the time when the start-up of the fuel cell module 110 is completed, the remaining amount of stored electricity in the power storage device 200 (hereinafter, "remaining stored electricity amount") is sufficiently greater than the allowable lower limit, and surplus electricity is generated. In other words, the power storage device 200 not only supplies the power required to start up the fuel cell module 110, but also has surplus electricity sufficient to operate the load device 20 before the start-up of the fuel cell module 110 is completed. Therefore, in the control method of this comparative example, the resources of the power storage device 200 are not fully used when the load device 20 starts operating.

[0096] Thus, the control method of the comparative example has room for improvement in terms of accelerating the timing at which the load device 20 starts operating and the timing at which the fuel cell module 110 starts supplying power to the load device 20.

[0097] [First example of a control method for autonomous startup of a fuel cell system] A first example of a control method for independent startup of the fuel cell system 100 will be described with reference to FIGS. 7 and 8 in addition to FIGS. 1 to 4.

[0098] <Control processing> FIG. 7 is a flow chart showing a first example of a control process related to the independent startup of the fuel cell system 100. As shown in FIG.

[0099] 7, in step S102, the control device 500 determines whether or not the automatic start-up conditions of the fuel cell system 100 are met. If the automatic start-up conditions are met, the control device 500 executes the processes of steps S104 and S106, and the processes of steps S108, S110, and S112 in parallel. On the other hand, if the automatic start-up conditions are not met, the control device 500 ends the process of this flowchart.

[0100] Steps S104 and S106 are the same as steps S20 and S30 in FIG. 5, and therefore a description thereof will be omitted.

[0101] Steps S108 and S110 are the same as steps S40 and S50 in FIG. 5, and therefore description thereof will be omitted.

[0102] When the process of step S110 is completed, the control device 500 proceeds to step S112.

[0103] In step S112, the control device 500 starts the operation (operation) of the load device 20. When there are a plurality of load devices 20, the control device 500 starts the operation of all the load devices 20.

[0104] In addition, the control device 500 may start operation of the load device 20 by outputting a command directly to the load device 20, or may start operation of the load device 20 by outputting a command to another control device that can directly control the load device 20.

[0105] When the control device 500 completes the processes of both steps S106 and S112, it ends the process of this flowchart.

[0106] <Power supply system operation> 8 is a time chart illustrating a first example of a control method for the independent startup of the fuel cell system 100. Specifically, the time chart shows a first example of the change over time in the amount of stored electricity in the electricity storage device 200 and the flow of operations of the electricity supply system during independent startup of the fuel cell system 100.

[0107] As shown in Fig. 8, in response to the establishment of the independent start-up condition of the fuel cell system 100, at time t11, the power storage device 200 supplies power to the auxiliary device 120 to start up the fuel cell module 110 (step S104 in Fig. 7), and the power conversion device 300 starts to start up (step S108 in Fig. 7). Then, at time t12, when the power conversion device 300 completes its start-up before the fuel cell module 110 does, the fuel cell system 100 starts supplying power to the power distribution system 40 through the power conversion device 300 (step S110 in Fig. 7), and accordingly, the load device 20 starts to operate (step S112 in Fig. 7). Then, at time t13, when the start-up of the fuel cell module 110 is completed, the fuel cell module 110 starts to generate power (step S106 in Fig. 7).

[0108] Thus, in this example, unlike the comparative example described above, the control device 500 starts the startup of the power conversion device 300 before the startup of the fuel cell module 110 is completed. This enables the control device 500 to advance the timing of the startup completion of the power conversion device 300. Therefore, the control device 500 can operate the load device 20 with the power generated by the fuel cell module 110 at an earlier stage.

[0109] Furthermore, in this example, unlike the comparative example described above, the control device 500 starts up the fuel cell module 110 and the power conversion device 300 in parallel. That is, in this example, the period required to start up the fuel cell module 110 overlaps with the period required to start up the power conversion device 300. This allows the control device 500 to shorten the time required to complete the start-up of both the fuel cell module 110 and the power conversion device 300, starting from the point in time when the independent start-up condition is met. Therefore, the control device 500 can operate the load device 20 with the power generated by the fuel cell module 110 at an earlier stage.

[0110] Furthermore, assuming that the periods required for the start-up of the fuel cell module 110 and the power conversion device 300 overlap, the timing of the start-up of the fuel cell module 110 and the power conversion device 300 may be the same, as described above, or any one of them may start before the other.

[0111] Furthermore, in this example, the control device 500 completes the startup of the power conversion device 300 before completing the startup of the fuel cell module 110. As a result, the control device 500 can start supplying power from the fuel cell module 110 to the power distribution system 40 via the power conversion device 300 at time t13, immediately after the startup of the fuel cell module 110 is completed. Therefore, the control device 500 can operate the load device 20 with the power generated by the fuel cell module 110 at an earlier stage.

[0112] Furthermore, on the assumption that the timing of completion of startup of the power conversion device 300 is before the timing of completion of startup of the fuel cell module 110, the timing of start-up of the power conversion device 300 may be either before or after the timing of start-up of the fuel cell module 110.

[0113] As shown in FIG. 8, during the period from the start of the activation of the fuel cell module 110 and the power conversion device 300 to the completion of the activation of the power conversion device 300, i.e., the period from time t11 to time t12, power is supplied from the power storage device 200 only to the auxiliary device 120. Therefore, during this period, the amount of stored power in the power storage device 200 decreases in chronological order. At time t12, the activation of the power conversion device 300 is completed, and the power conversion device 300 starts to output power to the power distribution system 40, and the operation of the load device 20 starts. Therefore, during the period until the activation of the fuel cell module 110 is completed, i.e., the period from time t12 to time t13, power is supplied from the power storage device 200 to the auxiliary device 120 as well as the load device 20. Therefore, during this period, the amount of stored power in the power storage device 200 decreases faster than in the previous period (the period from time t11 to time t12). Then, at time t13, when the fuel cell module 110 starts generating power, the decrease in the amount of stored electricity in the electricity storage device 200 stops, and after time t13, the amount of stored electricity (remaining stored electricity) in the electricity storage device 200 is maintained constant at a level slightly higher than the allowable lower limit.

[0114] In addition, in the period after time t13, the fuel cell system 100 may be controlled so that the generated power of the fuel cell module 110 is greater than the power consumed by the load device 20. In this case, the power storage device 200 is charged with the surplus power of the fuel cell module 110 (see the dashed line after time t13 in the figure).

[0115] Thus, in this example, the control device 500 outputs power from the power conversion device 300 to the power distribution system 40 and supplies power to the load device 20 during the period from when the power conversion device 300 completes startup (time t12) to when the fuel cell module 110 completes startup. This allows the control device 500 to start supplying power to the load device 20 before the fuel cell module 110 completes startup. Therefore, the control device 500 can quickly restart the load device 20 when a power outage occurs in the AC power system 10.

[0116] [Second example of control method for autonomous startup of fuel cell system] A second example of a control method for independent startup of the fuel cell system 100 will be described with reference to FIGS. 9 and 10 in addition to FIGS. 1 to 4.

[0117] In the following, in this example, the description will be centered on the parts that are different from the first example of the control method described above, and the description of the parts that are the same as or correspond to the first example of the control method described above may be omitted.

[0118] <Control processing> FIG. 9 is a flow chart showing a second example of a control process related to the independent startup of the fuel cell system 100. In FIG.

[0119] 9, in step S202, the control device 500 determines whether or not the independent startup conditions for the fuel cell system 100 are met. If the independent startup conditions for the fuel cell system 100 are met, the control device 500 proceeds to step S204, and if the independent startup conditions for the fuel cell system 100 are not met, the control device 500 ends the processing of this flowchart.

[0120] In step S204, the control device 500 calculates the operable time TW of the load device 20.

[0121] The operable time TW of the load device 20 means the time during which the load device 20 can be operated (operated) only by the power supply from the power storage device 200, on the premise that the fuel cell module 110 is started up by the power of the power storage device 200. In other words, the operable time TW of the load device 20 is the time during which the load device 20 can be operated by the amount of power that can be supplied to the outside (i.e., dischargeable) out of the remaining amount of stored power obtained by subtracting the amount of power required from the start of startup to the completion of startup of the fuel cell module 110 from the current amount of stored power (remaining amount of stored power) of the power storage device 200 (i.e., the time before the start of startup of the fuel cell module 110). For example, a lower limit value of the amount of stored power (remaining amount of stored power) is predefined for the power storage device 200 from the viewpoint of suppressing deterioration, etc., and the power that the power storage device 200 can supply to the outside is a value obtained by subtracting the lower limit value from the amount of stored power (remaining amount of stored power). When the power supply system 30 includes multiple fuel cell systems 100, in this example, the operable time TW of the load device 20 is defined on the premise that all fuel cell modules 110 corresponding to all fuel cell systems 100 are started up with the power of the power storage device 200. Also, when there are multiple load devices 20 that should be operated with power from the power distribution system 40, in this example, the operable time TW of the load device 20 means the time during which all the load devices 20 can be operated (operated).

