JP7477031B1 - Power supply system, control device, and control method - Google Patents

Abstract

A technique is provided that makes it possible to reduce the capacity of a power storage device required to start up a fuel cell using the power of the power storage device.
[Solution] A power supply system 30 according to one embodiment comprises a fuel cell module 110, a power storage device 200 electrically connected to the fuel cell module 110, a number of fuel cell accessories 120 that operate electrically, and a control device 500 that controls the startup of the fuel cell module 110, and the control device 500 starts up the fuel cell module 110 by operating only some of the multiple accessories 120 using power from the power storage device 200.
[Selected figure] Figure 5

Description

This disclosure relates to power supply systems, etc.

For example, in a power supply system including a fuel cell and a power storage device (e.g., a storage battery or a capacitor), the fuel cell may be started using the power of the power storage device (see Patent Documents 1 and 2).

JP 2016-127777 A JP 2017-126441 A

However, in order to start up a fuel cell using the power of a power storage device, the capacity of the power storage device must be large enough to cover the operation of the fuel cell's auxiliary equipment from the start to completion of fuel cell startup. Therefore, depending on, for example, the specifications of the auxiliary equipment and the number of fuel cells included in the power supply system, the required capacity may be relatively large, which may result in increased costs.

In view of the above problems, the objective is to provide a technology that can reduce the capacity of the power storage device required to start a fuel cell using the power of the power storage device.

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;
a plurality of electrically powered auxiliary components of the fuel cell;
A control device that controls the start-up of the fuel cell;
a second power storage device provided separately from the first power storage device and supplying power to the control device;
the control device starts up the fuel cell by operating only a portion of the plurality of auxiliary machines using the power of the power storage device;
A power supply system is provided.

In another embodiment of the present disclosure,
A control device for controlling start-up of a fuel cell in a power supply system including a fuel cell, a power storage device electrically connected to the fuel cell, a plurality of electrically operated auxiliary devices of the fuel cell, and a second power storage device provided separately from the first power storage device, the control device comprising:
Electric power is supplied from the second power storage device,
starting up the fuel cell by operating only some of the plurality of auxiliary machines using the power of the power storage device;
A controller is provided.

In still another embodiment of the present disclosure,
A control method for a power supply system including a fuel cell, a power storage device electrically connected to the fuel cell, a plurality of electrically operated auxiliary devices of the fuel cell, and a second power storage device provided separately from the first power storage device, the method comprising: a control device to which power is supplied from the second power storage device controls start-up of the fuel cell, the control method comprising the steps of:
the control device starts up the fuel cell by operating only a portion of the plurality of auxiliary machines using the power of the power storage device;
A control method is provided.

According to the above-described embodiment, it is possible to reduce the capacity of the power storage device required to start the fuel cell using the power of the power storage device.

FIG. 1 is a diagram illustrating a configuration of a first example of a power system. FIG. 11 is a diagram illustrating a configuration of a second example of a power system. FIG. 13 is a diagram illustrating a configuration of a third example of a power system. FIG. 1 is a diagram showing a configuration of an example of a fuel cell system. 4 is a flowchart illustrating a first example of a control method for independent startup of a fuel cell system. 6 is a time chart illustrating a second example of a control method for independent startup of a fuel cell system. 10 is a flowchart illustrating a second example of a control method for independent startup of a fuel cell system. 10 is a time chart illustrating a third example of a control method for independent startup of a fuel cell system. 13 is a flowchart illustrating a third example (part 1) of a control method for independent startup of a fuel cell system. 13 is a flowchart illustrating a third example (part 2) of a control method for independent startup of a fuel cell system. 13 is a time chart illustrating a fourth example of a control method for independent startup of a fuel cell system. 10 is a flowchart illustrating a fourth example of a control method for independent startup of a fuel cell system. 13 is a time chart illustrating a fifth example of a control method for independent startup of a fuel cell system. 10 is a flowchart illustrating a fifth example of a control method for independent startup of a fuel cell system. 13 is a flowchart illustrating a sixth example of a control method for the independent startup of a fuel cell system. 13 is a flowchart illustrating a seventh example of a control method for the independent startup of a fuel cell system. FIG. 13 is a diagram illustrating a configuration of a fourth example of a power system.

The following describes the embodiment with reference to the drawings.

[Configurations of First to Third Examples of Power System]
The configurations of first to third examples of a power system 1 according to the present embodiment will be described with reference to FIGS. 1 to 3. FIG.

Figure 1 is a diagram showing a configuration of a first example of the power system 1. Figure 2 is a diagram showing a configuration of a second example of the power system 1. Figure 3 is a diagram showing a configuration of a third example of the power system 1.

In FIG. 2, the configurations of the multiple fuel cell systems 100 are all the same, so the fuel cell module 110 and the auxiliary equipment 120 are drawn for only one of the multiple fuel cell systems 100. In FIG. 3, the configurations of the multiple power supply systems 30 are the same as those in FIG. 1 or 2, so the illustration of each component is omitted.

As shown in Figures 1 to 3, the power system 1 includes an AC power system 10, a load device 20, and a power supply system 30.

The power system 1 can connect the power supply system 30 to the AC power system 10 through the power distribution system 40, and supply the power output from the power supply system 30 to the demand side connected to the AC power system 10. The power system 1 can also 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. The power system 1 can also supply power from the power supply system 30 to the load device 20 through the power distribution system 40.

The AC power system 10 transmits power output from the power supply system 30 and other power generation facilities to the demand side by AC. The AC power system 10 transmits three-phase AC by a three-phase three-wire system.

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 is, for example, a production facility installed in the same factory as the power supply system 30.

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.

As shown in Figures 1 and 2, one power supply system 30 is provided for one power distribution system 40. Also, as shown in Figure 3, multiple power supply systems 30 may be connected in parallel to one power distribution system 40.

As shown in Figures 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.

The fuel cell system 100 supplies power to the AC power system 10 through 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.

For example, as shown in FIG. 1, one fuel cell system 100 is provided. Also, as shown in FIG. 2, multiple fuel cell systems 100 may be provided. In this case, the multiple fuel cell systems 100 are connected in parallel to the DC link unit 250.

The fuel cell system 100 includes a fuel cell module 110 that receives a fuel supply and generates electricity, and auxiliary equipment 120 for operating the fuel cell module 110. The auxiliary equipment 120 is operated by AC supplied from the power distribution system 40.

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 fixed 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.

The storage device 200 may be one or more as shown in Figures 1 and 2. In the latter case, the multiple storage devices 200 may be connected in series or in parallel to the DC link unit 250, or a direct connection of two or more storage devices 200 may be connected in parallel to the DC link unit 250.

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) that includes an inverter circuit that converts the DC into three-phase AC of a predetermined voltage and frequency.

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

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, multiple combinations of the power conversion device 300 and the transformer 400 may be provided in parallel. Also, when the power supply system 30 includes multiple fuel cell systems 100, one combination of the power conversion device 300 and the transformer 400 may be provided, or multiple combinations may be provided in parallel as shown in FIG. 2. As shown in FIG. 2, when multiple 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.

The control device 500 controls the operation of the power supply system 30.

For example, the control device 500 controls the fuel cell system 100 and the power conversion device 300 according to the power requested by the demand side connected to the AC power system 10 (hereinafter simply referred to as "demand side request"), 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 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.

The control device 500 may also perform processing (start-up processing) to start the fuel cell system 100 in a stopped state, and processing (stop processing) to stop the fuel cell system 100 in an operating state. Starting the fuel cell system 100 means starting the auxiliary equipment 120 of the fuel cell system 100 in a stopped state of the fuel cell system 100, and starting 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.

The functions of the control device 500 are realized by any hardware or any combination of hardware and software. For example, the control device 500 is mainly composed of a computer including a CPU (Central Processing Unit), a memory device, an auxiliary storage device, and an interface device. In this case, the control device 500 can realize various functions by, for example, loading a program installed in the auxiliary storage device into the memory device and executing it on the CPU. The control device 500 is, for example, a PLC (Programmable Logic Controller).

[Configuration of fuel cell system]
Next, the configuration of the fuel cell system 100 according to this embodiment will be described with reference to FIG.

Figure 4 shows an example of the configuration of a fuel cell system 100.

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

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

The fuel cell 112 generates electricity by chemically reacting hydrogen, which is supplied as fuel from the fuel supply unit 130, with oxygen in the air taken in from the air supply 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 multiple single cells are stacked.

The 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 formed of a porous material. Each of the pair of electrodes has a catalyst layer mainly composed of carbon powder that supports a platinum-based metal catalyst (electrode catalyst), and a gas diffusion layer that is both breathable and electronically conductive. Furthermore, the single cell has a pair of separators that sandwich the membrane electrode assembly (MEA) from both sides.

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

The water and exhaust gas remaining after the hydrogen has chemically reacted with oxygen in the air are discharged from the fuel cell 112 to the exhaust section 150.

The cooling unit 114 cools the fuel cell 112. Specifically, a cooling liquid flows through the inside of the cooling unit 114. The cooling unit 114 can cool the fuel cell 112 by exchanging heat between the fuel cell 112 and the cooling liquid.