[0122] For example, the control device 500 calculates the operable time TW of the load device 20 using the following formula (1).

[0123]

number

[0124] The amount of electric power S1 is the amount of electric power that the power storage device 200 can supply to the outside (i.e., can discharge) before the start of startup of the fuel cell module 110. The amount of electric power S1 corresponds to the difference between the amount of stored electric power (remaining amount of stored electric power) of the power storage device 200 before the start of startup of the fuel cell module 110 and the allowable lower limit value of the amount of stored electric power in the power storage device 200 (or the allowable lower limit value plus a margin).

[0125] The amount of power S2 is the amount of power required to start up the fuel cell module 110, specifically, the amount of power required to operate the auxiliary equipment 120 from the start of start-up of the fuel cell module 110 to the completion of start-up. When the power supply system 30 includes multiple fuel cell systems 100, the amount of power S2 corresponds to the total amount of power required to start up all of the fuel cell modules 110 corresponding to all of the fuel cell systems 100. For example, the amount of power S2 is defined in advance as a constant. Furthermore, the amount of power S2 may be defined in advance as a variable that changes depending on various conditions, such as the atmospheric temperature of the fuel cell system 100 and the temperature at a predetermined location of the fuel cell system 100.

[0126] The conversion efficiency η is a conversion efficiency from DC to AC (orthogonal conversion efficiency) of the power conversion device 300. The conversion efficiency η is defined in advance as a constant. Alternatively, the conversion efficiency η may be defined in advance as a variable that changes depending on various conditions such as the ambient temperature of the power conversion device 300 and the temperature at a predetermined location in the power conversion device 300.

[0127] The power Pc is the power consumption of the load device 20. When there are multiple load devices 20 to be operated, the power Pc is the total of the power consumption of all the load devices 20. The power Pc is predefined as a constant based on the configuration of the load device 20. Furthermore, the power Pc may be predefined as a variable that changes depending on various conditions such as the ambient temperature of the load device 20 and the temperature at a predetermined location in the load device 20.

[0128] The control device 500 can calculate the amount of power S1 (estimated value) based on the measured value of the voltage of the power storage device 200. For example, when the power storage device 200 is a capacitor such as a LIC, the control device 500 can calculate the amount of power S1 based on the following formula (2).

[0129]

number

[0130] The capacitance C is the capacitance of the power storage device 200.

[0131] Voltage V1 is the voltage of the power storage device 200 before start-up of the fuel cell module 110. Voltage V1 is measured, for example, by a voltage sensor built into the power storage device 200, and a signal representing the measurement result is input to the control device 500.

[0132] Voltage V2 is a lower limit value of the voltage of power storage device 200 that is permissible due to discharge. Voltage V2 may be a voltage obtained by adding a margin to the lower limit value. Voltage V2 is defined in advance as a constant. Voltage V2 may be defined in advance as a variable that changes depending on various conditions such as the ambient temperature of power storage device 200 and the temperature at a predetermined location of power storage device 200.

[0133] When the process of step S204 is completed, the control device 500 executes in parallel the processes of steps S206 and S208, and the processes of steps S210, S212, S214, and S216.

[0134] Steps S206 and S208 are the same as steps S20 and S30 in FIG. 5, and therefore a description thereof will be omitted.

[0135] Steps S210 and S212 are the same as steps S40 and S50 in FIG. 5, and therefore a description thereof will be omitted.

[0136] When the process of step S212 is completed, the control device 500 proceeds to step S214.

[0137] In step S214, the control device 500 determines whether or not a waiting time TP has elapsed since the power conversion device 300 started supplying power to the outside.

[0138] The waiting time TP corresponds to the time obtained by subtracting the operable time TW from the remaining time Tr from the start of power supply to the outside of the power conversion device 300 until the completion of startup of the fuel cell module 110. If the value obtained by subtracting the operable time TW from the remaining time Tr is equal to or less than zero (0), the waiting time TP is set to zero (0).

[0139] If the waiting time TP has elapsed, the control device 500 proceeds to step S216, and if the waiting time TP has not elapsed, the control device 500 repeats the process of step S214 until the waiting time TP has elapsed.

[0140] This enables the control device 500 to delay the timing of starting operation of the load device 20 by the waiting time TP from the start of the power supply from the power conversion device 300 to the outside.

[0141] The process of step S214 may be transferred to a step before the process of step S210. In this case, a predicted value can be used as the remaining time Tr when calculating the waiting time TP. This is because the time required for starting up the fuel cell module 110 and the time required for starting up the power conversion device 300 can be estimated in advance. This allows the control device 500 to delay the timing of starting up the power conversion device 300 by the waiting time TP from the timing of starting up the fuel cell module 110.

[0142] Step S216 is the same as the process in step S112 in FIG. 7, and therefore a description thereof will be omitted.

[0143] When the control device 500 completes the processes of both steps S208 and S216, it ends the process of this flowchart.

[0144] <Power supply system operation> 10 is a time chart illustrating a second example of a control method for the independent startup of the fuel cell system 100. Specifically, the time chart shows a second example of the change over time in the amount of stored electricity in the electricity storage device 200 during independent startup of the fuel cell system 100 and the flow of operations of the power supply system.

[0145] As shown in FIG. 10, in response to the establishment of the independent start-up condition of the fuel cell system 100, at time t21, start-up of the fuel cell module 110 is started (step S206 in FIG. 9), and start-up of the power conversion device 300 is also started (step S210 in FIG. 9). Then, at time t22, when start-up of the power conversion device 300 is completed before start-up of the fuel cell module 110, power supply from the fuel cell system 100 to the power distribution system 40 is started (step S212). Then, at time t23, which corresponds to the time when the waiting time TP has elapsed from time t22 as the starting point, operation (operation) of the load device 20 is started (step S216 in FIG. 9). Then, at time t24, when start-up of the fuel cell module 110 is completed, power generation of the fuel cell module 110 is started (step S208 in FIG. 9).

[0146] During the period from the start of the fuel cell module 110 and the power conversion device 300 to the completion of the start of the power conversion device 300, that is, the period from time t21 to time t22, power is supplied from the power storage device 200 only to the auxiliary device 120. Therefore, during this period, the amount of stored power in the power storage device 200 decreases relatively slowly in time series. At time t22, the start of the power conversion device 300 is completed, and the power conversion device 300 starts to output power to the power distribution system 40, but during the period until the waiting time TP has elapsed, that is, the period from time t22 to time t23, the load device 20 does not start operating. Therefore, during this period, power continues to be supplied from the power storage device 200 only to the auxiliary device 120, and the amount of stored power in the power storage device 200 decreases in time series while maintaining the same rate of change as in the previous period (the period from time t21 to time t22). When the load device 20 starts operating at time t23, during the period until the start-up of the fuel cell module 110 is completed, that is, during the period from time t23 to time t24, power is supplied from the power storage device 200 to the load device 20 in addition to the auxiliary device 120. Therefore, during this period, the stored amount of the power storage device 200 decreases faster than in the previous period (the period from time t22 to time t23). The period from time t23 to time t24 corresponds to the operable time TW of the load device 20. Then, when the fuel cell module 110 starts generating power at time t24, the decrease in the stored amount of the power storage device 200 stops, and after time t24, the stored amount of the power storage device 200 (remaining stored amount) is maintained constant at a level slightly higher than the allowable lower limit.

[0147] In addition, in the period after time t24, the fuel cell system 100 may be controlled so that the generated power of the fuel cell module 110 is greater than the power consumed by the load device 20. In this case, the power storage device 200 is charged with the surplus power of the fuel cell module 110 (see the dashed line after time t24 in the figure).

[0148] Thus, in this example, when the start-up of the power conversion device 300 is completed, if the operable time TW of the load device 20 is shorter than the remaining time Tr until the start-up of the fuel cell module 110 is completed (i.e., power generation starts), the control device 500 delays the start of operation of the load device 20 by the waiting time TP equivalent to the difference. This allows the control device 500 to stably operate the load device 20 using power from the power storage device 200 until the start-up of the fuel cell module 110 is completed, even if the total power consumption of the load device 20 is relatively large.