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.

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.

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

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 that 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 that hydrogen is being 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 auxiliary devices 120.

The pump 133 is provided in the circulation path L2 that returns excess hydrogen gas discharged from the fuel cell 112 to the supply path L1. The circulation path L2 joins 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 auxiliary machines 120.

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

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

The air cleaner 142 removes dust, impurities, etc. from the air taken in from one end of the air supply path L3.

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 auxiliary machines 120.

The on-off valve 146 is a valve that opens and closes the air supply path L3. The on-off valve 146 is provided between the compressor 144 and the fuel cell 112 in the air supply path L3. 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. When the on-off valve 146 is in an open state, 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 devices 120.

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

The on-off valve 152 is a valve that opens and closes the exhaust path L4. The on-off valve 152 is provided at the most upstream part of the exhaust path L4. When the on-off valve 152 is in a closed state, this indicates that 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 that the water and exhaust gas can be discharged from the fuel cell 112 to the outside through the exhaust 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 auxiliary devices 120.

The mixer 154 merges the water separated by the gas-liquid separator 134 into the discharge path L4.

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.

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

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

The cooler 161 cools the coolant in the cooling circuit CC1. As a result, 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.

The fan 162 generates an air flow that passes through the cooler 161. This can promote the 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 auxiliary machines 120.

The pump 163 is provided in the cooling circuit CC1 and circulates the cooling liquid 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 auxiliary machines 120.

The heat exchanger 164 exchanges heat between the coolant in the cooling circuit CC1, which includes the cooler 161, and the coolant in the cooling circuit CC2, which includes the cooling section 114, to cool 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 section 114, thereby cooling the fuel cell 112.

The pump 165 is provided in the cooling circuit CC2 and circulates the cooling liquid 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 auxiliary machines 120.

The ion exchanger 166 is provided in the cooling circuit CC2 and removes ionic impurities from the cooling liquid in the cooling circuit CC2. This ensures the insulation of the cooling liquid.

Hereinafter, the auxiliary equipment 120 included in the cooling section 160 may be referred to as "cooling auxiliary equipment 120."

[Control method for normal startup of fuel cell system]
Next, still with reference to FIGS. 1 to 4, a control method for normal startup of the fuel cell system 100 (first to third examples) will be described.

Normal startup of the fuel cell system 100 means startup of the fuel cell system 100 in a state in which power can be supplied from the AC power system 10 to the fuel cell system 100 via the power distribution system 40.

When the conditions for performing normal startup of the fuel cell system 100 (normal startup conditions) are met while the fuel cell system 100 is in a stopped state, the control device 500 operates the auxiliary equipment 120 using power supplied from the AC power grid 10 to start the fuel cell system 100.

Normal startup conditions are, for example, when the fuel cell system 100 is stopped, the AC power grid 10 is in a state where it can normally supply power, and a startup command for the fuel cell system 100 is input.

The start 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 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 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 cloud server for management installed in a management center located in a different location from the facility where the power supply system 30 is installed. The start command for the fuel cell system 100 may also be automatically generated according to a predetermined rule. For example, the start 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 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.

The control device 500 performs normal startup of the fuel cell system 100 by starting up all of the auxiliary devices 120 of the fuel cell system 100 using power supplied from the AC power system 10 via the power distribution system 40.

[First Example of Control Method for Self-Startup of Fuel Cell System]
Next, a first example of a control method for the independent 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.

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 through the power distribution system 40, i.e., startup of the fuel cell system 100 without an external power supply during a power outage in the AC power system 10.

When the AC power system 10 is in a power outage state, the control device 500 operates using power discharged from the power storage device 200 through the power conversion device 300 and the transformer 400.

<Overview of control method>
In this example, when the conditions for implementing independent startup of the fuel cell system 100 (independent startup conditions) are met while the fuel cell system 100 is in a stopped state, the control device 500 operates the auxiliary device 120 using power supplied from the power storage device 200 to start the fuel cell system 100. Specifically, the control device 500 outputs a startup command to the auxiliary device 120 of the fuel cell system 100, and controls the power conversion device 300 to discharge power for operating the auxiliary device 120 from the power storage device 200 via the power conversion device 300 to the power distribution system 40.

The independent startup conditions are, for example, that the fuel cell system 100 is stopped, that the AC power system 10 is in 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 and signals input by communication from a management device that manages the AC power system 10.