[0149] If the operable time TW of the load device 20 is shorter than the predicted value of the remaining time Tr until the start-up of the fuel cell module 110 (i.e., the start of power generation) at the time when the start-up of the power conversion device 300 is completed, the control device 500 may delay the start-up timing of the power conversion device 300 from the start-up timing of the fuel cell module 110 by a waiting time TP equivalent to the difference. In this case as well, the same actions and effects are achieved.

[0150] [Third example of control method for autonomous startup of fuel cell system] A third example of a control method for independent startup of the fuel cell system 100 will be described with reference to FIGS. 11 and 12 in addition to FIGS.

[0151] In this example, it is assumed that the power supply system 30 includes a plurality of fuel cell systems 100 (see FIG. 2).

[0152] Hereinafter, in this example, the explanation will be centered on the parts that are different from the first and second examples of the control method described above, and explanations of the parts that are the same as or correspond to the first and second examples of the control method described above may be omitted.

[0153] <Control processing> FIG. 11 is a flow chart showing a third example of a control process related to the independent startup of the fuel cell system 100. In FIG.

[0154] 11, in step S302, the control device 500 determines whether or not the independent startup conditions for the fuel cell system 100 are met. If the independent startup conditions for the fuel cell system 100 are met, the control device 500 proceeds to step S304, and if the independent startup conditions for the fuel cell system 100 are not met, the control device 500 ends the processing of this flowchart.

[0155] In step S304, the control device 500 calculates the operable time TW of the load device 20.

[0156] In this example, the operable time TW of the load device 20 means the time during which the load device 20 can be operated (run) using only power supply from the power storage device 200, under the premise that only a fuel cell module 110 (hereinafter, a "specific fuel cell module 110") included in a specific one of the multiple fuel cell systems 100 (hereinafter, a "specific fuel cell system 100") is started using power from the power storage device 200.

[0157] For example, the control device 500 uses formula (1) to calculate the operable time TW of the load device 20, similar to the second example of the control method described above. However, in this example, the amount of electric power S2 means the amount of electric power required to start up the specific fuel cell module 110, specifically, the amount of electric power required to operate the auxiliary device 120 of the specific fuel cell system 100 from the start of start-up of the specific fuel cell module 110 to the completion of start-up.

[0158] When the process of step S304 is completed, the control device 500 executes in parallel the processes of steps S306, S308, S310, and S312, and the processes of steps S314, S316, S318, and S320.

[0159] In step S306, the control device 500 operates the auxiliary devices 120 of the specific fuel cell system 100 to start up the specific fuel cell module 110.

[0160] When the process of step S306 is completed, the control device 500 proceeds to step S308.

[0161] In step S308, the control device 500 controls the specific fuel cell system 100 to cause the specific fuel cell module 110 to start power generation.

[0162] When the process of step S308 is completed, the process proceeds to step S310.

[0163] In step S310, the control device 500 controls the auxiliary devices 120 of the remaining fuel cell systems 100, excluding a specific fuel cell system 100, among the multiple fuel cell systems 100 included in the power supply system 30, and starts up all of the remaining fuel cell modules 110.

[0164] When the process of step S310 is completed, the control device 500 proceeds to step S312.

[0165] In step S312, the control device 500 controls the remaining fuel cell systems 100 to cause all remaining fuel cell modules 110 to start power generation.

[0166] On the other hand, steps S314 and S316 are the same as the processes in steps S40 and S50 in FIG. 5, and therefore a description thereof will be omitted.

[0167] When the process of step S316 is completed, the control device 500 proceeds to step S318.

[0168] In step S318, the control device 500 determines whether or not a waiting time TP has elapsed since the power conversion device 300 started supplying power to the outside.

[0169] When a specific fuel cell module 110 after startup is complete can only output power for starting up all remaining fuel cell modules 110, the waiting time TP corresponds to the time obtained by subtracting the operable time TW from the remaining time Tr1 from the start of power supply to the outside of the power conversion device 300 to the completion of startup of all fuel cell modules 110. On the other hand, when a specific fuel cell module 110 after startup is complete can output power to operate the load device 20 in addition to the power for starting up all remaining fuel cell modules 110, the waiting time TP corresponds to the time obtained by subtracting the operable time TW from the remaining time Tr2 from the start of power supply to the outside of the power conversion device 300 to the completion of startup of the specific fuel cell module 110. When the value obtained by subtracting the operable time TW from the remaining time Tr1 or the remaining time Tr2 is zero (0) or less, the waiting time TP is set to zero (0).

[0170] If the waiting time TP has elapsed, the control device 500 proceeds to step S320, and if the waiting time TP has not elapsed, the control device 500 repeats the process of step S318 until the waiting time TP has elapsed.

[0171] The process of step S318 may be transferred to a process before step S314. In this case, predicted values ​​may be used as the remaining times Tr1 and Tr2 when calculating the waiting time TP.

[0172] Step S320 is the same as the process in step S112 in FIG. 7, and therefore a description thereof will be omitted.

[0173] When the control device 500 completes the processes of both steps S312 and S320, it ends the process of this flowchart.

[0174] <Power supply system operation> 12 is a time chart illustrating a third example of a control method for the independent startup of the fuel cell system 100. Specifically, the time chart shows a third example of the change over time in the amount of stored electricity in the electricity storage device 200 during independent startup of the fuel cell system 100 and the flow of operations of the electricity supply system.

[0175] As shown in FIG. 12, in response to the establishment of the independent start-up condition of the fuel cell system 100, at time t31, the start-up of the specific fuel cell module 110 is started (step S306 in FIG. 11), and the start-up of the power conversion device 300 is started (step S314 in FIG. 11). Then, at time t32, when the start-up of the power conversion device 300 is completed before the start-up of the specific fuel cell module 110, the fuel cell system 100 starts supplying power to the power distribution system 40 (step S316 in FIG. 11). Then, at time t23, which corresponds to the time when the waiting time TP has elapsed from the start point of time t32, the operation (operation) of the load device 20 is started (step S320 in FIG. 11). Then, at time t34, when the start-up of the specific fuel cell module 110 is completed, the specific fuel cell module 110 starts generating electricity (step S308 in FIG. 11), and the start-up of all the remaining fuel cell modules 110 is started (step S310 in FIG. 11). Thereafter, at time t35, when start-up of all remaining fuel cell modules 110 is completed, power generation by all remaining fuel cell modules 110 is started (step S312 in FIG. 11).

[0176] During the period from the start of activation of the specific fuel cell module 110 and the power conversion device 300 to the completion of activation of the power conversion device 300, that is, the period from time t31 to time t32, power is supplied from the power storage device 200 only to the auxiliary device 120 of the specific fuel cell system 100. Therefore, during this period, the amount of stored power in the power storage device 200 decreases relatively slowly in time series. At time t32, the activation of the power conversion device 300 is completed, and the power conversion device 300 starts to output power to the power distribution system 40, but during the period until the waiting time TP has elapsed, that is, the period from time t32 to time t33, the load device 20 does not start operating. Therefore, during this period, power continues to be supplied from the power storage device 200 only to the auxiliary device 120 of the specific fuel cell system 100, and the amount of stored power in the power storage device 200 decreases in time series while maintaining the same rate of change as in the previous period (the period from time t31 to time t32). When the load device 20 starts operating at time t33, during the period until the start-up of the specific fuel cell module 110 is completed, that is, during the period from time t33 to time t34, the power storage device 200 supplies power to the load device 20 in addition to the auxiliary device 120 of the specific fuel cell system 100. Therefore, during this period, the amount of stored power in the power storage device 200 decreases faster than in the previous period (the period from time t32 to time t33). When the start-up of all the remaining fuel cell modules 110 starts at time t34, during the period until the start-up of all the remaining fuel cell modules 110 is completed, that is, during the period from time t34 to time t35, the power storage device 200 supplies power only to the load device 20. Therefore, during this period, the amount of stored power in the power storage device 200 decreases more slowly than in the previous period (the period from time t33 to time t34). The period from time t33 to time t35 corresponds to the operable time TW of the load device 20. Then, at time t35, when all remaining fuel cell modules 110 start generating electricity, the decrease in the amount of stored electricity in the electricity storage device 200 stops, and after time t35, the amount of stored electricity (remaining stored electricity) in the electricity storage device 200 is maintained constant at a level slightly higher than the allowable lower limit.

[0177] In the period after time t35, the fuel cell system 100 may be controlled so that the generated power of the fuel cell module 110 is greater than the power consumed by the load device 20. In this case, the power storage device 200 is charged with the surplus power of the fuel cell module 110 (see the dashed line after time t35 in the figure).

[0178] Thus, in this example, the control device 500 starts up only a specific fuel cell module 110 using the power of the power storage device 200, and starts up all of the remaining fuel cell modules 110 with the power generated by the specific fuel cell module 110. This allows the control device 500 to shorten the waiting time TP when the total power consumption of the load devices 20 is relatively large. Therefore, the control device 500 can more quickly restart the load devices 20 when a power outage occurs in the AC power system 10.

[0179] As in the second example of the control method described above, when the operable time TW of the load device 20 is shorter than the predicted value of the remaining time Tr1 or Tr2 until the start of startup of the fuel cell module 110 (i.e., the start of power generation) at the time when the start of startup of the power conversion device 300 is completed, the control device 500 may delay the timing of starting the power conversion device 300 from the timing of starting the fuel cell module 110 by a waiting time TP equivalent to the difference. In this case as well, the same actions and effects can be achieved.

[0180] [Fourth example of a control method for autonomous startup of a fuel cell system] A fourth example of a control method for independent startup of the fuel cell system 100 will be described with reference to FIGS. 13 to 15 in addition to FIGS. 1 to 4.

[0181] In this example, it is assumed that there are a plurality of load devices 20 that operate using power from a power distribution system 40 .

[0182] In the following, in this example, the differences from the first to third examples of the control method described above will be mainly described, and descriptions of the same or corresponding parts as the first to third examples of the control method described above may be omitted.

[0183] <Control processing> Figures 13 to 15 are flowcharts that outline a fourth example of the control process related to the independent startup of the fuel cell system 100. Specifically, Figure 13 is a main flowchart of the control process according to this example, and Figures 14 and 15 are sub-flowcharts that respectively show the details of the processes in steps S404 and S414 in Figure 13.

[0184] 13, in step S402, the control device 500 determines whether or not the independent startup conditions for the fuel cell system 100 are met. If the independent startup conditions for the fuel cell system 100 are met, the control device 500 proceeds to step S404, and if the independent startup conditions for the fuel cell system 100 are not met, the control device 500 ends the processing of this flowchart.

[0185] In step S404, the control device 500 calculates the operable time TWx (TW1, ..., TWn) of the load device 20 ranked xth (x=1, ..., n; n is an integer greater than or equal to 2) in the target operating priority order (hereinafter, "operating priority order") for each operating priority order predefined for some or all of the multiple load devices 20.

[0186] The operation priority order indicates the order of priority for operation (restart) with the power of the power storage device 200 before the start-up of the fuel cell module 110 is completed in the event of a power outage in the AC power system 10. The operation priority order is predefined, for example, from the viewpoint of BCP (Business Continuity Planning). For example, the load device 20 with a relatively high operation priority order includes a minimum of electrical loads with relatively low power consumption that should be restored quickly for business continuity, such as an outlet or lighting. The operation priority order may be variable according to the amount of stored power (remaining amount of stored power) of the power storage device 200 when the independent start-up condition is satisfied. For example, the operation priority order is set so that the smaller the amount of stored power of the power storage device 200 when the independent start-up condition is satisfied, the higher the operation priority order of the load device with low power consumption (for example, an outlet or lighting). The operation priority order may be set so that the larger the amount of stored power of the power storage device 200 when the independent start-up condition is satisfied, the higher the operation priority order of the load device with high power consumption (for example, machinery and equipment in a factory).

[0187] Of the multiple load devices 20 receiving power supply from the power distribution system 40, the load devices 20 for which an operation priority order is defined (hereinafter, "priority load devices") may be some or all of them, as described above. When only some of the multiple load devices 20 are priority load devices, the remaining load devices 20 start operating, for example, after the start-up of the fuel cell module 110 is completed. Furthermore, the remaining load devices 20 do not need to be operated when a power outage occurs in the AC power system 10.

[0188] Each of the first to n-th operating priorities may be assigned to only one priority load device, or may be assigned to multiple priority load devices.

[0189] Like the above-mentioned operable time TW, the operable time TWx means the time during which the load device 20 can be operated (run) only by the power supply from the power storage device 200, on the premise that the fuel cell module 110 is started up with the power of the power storage device 200. When the same operational priority is assigned to multiple prioritized load devices, the operable time TWx of the prioritized load device with the xth operational priority means the time during which all of the multiple prioritized load devices with the same operational priority order x can be operated (run) only by the power supply from the power storage device 200, on the premise that the startup of the fuel cell module 110 is completed with the power of the power storage device 200.

[0190] For example, the control device 500 calculates the operable time TWx of the prioritized load device through the process of the sub-flowchart in FIG.

[0191] As shown in FIG. 14, in step S4041, the control device 500 calculates the amount of surplus power SPx.

[0192] The surplus power SPx is the amount of power that the power storage device 200 can supply to the prioritized load device that is ranked xth in the operation priority order, on the premise that the power storage device 200 supplies the power required from the start of startup to the completion of startup of the fuel cell module 110. When the power supply system 30 includes multiple fuel cell systems 100, the surplus power SPx is the amount of power that the power storage device 200 can supply to the prioritized load device that is ranked xth in the operation priority order, on the premise that the power storage device 200 supplies the power required from the start of startup to the completion of startup of all of the fuel cell modules 110.

[0193] For example, the surplus energy SP1 corresponding to the prioritized load device with the first operating priority order is the amount of energy obtained by subtracting the amount of energy required to start up the fuel cell module 110 from the current amount of energy stored (remaining energy storage amount) of the energy storage device 200 (i.e., before the start-up of the fuel cell module 110 begins). Also, the surplus energy SPx corresponding to the prioritized load devices with the second or lower operating priority order is a value obtained by subtracting the amount of energy consumed by the prioritized load device with the operating priority order (x-1) in the operable time TW(x-1) from the surplus energy SP(x-1) corresponding to the prioritized load device with the operating priority order (x-1).

[0194] When the process of step S4041 is completed, the control device 500 proceeds to step S4042.

[0195] In step S4042, control device 500 determines whether the condition of the following formula (2) is satisfied.

[0196]

number

[0197] The power amount Pc_x is the power consumption of a prioritized load device with an operational priority of x. When there are multiple prioritized load devices with an operational priority of x, the power amount Pc_x is the sum of the power consumption of each of the multiple prioritized load devices with an operational priority of x.

[0198] The maximum operable time TWMx is a maximum value of the operable time TWx that is predefined for a prioritized load device with an xth-th order of operation priority. The maximum operable time TWMx is predefined to a value equal to or less than the remaining time Tr (estimated value) from the start of power supply to the outside of the power conversion device 300 to the completion of startup of the fuel cell module 110 (TWMx≦Tr). Moreover, the maximum operable time TWMx corresponding to a prioritized load device with an operation priority level 2 or lower is predefined to a value equal to or less than the maximum operable time TWM(x-1) for the (x-1)th order of operation priority (TWMx≦TWM(x-1)).

[0199] The left side of formula (3) is the amount of power that can be supplied to the prioritized load device with the xth operational priority order by the surplus power amount SPx of the power storage device 200. The right side of formula (3) is the amount of power consumed by the prioritized load device with the xth operational priority order in the maximum operable time TWMx.

[0200] If the condition of formula (2) is satisfied, control device 500 proceeds to step S4043, and if the condition of formula (2) is not satisfied, control device 500 proceeds to step S4045.

[0201] In step S4043, the control device 500 sets the operable time TWx of the load device with the xth highest operating priority to the maximum operable time TWMx.

[0202] When the process of step S4043 is completed, control device 500 proceeds to step S4044.

[0203] In step S4044, the control device 500 judges whether or not there is a priority load device with a lower operating priority. If there is a priority load device with a lower operating priority, the control device 500 repeats the process from step S4041 onwards for the immediately lower priority load device, and if there is no lower priority load device, ends the process of this flowchart.

[0204] On the other hand, in step S4045, the control device 500 sets the operable time TWx of the prioritized load device that is ranked xth in the operational priority order by using the following equation (4).

[0205]

number

[0206] When the process of step S4045 is completed, control device 500 proceeds to step S4046.

[0207] In step S4046, the control device 500 determines whether or not there is a priority load device with a lower operating priority. If there is a priority load device with a lower operating priority, the control device 500 proceeds to step S4047, and if there is no priority load device with a lower operating priority, the control device 500 ends the processing of this flowchart.

[0208] In step S4047, the control device 500 sets all of the operable times TW(x+1), . . . of the priority load devices having lower operational priorities to zero (0).

[0209] When the process of step S4047 is completed, the control device 500 ends the process of this flowchart.

[0210] Returning to FIG. 13, when the process of step S404 is completed, the control device 500 executes in parallel the processes of steps S406 and S408, and the processes of steps S410, S412 and S414.