When the fuel cell system 100 is started up independently, the control device 500 starts only some of the auxiliary devices 120 of the fuel cell system 100, and starts the fuel cell module 110 by operating these auxiliary devices 120. Then, when the start-up of the fuel cell system 100, i.e., the start-up of the fuel cell module 110, is completed, the control device 500 controls the fuel cell system 100 and the power conversion device 300 to supply the power of the operating fuel cell module 110 to the auxiliary devices 120 through the power distribution system 40 and start the remaining auxiliary devices 120. This makes it possible to reduce the amount of power that the storage device 200 should output in order to start up the fuel cell system 100 independently. Therefore, when the fuel cell system 100 is started up independently, the capacity of the storage device 200 can be reduced compared to when all the auxiliary devices 120 are operated, and as a result, the cost of the storage device 200 can be reduced.

Hereinafter, for convenience, among all the auxiliary devices 120 of the fuel cell system 100, a portion of the auxiliary devices 120 to be started when the fuel cell system 100 starts up independently may be referred to as the "minimum auxiliary devices 120."

The minimum auxiliary equipment 120 includes, for example, the auxiliary equipment 120 required for the operation of the fuel cell module 110. The auxiliary equipment 120 required for the operation of the fuel cell module 110 includes, for example, the on-off valve 132, the pump 133, the compressor 144, the on-off valve 146, the on-off valve 152, etc. The minimum auxiliary equipment 120 does not include some or all of the cooling auxiliary equipment 120. This is because it is assumed that the temperature of the fuel cell module 110 drops to a relatively low state when the fuel cell system 100 is stopped. Furthermore, when a PEFC is used as the fuel cell cell 112, the time required to start 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 time required to start the fuel cell module 110. If the minimum auxiliary equipment 120 does not include some of the cooling auxiliary equipment 120, the remaining cooling auxiliary equipment 120 included in the minimum auxiliary equipment 120 includes, for example, the pump 165. As a result, the cooling liquid in the cooling circuit CC2 circulates, and although performance is reduced compared to when the cooling liquid in the cooling circuit CC1 circulates and the fan 162 is operating, the fuel cell 112 can be cooled to a certain extent through the cooling section 114.

As shown in FIG. 2, when the power supply system 30 includes multiple fuel cell systems 100 and two or more fuel cell systems 100 are subject to independent startup, only the minimum number of auxiliary devices 120 are started when each fuel cell system 100 is started independently. The same applies to the first to fourth examples described below.

<Control flow>
FIG. 5 is a flow chart that illustrates a first example of a control method for the independent startup of the fuel cell system 100. As shown in FIG.

This flowchart is executed, for example, when the conditions for independent startup of the fuel cell system 100 are met. The same may be true for the flowcharts in Figures 7, 9, 10, 12, and 15 described below.

In step S102, the control device 500 controls the power conversion device 300 to discharge the power storage device 200 to the power distribution system 40, and uses the power to start up the minimum number of auxiliary devices 120, thereby starting the independent startup of the fuel cell system 100.

When processing of step S102 is completed, the control device 500 proceeds to step S104.

In step S104, the control device 500 determines whether or not the start-up of the fuel cell system 100, i.e., the start-up of the fuel cell module 110, has been completed. If the start-up of the fuel cell system 100 has been completed, the control device 500 proceeds to step S106, and if it has not been completed, the control device 500 repeats the processing of this step until it is completed.

In step S106, the control device 500 controls the fuel cell system 100 and the power conversion device 300 to supply power from the fuel cell module 110 to the auxiliary devices 120 through the power distribution system 40, thereby starting up the remaining auxiliary devices 120. As a result, after starting up the fuel cell system 100, the control device 500 can transition the fuel cell system 100 from a state in which only a minimum number of auxiliary devices 120 are operating to a state in which all auxiliary devices 120 are operating.

When processing of step S106 is completed, the control device 500 ends the processing of this flowchart.

[Second Example of Control Method for Self-Startup of Fuel Cell System]
Next, a second example of a control method for the independent startup of the fuel cell system 100 (first to third examples) will be described with reference to FIGS. 6 and 7 in addition to FIGS. 1 to 4.

The following description will focus on the differences from the first example of the control method described above, and may omit descriptions of content that is the same as or corresponds to the first example of the control method described above.

<Overview of control method>
Fig. 6 is a time chart illustrating a second example of a control method for the independent startup of the fuel cell system 100. Specifically, Fig. 6 is a time chart showing the change over time in temperature (cell temperature) T of the fuel cell 112 during independent startup of the fuel cell system 100.

As shown in FIG. 6, in this example, at time t11, the control device 500 starts the independent startup of the fuel cell system 100 when the independent startup conditions are met. At this time, as in the first example described above, the control device 500 starts only the minimum number of accessories 120 out of all accessories 120, and does not start some or all of the cooling accessories 120 that are not included in the minimum number of accessories 120.