[0211] Steps S406 and S408 are the same as steps S20 and S30 in FIG. 5, and therefore a description thereof will be omitted.

[0212] Steps S410 and S412 are the same as steps S40 and S50 in FIG. 5, and therefore a description thereof will be omitted.

[0213] When the process of step S412 is completed, the control device 500 proceeds to step S414.

[0214] In step S414, the control device 500 executes a process related to the operation of the prioritized load device based on the operation priority order.

[0215] For example, the control device 500 performs the processes of the sub-flowchart in FIG. 15 in parallel for each operation priority order defined in advance as a process related to the operation of the prioritized load device based on the operation priority order.

[0216] 15, the control device 500 determines whether the available operation time TWx corresponding to the target operation priority level, which was set in step S404, is greater than 0. If the available operation time TWx corresponding to the target operation priority level is greater than 0, the control device 500 proceeds to step S4142, and if it is less than 0 (i.e., if it is 0), the control device 500 ends the processing of this flowchart.

[0217] In step S4142, the control device 500 sets the waiting time TPx of the prioritized load device corresponding to the target operation priority order by using the following formula (5).

[0218]

number

[0219] When the process of step S4142 is completed, control device 500 proceeds to step S4143.

[0220] In step S4143, the control device 500 determines whether or not the waiting time TPx has elapsed from the start of power supply to the outside of the power conversion device 300. If the waiting time TPx has elapsed, the control device 500 proceeds to step S4144, and if the waiting time TPx has not elapsed, the control device 500 repeats the process of step S4143 until the waiting time TPx has elapsed.

[0221] This makes it possible to delay the timing of starting operation of the targeted prioritized load device from the start of power supply from the power conversion device 300 to the outside by the waiting time TPx.

[0222] In step S4144, the control device 500 starts operation of the prioritized load device having the target operation priority order.

[0223] When the process of step S4144 is completed, the control device 500 ends the current flow chart corresponding to the target operating priority level.

[0224] Returning to FIG. 13, when the processes of both steps S408 and S414 are completed, the control device 500 proceeds to step S416.

[0225] In step S416, the control device 500 starts the operation of all the load devices.

[0226] The load devices to be started in step S416 are, among the multiple load devices 20 operating on power from the power distribution system 40, load devices 20 that are not specified as priority load devices, and priority load devices that were not started in the processing of step S414.

[0227] When the process of step S416 is completed, the control device 500 ends the process of this flowchart.

[0228] <Power supply system operation> 16 is a time chart illustrating a fourth example of a control method for the independent startup of the fuel cell system 100. Specifically, the time chart shows a fourth example of the change over time in the amount of stored electricity in the electricity storage device 200 during independent startup of the fuel cell system 100 and the flow of operations of the electricity supply system.

[0229] In this example, it is assumed that the waiting time TP1 of the prioritized load device with the first operating priority is zero (0), and the waiting time TP2 of the prioritized load device with the second operating priority is greater than zero (0). Also, in this example, it is assumed that the prioritized load devices with the third or lower operating priority are not set, or that the prioritized load devices with the third or lower operating priority do not start operating before the fuel cell module 110 is started up (specifically, the operable time TWx was set to zero (0) in the process of step S4047 in FIG. 14).

[0230] As shown in FIG. 16, in response to the establishment of the independent start-up condition of the fuel cell system 100, at time t41, the start-up of the fuel cell module 110 is started (step S406 in FIG. 13) and the start-up of the power conversion device 300 is started (step S410 in FIG. 13). Thereafter, at time t42, when the start-up of the power conversion device 300 is completed before the start-up of the fuel cell module 110, the supply of power from the fuel cell system 100 to the power distribution system 40 is started (step S412), and accordingly, the operation (operation) of the prioritized load device with the first operating priority is started (step S4144 in FIG. 15, which corresponds to the first operating priority). Thereafter, at time t43, which corresponds to the time when the waiting time TP2 has elapsed from the time t42 as the starting point, the operation (operation) of the prioritized load device with the second operating priority is started (step S4144 in FIG. 15, which corresponds to the second operating priority). Then, at time t44, when the start-up of the fuel cell module 110 is completed, power generation of the fuel cell module 110 begins (step S408 in FIG. 13), and accordingly, operation (running) of all the load devices 20 begins (step S416 in FIG. 13).

[0231] During the period from the start of the fuel cell module 110 and the power conversion device 300 to the completion of the start of the power conversion device 300, that is, the period from time t41 to time t42, power is supplied from the power storage device 200 only to the auxiliary device 120. Therefore, during this period, the amount of stored power in the power storage device 200 decreases relatively slowly in time series. At time t42, when the start of the power conversion device 300 is completed and the power conversion device 300 starts to output power to the power distribution system 40, the prioritized load device with the first operating priority starts operating. Therefore, during the period immediately after the start of the prioritized load device with the first operating priority, that is, the period from time t42 to time t43, power is supplied from the power storage device 200 to the auxiliary device 120 as well as to the prioritized load device with the first operating priority. Therefore, during this period, the amount of stored power in the power storage device 200 decreases faster than in the previous period (the period from time t41 to time t42). When the waiting time TP2 has elapsed from the output of power from the power conversion device 300 to the power distribution system 40 at time t43 as a starting point, during the period until the start-up of the fuel cell module 110 is completed, that is, during the period from time t43 to time t44, power is supplied from the power storage device 200 to the auxiliary machine 120 and the prioritized load device with the first operating priority, as well as to the prioritized load device with the second operating priority. Therefore, during this period, the amount of stored power in the power storage device 200 decreases more quickly than in the previous period (the period from time t42 to time t43). The period from time t42 to time t44 corresponds to the operable time TW1 of the prioritized load device with the first operating priority, and the period from time t43 to time t44 corresponds to the operable time TW2 of the prioritized load device with the second operating priority. Then, at time t44, when the fuel cell module 110 starts generating electricity, the decrease in the amount of stored electricity in the electricity storage device 200 stops, and after time t44, the amount of stored electricity (remaining stored electricity) in the electricity storage device 200 is maintained constant at a level slightly higher than the allowable lower limit.

[0232] In the period after time t44, the fuel cell system 100 may be controlled so that the generated power of the fuel cell module 110 is greater than the power consumed by the load device 20. In this case, the power storage device 200 is charged with the surplus power of the fuel cell module 110 (see the dashed line after time t44 in the figure).

[0233] In this way, in this example, when a power outage occurs in the AC power system 10, the control device 500 uses the remaining amount of stored power in the power storage device 200 to restart some of the load devices 20 with priority before the fuel cell module 110 completes its independent startup, in a power outage occurring in the AC power system 10. Specifically, in this example, the control device 500 operates only some of the load devices 20 (first and second priority load devices) with priority before the fuel cell module 110 completes its independent startup, in a power outage occurring in the AC power system 10. This allows the control device 500 to quickly restart some of the load devices 20 when a power outage occurs in the AC power system 10. Also, in this example, the control device 500 restarts some of the load devices 20 (for example, first priority load devices) with priority over other load devices before the fuel cell module 110 completes its independent startup, in a power outage occurring in the AC power system 10. This enables the control device 500 to more quickly restart some of the load devices 20 when a power outage occurs in the AC power system 10.

[0234] [Another example of a control method for autonomous startup of a fuel cell system] Another example of the control method for the independent startup of the fuel cell system 100 will be described.

[0235] The above-mentioned control methods (first to fourth examples) for the independent startup of the fuel cell system 100 may be modified or changed as appropriate. Hereinafter, examples in which the above-mentioned first to fourth examples of the control method are modified or changed may be referred to as "modified examples" for convenience.

[0236] For example, in a third example of the control method described above, when a power outage occurs in the AC power system 10, the control device 500 may use the power of the power storage device 200 to start up only a portion of two or more of the multiple fuel cell modules 110, and then start up the remaining fuel cell modules 110 using the generated power of the portion of the two or more fuel cell modules 110 that have already completed startup.

[0237] Furthermore, in the fourth example of the control method described above, similarly to the third example of the control method and its variations, when a power outage occurs in the AC power system 10, the control device 500 may use the power of the power storage device 200 to start up only some of the multiple fuel cell modules 110, and then start up the remaining fuel cell modules 110 using the power generated by some of the fuel cell modules 110 that have already completed startup.