After time t11, the cell temperature T increases over time, and at time t12, it transitions to a state that is relatively high relative to the predetermined threshold Tth1.

Here, in this example, the control device 500 additionally starts the remaining cooling accessories 120 that are not in operation. For example, the control device 500 can grasp the cell temperature T by acquiring a detection signal from a temperature sensor built into the fuel cell 112 through communication with the fuel cell system 100. As a result, after time t12, the cell temperature T transitions from an increasing state to a state in which it gradually decreases. Therefore, the control device 500 can prevent a situation in which the fuel cell module 110 becomes overheated due to an increase in the cell temperature T.

After that, at time t13, the startup of the fuel cell module 110 is completed. Then, in response to the completion of startup of the fuel cell system 100, the control device 500 starts up the remaining auxiliary devices 120, including the cooling auxiliary devices 120 that are not in operation, and transitions to a state in which all auxiliary devices 120 are in operation.

In this way, in this example, when the cell temperature T becomes relatively high with respect to the threshold value Tth1 between the start and completion of the independent startup of the fuel cell system 100, the control device 500 can transition to a state in which all cooling accessories 120 are in operation. Therefore, the control device 500 can suppress the amount of power used during the independent startup of the fuel cell system 100 while suppressing a situation in which the fuel cell module 110 overheats.

<Control flow>
FIG. 7 is a flow chart that illustrates a second example of a control method for the independent startup of the fuel cell system 100. In FIG.

As shown in FIG. 7, step S202 is the same as step S102 in FIG. 5, so its explanation is omitted.

When processing in step S202 is completed, proceed to step S204.

In step S204, the control device 500 determines whether the cell temperature T of at least one of the fuel cell cells 112 of the fuel cell module 110 is equal to or greater than the threshold value Tth1. If the cell temperature T of at least one of the fuel cell cells 112 of the fuel cell module 110 is equal to or greater than the threshold value Tth1, the control device 500 proceeds to step S208; otherwise, the control device 500 proceeds to step S206.

In step S206, the control device 500 performs the same determination as in step S104 in FIG. 5. If the start-up of the fuel cell system 100 is complete, the control device 500 proceeds to step S208, and if not, the control device 500 returns to step S204.

Step S208 is the same as the processing in step S106 in FIG. 5.

As a result, the control device 500 can transition the fuel cell system 100 to a state in which all of the auxiliary devices 120, including the cooling auxiliary devices 120, are operating when the start-up of the fuel cell system 100 is completed, as well as when the cell temperature T is equal to or higher than the threshold value Tth1. Therefore, the control device 500 can prevent the cell temperature T from rising further and causing the fuel cell 112 to overheat.

When processing of step S208 is completed, the control device 500 ends the processing of this flowchart.

[Third Example of Control Method for Self-Startup of Fuel Cell System]
Next, a third example of a control method for independent startup of the fuel cell system 100 will be described with reference to FIGS. 8 to 10 in addition to FIGS. 1 to 4. FIG.

The following description will focus on the differences from the first and second control methods described above, and may omit descriptions of content that is the same as or corresponds to the first and second control methods described above.

<Overview of control method>
Fig. 8 is a time chart illustrating a third example of a control method for the independent startup of the fuel cell system 100. Specifically, Fig. 8 is a time chart showing the change over time in temperature (cell temperature) T of the fuel cell 112 during independent startup of the fuel cell system 100.

As shown in FIG. 8, in this example, at time t21, the control device 500 starts the startup of the fuel cell system 100 when the independent startup conditions are met. At this time, as in the first and second examples described above, only the minimum number of accessories 120 out of all accessories 120 are started. In this example, the minimum number of accessories 120 does not include all of the cooling accessories 120, and the control device 500 does not start any of the cooling accessories 120 when the independent startup of the fuel cell system 100 begins.

After time t21, the cell temperature T increases over time, and at time t22, it transitions to a state that is relatively high relative to the predetermined threshold value Tth11. The threshold value Tth11 may be the same as the threshold value Tth1 in the first example described above, or it may be different.

Here, in this example, the control device 500 starts up some of the cooling accessories 120 out of all the cooling accessories 120 that are not in operation. In this case, the cooling accessories 120 to be started up include, for example, the pump 165. As a result, after time t22, the cell temperature T transitions from an increasing state to a state in which it gradually decreases. Therefore, the control device 500 can prevent a situation in which the fuel cell module 110 becomes overheated due to an increase in the cell temperature T.

After that, at time t23, the start-up of the fuel cell system 100 is completed. Then, in response to the completion of the start-up of the fuel cell system 100, the control device 500 starts up the remaining auxiliary devices 120, including the cooling auxiliary devices 120 that are in a non-operating state, and transitions the fuel cell system 100 to a state in which all auxiliary devices 120 are operating.

In addition, if the cell temperature T continues to rise after time t22 and reaches a state relatively higher than a predetermined threshold value Tth12 (>Tth11) before the start-up of the fuel cell system 100 is completed, the control device 500 may start the remaining cooling accessories 120. In other words, the control device 500 may transition to a state in which all cooling accessories 120 are operated. This makes it possible to suppress the rise in cell temperature T even if the cooling performance achieved by the operation of some of the cooling accessories 120 is not sufficient to suppress the rise in cell temperature T.

In this way, in this example, the control device 500 does not start any of the cooling accessories 120 when the fuel cell system 100 is started. Under this premise, the control device 500 can transition to a state in which some of the cooling accessories 120 are in operation when the cell temperature T becomes relatively high relative to the threshold value Tth11 between the start and completion of the independent startup of the fuel cell system 100. Therefore, the control device 500 can achieve both the reduction of the amount of power used during the independent startup of the fuel cell system 100 and the prevention of an overheating state of the fuel cell module 110 by giving higher priority to the reduction of the amount of power.

<Control flow>
9 is a flow chart showing a third example (part 1) of a control method for the independent startup of a fuel cell system. FIG. 10 is a flow chart showing a third example (part 2) of a control method for the independent startup of a fuel cell system.

As shown in FIG. 9, in step S302, the control device 500 controls the power conversion device 300 to discharge the power storage device 200 to the power distribution system 40, and uses the power to start the minimum number of auxiliary devices 120 and initiate independent startup of the fuel cell system 100. In this example, as described above, the minimum number of auxiliary devices 120 does not include any cooling auxiliary devices 120, and in step S302, the cooling auxiliary devices 120 are not started at all.

When processing of step S302 is completed, the control device 500 proceeds to step S304.

In step S304, the control device 500 determines whether the cell temperature T of at least one of the fuel cell cells 112 of the fuel cell module 110 is equal to or greater than the threshold value Tth11. If the cell temperature T of at least one of the fuel cell cells 112 of the fuel cell module 110 is equal to or greater than the threshold value Tth11, the control device 500 proceeds to step S310; otherwise, the control device 500 proceeds to step S306.

In step S306, the control device 500 performs the same determination as in step S104 of FIG. 5. If the start-up of the fuel cell system 100 is complete, the control device 500 proceeds to step S308, and if not, the control device 500 returns to step S304.

Step S308 is the same as the processing in step S106 in FIG. 5.

When processing of step S308 is completed, the control device 500 ends the processing of this flowchart.

Meanwhile, in step S310, the control device 500 starts up some of the cooling accessories 120.

This allows the control device 500 to prevent the cell temperature T from rising further and causing the fuel cell 112 to overheat.

When processing of step S310 is completed, the control device 500 proceeds to step S312.

In step S312, the control device 500 performs the same determination as in step S104 in FIG. 5. If the start-up of the fuel cell system 100 is complete, the control device 500 proceeds to step S308, and if not, the control device 500 repeats the processing of this step until it is complete.

Also, as shown in FIG. 10, the process of step S311 may be added. In this case, when the process of step S310 is completed, the control device 500 proceeds to step S311.

In step S311, the control device 500 determines whether the cell temperature T of at least one of the fuel cell cells 112 of the fuel cell module 110 is equal to or greater than the threshold value Tth12. If the cell temperature T of at least one of the fuel cell cells 112 of the fuel cell module 110 is equal to or greater than the threshold value Tth12, the control device 500 proceeds to step S308; otherwise, the control device 500 proceeds to step S312.

As shown in FIG. 10, in step S312, if the start-up of the fuel cell system 100 is complete, the control device 500 proceeds to step S308, and if not, returns to step S311.

As a result, when the rise in cell temperature T cannot be suppressed even by operating some of the cooling accessories 120, the control device 500 can suppress the rise in cell temperature T by operating all of the cooling accessories 120.

[Fourth Example of Control Method for Self-Startup of Fuel Cell System]
Next, a fourth 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. 1 to 4.

The following description will focus on the differences from the first to third examples of the control method described above, and may omit descriptions of content that is the same as or corresponds to the first to third examples of the control method described above.