[0238] In the first to third examples of the control method and their modified examples, the control device 500 may select the load device 20 to be operated using the power of the power storage device 200 before the independent start-up of the fuel cell module 110 is completed when a power outage occurs in the AC power system 10 from among the multiple load devices 20 that operate with power supply from the power distribution system 40. At this time, the selected load device 20 may be some of the multiple load devices 20, or all of the load devices 20. The control device 500 may automatically select some or all of the load devices 20 to be operated, or some or all of the load devices 20 to be operated may be selected in advance by input from the user. In the former case, for example, the control device 500 may select some or all of the load devices 20 to be operated in a manner that is variable based on various conditions such as the remaining amount of stored power in the power storage device 200 when the independent start-up condition is established. Specifically, the control device 500 may increase the number of load devices 20 to be operated using the power of the power storage device 200 as the remaining amount of stored power of the power storage device 200 increases when the independent startup condition is met. Also, the control device 500 may select load devices 20 that consume more power as the remaining amount of stored power of the power storage device 200 increases when the independent startup condition is met.

[0239] In the first to fourth examples of the control method and their modified examples, the control device 500 may control the remaining amount of stored electricity of the power storage device 200 in advance so that the remaining amount of stored electricity of the power storage device 200 is equal to or exceeds a predetermined standard before the fuel cell module 110 and the power conversion device 300 are started up when a power outage occurs in the AC power system 10. The predetermined standard is, for example, predefined according to the power consumption of the load device 20 to which the power storage device 200 supplies power before the fuel cell module 110 is started up when a power outage occurs in the AC power system 10. Specifically, the predetermined standard is set to be larger as the power consumption of the load device 20 increases. For example, the control device 500 charges the power storage device 200 with the power generated by the fuel cell module 110 so that the remaining amount of stored electricity of the power storage device 200 is equal to or exceeds the predetermined standard when the fuel cell module 110 and the power conversion device 300 are stopped from operating. Specifically, when the conditions for stopping the operation of the fuel cell system 100 and the power conversion device 300 are met, the control device 500 controls the output of the fuel cell module 110, charges the power storage device 200 until the remaining amount of stored electricity is equal to or exceeds a predetermined standard, and then stops the operation of the fuel cell system 100 and the power conversion device 300. In this way, when a power outage occurs in the AC power system 10, the control device 500 can ensure that the power storage device 200 can supply power to the load device 20 before the start-up of the fuel cell module 110 is completed. Therefore, when a power outage occurs in the AC power system 10, the control device 500 can reliably restart the load device 20 before the start-up of the fuel cell module 110 is completed.

[0240] Furthermore, in the first to fourth examples of the control method and their modified examples, when the independent start-up conditions of the fuel cell system 100 are met, the control device 500 may start up the fuel cell module 110 by operating only some of the auxiliaries 120 of the fuel cell system 100, unlike when the normal start-up conditions are met, and may start up the remaining auxiliaries 120 after start-up of the fuel cell module 110 is complete. In this way, when a power outage occurs in the AC power system 10, the control device 500 can reduce the amount of power required to start up the fuel cell module 110, and can ensure that the remaining amount of electricity in the power storage device 200 that can be supplied to operate the load device 20 is increased before start-up of the fuel cell module 110 is complete.

[0241] Among all the auxiliaries 120 of the fuel cell system 100, some of the auxiliaries 120 to be started during the independent start-up of the fuel cell system 100 include, for example, the auxiliaries 120 essential for the operation of the fuel cell module 110. The auxiliaries 120 essential for the operation of the fuel cell module 110 include, for example, the on-off valve 132, the pump 133, the compressor 144, the on-off valve 146, the on-off valve 152, and the like. In addition, among all the auxiliaries 120 of the fuel cell system 100, some of the auxiliaries 120 to be started during the independent start-up of the fuel cell system 100 do not include some or all of the cooling auxiliaries 120. This is because it is assumed that the temperature of the fuel cell module 110 is lowered to a relatively low state when the fuel cell system 100 is stopped. Furthermore, when a PEFC is adopted as the fuel cell cell 112, the time required for the start-up of the fuel cell module 110 is very short, so that the temperature of the fuel cell cell 112 is unlikely to become a problem within the start-up time of the fuel cell module 110. When the cooling auxiliary equipment 120 is included among the auxiliary equipment 120 to be started during the independent start-up of the fuel cell system 100 among all the auxiliary equipment 120 of the fuel cell system 100, the cooling auxiliary equipment 120 includes, for example, a pump 165. As a result, the cooling liquid in the cooling circuit CC2 circulates, and therefore the fuel cell 112 can be cooled to some extent through the cooling unit 114, although the performance is lower than when the cooling liquid in the cooling circuit CC1 circulates and the fan 162 is operating.

[0242] In the first to fourth examples of the control method and their modified examples, the control device 500 may start up the fuel cell module 110 and only some of the power conversion devices 300 when the independent start-up condition of the fuel cell system 100 is satisfied, assuming that there are multiple power conversion devices 300. In other words, the power conversion devices 300 to be started up in a period of the start-up process overlapping with the fuel cell module 110 when the independent start-up condition of the fuel cell system 100 is satisfied may be some of the power conversion devices 300. In this case, the part of the power conversion devices 300 to be started up is predefined so as to have a total capacity capable of outputting the power required for the load device 20 from the fuel cell system 100 and the power storage device 200. The required power is, for example, less than the maximum power consumption when the load device 20 can be supplied with power from the AC power system 10, and is predefined as a level of power required to operate the load device 20 with the minimum function during a power outage of the AC power system 10. As a result, the control device 500 can start up the multiple power conversion devices 300 in a distributed manner, on the premise that the power required for the load device 20 can be output from the power conversion device 300 using the power of the fuel cell module 110 and the power storage device 200 during a power outage in the AC power system 10. Then, the control device 500 starts up the remaining power conversion devices 300 after the start-up of some of the power conversion devices 300 is completed. In this case, the control device 500 may start up the remaining power conversion devices 300 simultaneously in one go, or may start up the remaining power conversion devices 300 in succession in multiple rounds. In addition, the remaining power conversion devices 300 may be started up at least after the start-up of the fuel cell module 110 that is started up first is completed, or may be started up at a predetermined timing according to the start-up completion of some of the power conversion devices 300, regardless of whether the start-up of the fuel cell module 110 is completed or not.

[0243] For example, assuming the third example of the control method described above or its modified example, when the independent startup conditions of the fuel cell system 100 are met, the control device 500 starts up some of the fuel cell modules 110 out of the multiple fuel cell modules 110, and also starts up some of the multiple power conversion devices 300 corresponding to some of the fuel cell modules 110 out of the multiple power conversion devices 300. Then, after startup of some of the fuel cell modules 110 and some of the power conversion devices 300 is complete, the control device 500 may start up the remaining fuel cell modules 110 and the remaining power conversion devices 300.

[0244] [Effect] The operation of the power supply system, the control device, and the control method according to the present embodiment will be described.

[0245] In a first aspect of this embodiment, the power supply system includes a fuel cell, a power storage device, a power conversion device, and a control device. The power supply system is, for example, the power supply system 30 described above. The fuel cell is, for example, the fuel cell module 110 described above. The power storage device is, for example, the power storage device 200 described above. The power conversion device is, for example, the power conversion device 300 described above. The control device is, for example, the control device 500 described above. Specifically, the power storage device is electrically connected to the fuel cell. Moreover, the power conversion device is electrically connected to the fuel cell and the power storage device, and is capable of outputting power supplied from at least one of the fuel cell and the power storage device to an external load device. The load device is, for example, the load device 20 described above. Moreover, the control device controls the fuel cell and the power conversion device. Then, when a power outage occurs in the power system that supplies power to the load device while the fuel cell and the power conversion device are not in operation, the control device starts up the fuel cell and also starts up the power conversion device using the power of the power storage device.

[0246] In the first aspect of this embodiment, the control device may be provided outside the power supply system.

[0247] In addition, in a first aspect of the present embodiment, there is provided a control method executed by a control device for a power supply system including a fuel cell, a power storage device electrically connected to the fuel cell, and a power conversion device electrically connected to the fuel cell and the power storage device and capable of outputting power supplied from at least one of the fuel cell and the power storage device to an external load device. Specifically, there is provided a control method in which, when a power grid supplying power to the load device experiences a power outage while the fuel cell and the power conversion device are out of operation, the control device starts up the fuel cell using power from the power storage device and also starts up the power conversion device.

[0248] This allows the control device to start up the fuel cell and the power conversion device in parallel when a power outage occurs in the power grid. In other words, the control device can overlap at least a portion of the time for starting up the fuel cell and the power conversion device when a power outage occurs in the power grid. Therefore, the control device can reduce the time it takes for both the fuel cell and the power conversion device to complete startup from a stopped state compared to, for example, when starting up the fuel cell and the power conversion device in series. Therefore, the control device can more quickly start supplying power from the fuel cell to the load device.

[0249] In addition, in a second aspect of this embodiment, based on the first aspect described above, when a power outage occurs in the power grid while the fuel cell and the power conversion device are stopped, the control device may start up the fuel cell and the power conversion device so that the timing of completion of startup of the power conversion device is after the timing of start of startup of the fuel cell and the timing of start of startup of the power conversion device is before the timing of completion of startup of the fuel cell.

[0250] As a result, when a power outage occurs in the power grid, the control device can overlap at least a portion of the start-up times of the fuel cell and the power conversion device, and can more quickly begin supplying power from the fuel cell to the load device.

[0251] In addition, in a third aspect of this embodiment, assuming the first or second aspect described above, when a power outage occurs in the power grid while the fuel cell and the power conversion device are stopped, the control device may start up the fuel cell and the power conversion device so that the timing of completion of start-up of the power conversion device is before the timing of completion of start-up of the fuel cell.

[0252] As a result, in the event of a power outage in the power grid, the control device can complete the startup of the power conversion device before the startup of the fuel cell is completed, and can start supplying power from the storage device to the load device via the power conversion device. Therefore, in the event of a power outage in the power grid, the control device can more quickly restart the load device.

[0253] In addition, in a fourth aspect of this embodiment, based on the third aspect described above, when the power grid is interrupted while the fuel cell and the power conversion device are stopped, the control device may start up the fuel cell and the power conversion device so that the timing of the start-up completion of the power conversion device is before the timing of the start-up completion of the fuel cell, and when the start-up of the power conversion device is completed, wait until a predetermined timing before the start-up completion of the fuel cell and start the operation of the load device. The predetermined timing is, for example, the timing when a waiting time TP has elapsed from the start-up completion of the above-mentioned power conversion device 300.

[0254] This enables the control device to prevent a situation in which, in the event of a power outage in the power grid, the power that can be supplied from the storage device to the load device runs out before the fuel cell has completed startup, making it impossible to supply power to the load device.

[0255] In a fifth aspect of this embodiment, based on the third or fourth aspect described above, when the power grid experiences a power outage while the fuel cell and the power conversion device are out of operation, the control device may wait until a predetermined timing after the start of the fuel cell start-up before starting up the power conversion device, and may start up the fuel cell and the power conversion device so that the start-up of the power conversion device is completed before the start-up of the fuel cell. The predetermined timing is, for example, the timing when a waiting time TP has elapsed from the start of the start-up of the fuel cell module 110 described above.

[0256] This enables the control device to prevent a situation in which, in the event of a power outage in the power grid, the power that can be supplied from the storage device to the load device runs out before the fuel cell completes startup, making it impossible to supply power to the load device.

[0257] Furthermore, in a sixth aspect of this embodiment, assuming the fourth or fifth aspect described above, the specified timing may be determined based on the remaining amount of stored power in the storage device, the amount of power required from the start of startup of the fuel cell to the completion of startup, and the power consumption of the load device.

[0258] This allows the control device to appropriately determine the predetermined timing so that, in the event of a power outage in the power grid, power supply from the power storage device to the load device can be continued until the start-up of the fuel cell is completed.

[0259] In addition, in a seventh aspect of this embodiment, assuming any one of the third to sixth aspects described above, there may be a plurality of fuel cells. When the power grid experiences a power outage while the fuel cells and the power conversion device are out of operation, the control device may start up some of the fuel cells and start up the power conversion device, and after the start-up of the some of the fuel cells is complete, start up the remaining fuel cells. The some of the fuel cells may be, for example, the specific fuel cell module 110 described above.

[0260] As a result, when a power outage occurs in the power grid, the control device can start up some of the fuel cells in advance, and use the power from some of the fuel cells that have already completed startup to cover the power required to start up the remaining fuel cells. Therefore, the control device can reduce the amount of power output from the power storage device for starting up the multiple fuel cells. Therefore, when a power outage occurs in the power grid, the control device can operate the load device for a longer period of time using power supplied from the power storage device before the multiple fuel cells have completed startup.

[0261] In an eighth aspect of the present embodiment, on the premise of any one of the first to seventh aspects described above, there may be a plurality of the load devices. When a power outage occurs in the power grid while the fuel cell and the power conversion device are out of operation, the control device may start up the fuel cell and the power conversion device, and output the power supplied from the power storage device from the power conversion device to the load device after the power conversion device has been started up and before the fuel cell has been started up, thereby preferentially operating some of the load devices among the plurality of load devices.

[0262] As a result, in the event of a power outage in the power grid, the control device can use limited power from the storage device to operate some of the multiple load devices on a priority basis before the fuel cell has completed startup.

[0263] In addition, in a ninth aspect of the present embodiment, on the premise of the eighth aspect described above, a priority may be predefined for each of the plurality of load devices. The priority may be, for example, the above-mentioned operation priority order. When a power outage occurs in the power grid while the fuel cell and the power conversion device are out of operation, the control device may start up the fuel cell and the power conversion device, and output the power supplied from the power storage device from the power conversion device to the load device after the power conversion device has been started up and before the fuel cell has been started up, thereby preferentially operating some of the load devices having higher priorities among the plurality of load devices.

[0264] As a result, in the event of a power outage in the power grid, the control device can use the limited power of the storage device to operate some of the multiple load devices on a priority basis before the fuel cell has completed startup.

[0265] In addition, in a tenth aspect of the present embodiment, on the premise of the eighth or ninth aspect described above, the plurality of load devices may include a first load device and a second load device. The first load device and the second load device are, for example, a priority load device with a first operation priority and a priority load device with a second operation priority. When the power grid experiences a power outage while the fuel cell and the power conversion device are out of operation, the control device may start up the fuel cell and the power conversion device, and output the power supplied from the storage device from the power conversion device to the load device after the power conversion device has been started up and before the fuel cell has been started up, thereby starting up the first load device and the second load device at different timings.

[0266] As a result, when a power outage occurs in the power grid, the control device can use the limited power of the storage device to prioritize starting up either the first load device or the second load device before the fuel cell has completed startup.

[0267] Furthermore, in an eleventh aspect of this embodiment, assuming any one of the eighth to tenth aspects described above, when a power outage occurs in the power system while the fuel cell and the power conversion device are stopped, the control device may start up the fuel cell and also start up the power conversion device, and between the completion of startup of the power conversion device and the completion of startup of the fuel cell, the control device may operate only some of the multiple load devices by outputting the power supplied from the storage device from the power conversion device to the load device.

[0268] As a result, in the event of a power outage in the power grid, the control device can use the limited power from the storage device to prioritize restarting only some of the multiple load devices before the fuel cell has completed startup.

[0269] In addition, in a twelfth aspect of the present embodiment, on the premise of any one of the third to eleventh aspects described above, the load device may be multiple. When a power outage occurs in the power grid while the fuel cell and the power conversion device are out of operation, the control device may start up the fuel cell and the power conversion device, and output the power supplied from the power storage device from the power conversion device to the load device after the power conversion device has been started up and before the fuel cell has been started up, thereby operating some or all of the load devices selected according to the remaining amount of power stored in the power storage device from among the multiple load devices.

[0270] As a result, in the event of a power outage in the power grid, the control device can restart some or all of the load devices so that power can be continuously supplied from the power storage device to the load devices before the start-up of the fuel cell is completed.

[0271] In a thirteenth aspect of this embodiment, on the premise of any one of the third to twelfth aspects described above, the power supply system may include a plurality of electrically operated auxiliaries of the fuel cell. The auxiliaries are, for example, the above-mentioned auxiliaries 120. When the power grid experiences a power outage while the fuel cell and the power conversion device are out of operation, the control device may start up the fuel cell by operating only some of the auxiliaries using the power of the power storage device.

[0272] This allows the control device to reduce the amount of power required from the start of startup to the completion of startup of the fuel cell when a power outage occurs in the power grid. Therefore, the control device can ensure that a larger amount of power can be supplied from the power storage device to the load device before the startup of the fuel cell is completed when a power outage occurs in the power grid. Therefore, the control device can operate the load device for a longer period of time using power supplied from the power storage device before the startup of the multiple fuel cells is completed when a power outage occurs in the power grid.

[0273] In addition, in a fourteenth aspect of this embodiment, assuming any one of the third to thirteenth aspects described above, the control device may charge the power storage device using power from the fuel cell so that the remaining amount of power stored in the power storage device when the fuel cell and the power conversion device are stopped is relatively large with respect to a predetermined standard.

[0274] This allows the control device to adjust the remaining charge of the power storage device in advance so that the power storage device can have a relatively large remaining charge when a power outage occurs in the power grid. Therefore, when a power outage occurs in the power grid, the control device can operate the load device for a longer period of time using the power supplied from the power storage device before the start-up of the multiple fuel cells is completed.