<Overview of control method>
Fig. 11 is a time chart illustrating a fourth example of a control method for the independent startup of the fuel cell system 100. Specifically, Fig. 11 is a time chart showing the change over time in temperature (cell temperature) T of the fuel cell 112 during independent startup of the fuel cell system 100.

As shown in FIG. 11, at time t31, a start-up command for the fuel cell system 100 is input and the independent start-up condition is met. However, because the cell temperature T of the fuel cell 112 is relatively high with respect to a predetermined threshold value Tth2, the control device 500 prohibits the start-up of the fuel cell system 100 and does not initiate start-up of the fuel cell system 100. The threshold value Tth2 is predefined as a value sufficiently smaller than the upper limit value Tlim of the cell temperature T. The upper limit value Tlim corresponds to the boundary between the normal state and the overheated state of the cell temperature T of the fuel cell 112.

After that, the cell temperature T of the fuel cell 112 gradually decreases over time, and at time t32, the cell temperature T reaches a state that is relatively low with respect to the threshold value Tth2. At this point, the control device 500 starts the startup of the fuel cell system 100. At this time, as in the first and second examples described above, the control device 500 starts only the minimum number of accessories 120 out of all the accessories 120, and does not start some or all of the cooling accessories 120 that are not included in the minimum number of accessories 120.

After time t32, the cell temperature T increases over time. However, since the cell temperature T has dropped to a state relatively low with respect to the threshold value Tth2 at the time when the fuel cell system 100 starts to start up, the cell temperature T does not rise to near the upper limit value Tlim, and the start-up of the fuel cell system 100 is completed at time t33. Then, in response to the completion of the start-up of the fuel cell system 100, the control device 500 starts up the remaining accessories 120, including the cooling accessories 120 that are not in operation, and transitions to a state in which all accessories 120 are in operation.

In this way, the control device 500 can start the startup of the fuel cell system 100 from a state in which the cell temperature T is relatively low compared to the threshold value Tth2, on the premise that at least some of the cooling accessories 120 are not operated. Therefore, the control device 500 can prevent a situation in which the cell temperature T rises to the upper limit value Tlim between the startup and completion of the fuel cell system 100. Therefore, the control device 500 can more appropriately prevent a situation in which the fuel cell module 110 overheats, while suppressing the amount of power used during the independent startup of the fuel cell system 100.

<Control flow>
FIG. 12 is a flow chart that illustrates a fourth example of a control method for the independent startup of the fuel cell system 100. In FIG.

As shown in FIG. 12, in step S402, the control device 500 determines whether the cell temperatures T of all fuel cells 112 in the fuel cell module 110 are equal to or lower than the threshold value Tth2. If the cell temperatures T of all fuel cells 112 in the fuel cell module 110 are equal to or lower than the threshold value Tth2, the control device 500 proceeds to step S404; otherwise, the control device 500 ends this flow chart.

As a result, even if the independent startup conditions are met, the control device 500 can prohibit startup of the fuel cell system 100 unless the cell temperatures T of all fuel cell cells 112 have dropped below the threshold value Tth2.

Steps S404, S406, and S408 are the same as steps S102, S104, and S106 in FIG. 5, so their explanation is omitted.

[Fifth Example of Control Method for Self-Startup of Fuel Cell System]
Next, a fifth example of a control method for independent startup of the fuel cell system 100 will be described with reference to FIGS. 13 and 14 in addition to FIGS. 1 to 4.

The control method according to this example is executed when the fuel cell system 100 is stopped, based on any one of the control methods described above in the first to fourth examples.

The following description will focus on the differences from the first to fourth control methods described above, and may omit descriptions of content that is the same as or corresponds to the first to fourth control methods described above.

<Overview of control method>
Fig. 13 is a time chart illustrating a fifth example of a control method for the independent startup of the fuel cell system 100. Specifically, Fig. 13 is a time chart showing the change over time in temperature (cell temperature) T of the fuel cell 112 when the fuel cell system 100 is stopped.

As shown in FIG. 13, at time t41, the control device 500 determines that the stop condition for the fuel cell system 100 is met and starts the stop process for the fuel cell system 100.

The stop condition of the fuel cell system 100 is, for example, that a stop command for the fuel cell system 100 is input while the fuel cell system 100 is operating. The stop 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 stop 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 stop command for the fuel cell system 100 may also be automatically generated according to a predetermined rule. For example, the stop command for the fuel cell system 100 is pseudo-input to the control device 500 by being generated inside the control device 500 at a preset time. The stop command for the fuel cell system 100 may also be generated by an external device at a preset time and input to the control device 500 by communication from the external device.