[0275] In addition, in a fifteenth aspect of the present embodiment, on the premise of the above-mentioned fourteenth aspect, the predetermined standard may be defined based on power consumption of the load device.

[0276] This allows the control device to adjust in advance the remaining amount of stored electricity in the electricity storage device so that the electricity storage device can ensure a remaining amount of stored electricity according to the power consumption of the load device operated by the power supply from the electricity storage device.

[0277] In addition, in a sixteenth aspect of the present embodiment, on the premise of any one of the first to fifteenth aspects described above, there may be a plurality of the power conversion devices. Then, when a power outage occurs in the power grid while the fuel cell and the power conversion devices are out of operation, the control device may start up the fuel cell using the power of the power storage device, start up only some of the power conversion devices among the plurality of the power conversion devices, and start up the remaining power conversion devices after the start-up of some of the power conversion devices is completed.

[0278] As a result, the control device can start up multiple power conversion devices in a chronological order in accordance with the start-up of the fuel cell, for example, under the assumption that some power conversion devices can supply the necessary power from a fuel cell or a power storage device to a load device.

[0279] Although the embodiments have been described in detail above, the present disclosure is not limited to such specific embodiments, and various modifications and variations are possible within the scope of the gist described in the claims. [Explanation of symbols]

[0280] 1. Power System 10 AC power system 20 Load device 30 Power Supply System 40 Power distribution system 100 Fuel Cell System 110 Fuel Cell Module 112 Fuel Cell 114 Cooling section 116 Converter device 120 Auxiliary Equipment 130 Fuel supply section 131 Hydrogen Source 132 On-off valve 133 Pump 134 Gas-liquid separator 140 Air supply section 142 Air cleaner 144 Compressor 146 On-off valve 150 Discharge section 152 On-off valve 154 Mixer 156 Gas-liquid separator 160 Cooling section 161 Cooler 162 Fans 163 Pump 164 Heat exchanger 165 Pump 166 Ion Exchanger 200 Electricity storage device 250 DC link section 300 Power Converter 400 Transformer 500 Control device

Claims

1. A fuel cell; an electricity storage device electrically connected to the fuel cell; a power conversion device having one end electrically connected to the fuel cell and the power storage device and the other end electrically connected to an external load device, the power conversion device being capable of outputting power supplied from at least one of the fuel cell and the power storage device to the load device; a control device for controlling the fuel cell and the power conversion device, when a power grid that supplies power to the load device experiences a power outage while the fuel cell and the power conversion device are out of operation, the control device starts up the fuel cell and the power conversion device using power from the power storage device. Power supply system.

2. when a power outage occurs in the power grid while the fuel cell and the power conversion device are out of operation, the control device starts up the fuel cell and the power conversion device such that a timing for completing the start-up of the power conversion device is after a timing for starting the start-up of the fuel cell and a timing for starting the start-up of the power conversion device is before a timing for completing the start-up of the fuel cell. The power supply system according to claim 1 .

3. when a power outage occurs in the power grid while the fuel cell and the power conversion device are out of operation, the control device starts up the fuel cell and the power conversion device so that a timing at which the power conversion device completes start-up is before a timing at which the fuel cell completes start-up. The power supply system according to claim 2 .

4. When the power grid experiences a power outage while the fuel cell and the power conversion device are not operating, the control device starts up the fuel cell and the power conversion device so that the timing of completion of startup of the power conversion device is before the timing of completion of startup of the fuel cell, and when startup of the power conversion device is completed, waits until a predetermined timing before completion of startup of the fuel cell, and starts operation of the load device. The power supply system according to claim 3 .

5. When a power outage occurs in the power grid while the fuel cell and the power conversion device are not operating, the control device waits until a predetermined timing after the start of startup of the fuel cell before starting startup of the power conversion device, and starts up the fuel cell and the power conversion device so that the start-up completion timing of the power conversion device is before the start-up completion timing of the fuel cell. The power supply system according to claim 3 .

6. The predetermined timing is determined based on a remaining amount of electricity stored in the electricity storage device, an amount of electricity required from the start of startup of the fuel cell to the completion of startup, and a power consumption of the load device. The power supply system according to claim 4 or 5.

7. The fuel cell is a plurality of fuel cells, When a power outage occurs in the power grid while the fuel cells and the power conversion device are not in operation, the control device starts up some of the fuel cells and starts up the power conversion device, and after the start-up of the some of the fuel cells is completed, starts up the remaining fuel cells. The power supply system according to any one of claims 3 to 5.

8. The load device is provided in a plurality of types. When a power outage occurs in the power grid while the fuel cell and the power conversion device are not operating, the control device starts up the fuel cell and also starts up the power conversion device, and during the period between the completion of the start-up of the power conversion device and the completion of the start-up of the fuel cell, the control device outputs the power supplied from the power storage device from the power conversion device to the load device, thereby preferentially operating some of the multiple load devices. The power supply system according to any one of claims 3 to 5.

9. A priority is predefined for each of the plurality of load devices; When a power outage occurs in the power grid while the fuel cell and the power conversion device are not operating, the control device starts up the fuel cell and also starts up the power conversion device, and during the period between the completion of the start-up of the power conversion device and the completion of the start-up of the fuel cell, the control device outputs the power supplied from the power storage device from the power conversion device to the load device, thereby preferentially operating some of the load devices having higher priorities among the plurality of load devices. The power supply system according to claim 8.

10. the plurality of load devices include a first load device and a second load device; When a power outage occurs in the power grid while the fuel cell and the power conversion device are not operating, the control device starts up the fuel cell and also starts up the power conversion device, and outputs the power supplied from the power storage device from the power conversion device to the load device after the start-up of the power conversion device is completed and before the start-up of the fuel cell is completed, thereby starting the first load device and the second load device at different times. The power supply system according to claim 8.

11. When a power outage occurs in the power grid while the fuel cell and the power conversion device are not operating, the control device starts up the fuel cell and also starts up the power conversion device, and during the period between the completion of start-up of the power conversion device and the completion of start-up of the fuel cell, the control device causes the power conversion device to output the power supplied from the power storage device to the load device, thereby operating only some of the multiple load devices. The power supply system according to claim 8.

12. The load device is provided in a plurality of types. When a power outage occurs in the power grid while the fuel cell and the power conversion device are not operating, the control device starts up the fuel cell and also starts up the power conversion device, and during the period between the completion of start-up of the power conversion device and the completion of start-up of the fuel cell, the control device causes the power conversion device to output the power supplied from the power storage device to the load device, thereby operating some or all of the load devices selected from the plurality of load devices according to the remaining amount of power stored in the power storage device. The power supply system according to any one of claims 3 to 5.

13. a plurality of fuel cell accessories that are electrically powered; When the power grid experiences a power outage while the fuel cell and the power conversion device are not in operation, the control device starts up the fuel cell by operating only some of the multiple auxiliaries using power from the power storage device. The power supply system according to any one of claims 3 to 5.

14. the control device charges the power storage device using the power of the fuel cell so that a remaining amount of power stored in the power storage device becomes large relative to a predetermined standard when the fuel cell and the power conversion device are stopped from operating. The power supply system according to any one of claims 3 to 5.

15. The predetermined standard is defined based on the power consumption of the load device. The power supply system according to claim 14.

16. There are a plurality of the power conversion devices, When a power outage occurs in the power grid while the fuel cell and the power conversion devices are not operating, the control device starts up the fuel cell using power from the power storage device, and starts up only some of the power conversion devices among the plurality of power conversion devices, and starts up the remaining power conversion devices after the start-up of some of the power conversion devices is completed. The power supply system according to any one of claims 1 to 5.

17. A power supply system including a fuel cell, a power storage device electrically connected to the fuel cell, and a power conversion device having one end electrically connected to the fuel cell and the power storage device and another end electrically connected to an external load device, the power conversion device being capable of outputting power supplied from at least one of the fuel cell and the power storage device to the load device, When a power grid that supplies power to the load device experiences a power outage while the fuel cell and the power conversion device are out of operation, the fuel cell is started up using power from the power storage device, and the power conversion device is also started up. Control device.

18. A control method executed by a control device for a power supply system including a fuel cell, a power storage device electrically connected to the fuel cell, and a power conversion device having one end electrically connected to the fuel cell and the power storage device and another end electrically connected to an external load device, the power conversion device being capable of outputting power supplied from at least one of the fuel cell and the power storage device to the load device, the method comprising: When a power grid that supplies power to the load device experiences a power outage while the fuel cell and the power conversion device are out of operation, the fuel cell is started up using power from the power storage device, and the power conversion device is also started up. Control methods.

Images