After time t41, the control device 500 continues processing to shut down the fuel cell system 100 while continuing to operate all cooling accessories 120. As a result, the cell temperature T decreases over time. Then, at time t42, the cell temperature T decreases to a state relatively low with respect to a predetermined threshold value Tth3. The threshold value Tth3 is predefined as a value sufficiently smaller than the upper limit value Tlim of the cell temperature T, similar to the threshold value Tth2 in the fourth example described above. The threshold value Tth3 may be the same as the threshold value Tth2, or may be different.

Here, since the cell temperature T is relatively low compared to the threshold value Tth3, the control device 500 stops the operation of the cooling auxiliary device 120, thereby completing the shutdown process of the fuel cell system 100. As a result, the fuel cell system 100 is shut down at time t42.

In this way, in this example, when the fuel cell system 100 is stopped, the control device 500 can continue to operate the cooling accessories 120 and reduce the cell temperature T to a state relatively low relative to the threshold value Tth3. Therefore, even if the next startup of the fuel cell system 100 is an independent startup, the control device 500 can prevent the cell temperature T from rising to the upper limit value Tlim between the startup and completion of the fuel cell system 100. Therefore, the control device 500 can more appropriately prevent the fuel cell module 110 from overheating while suppressing the amount of power used when starting up the fuel cell system 100.

<Control flow>
FIG. 14 is a flow chart that illustrates a fifth example of a control method for the independent startup of the fuel cell system 100. In FIG.

This flowchart is executed, for example, when the stop condition of the fuel cell system 100 is met.

As shown in FIG. 14, in step S502, the control device 500 starts a process to stop the fuel cell system 100 while continuing to operate all cooling accessories 120. Specifically, the control device 500 starts a process to stop the fuel cell module 110 and a process to stop the accessories 120 other than the cooling accessories 120.

When processing of step S502 is completed, the control device 500 proceeds to step S504.

In step S504, the control device 500 determines whether the cell temperatures T of all fuel cells 112 in the fuel cell module 110 are equal to or lower than the threshold value Tth3. If the cell temperatures T of all fuel cells 112 in the fuel cell module 110 are equal to or lower than the threshold value Tth3, the control device 500 proceeds to step S506. On the other hand, in other cases, the control device 500 repeats the processing of this step until the cell temperatures T of all fuel cells 112 in the fuel cell module 110 are equal to or lower than the threshold value Tth3.

In step S506, the control device 500 starts the process of stopping the cooling accessory 120.

This allows the control device 500 to wait until the cell temperature T of all fuel cell cells 112 in the fuel cell module 110 drops below the threshold value Tth3 before starting the process of stopping the cooling accessories 120.

When processing of step S506 is completed, the control device 500 proceeds to step S508.

In step S508, the control device 500 determines whether the stop process of the fuel cell system 100 has been completed. If the stop process of the fuel cell system 100 has not been completed, the control device 500 repeats the process of this step until it is completed, and if it is completed, ends this flow chart.

[Sixth Example of Control Method for Self-Startup of Fuel Cell System]
Next, a sixth example of a control method for independent startup of the fuel cell system 100 will be described with reference to FIG. 15 in addition to FIGS.

The control method according to this example is performed when two or more fuel cell systems 100 are started independently from a state in which all fuel cell systems 100 are stopped, assuming the power supply system 30 of FIG. 2 described above.

The following explanation will focus on the differences from the first to fifth examples of the control method described above, and explanations of content that is the same as or corresponds to the first to fifth examples of the control method described above may be omitted.

<Overview of control method>
In this example, when the independent start conditions for two or more fuel cell systems 100 are satisfied, the control device 500 performs independent start-up of the first fuel cell system 100 by using any one of the control methods of the first to fourth examples described above. Then, when the independent start-up of the first fuel cell system 100 is completed, the control device 500 performs independent start-up of the second and subsequent fuel cell systems 100 by starting up all the auxiliary devices 120 using the power of the fuel cell system 100 that has already been started. Specifically, the control device 500 controls the fuel cell system 100 that has already been started and the power conversion device 300, and supplies the power of the fuel cell system 100 that has already been started from the power conversion device 300 to the power distribution system 40 through the transformer 400. As a result, the control device 500 can start up the fuel cell system 100 by supplying the power of the fuel cell system 100 that has already been started to the auxiliary devices 120 of the non-operating fuel cell system 100 through the power distribution system 40 and starting up all the auxiliary devices 120. For example, the control device 500 starts up the second and subsequent fuel cell systems 100 one by one in sequence in an independent manner. Also, if the already started fuel cell system 100 has an output margin, the control device 500 may start up the second and subsequent fuel cell systems 100 in an independent manner at the same time.

The first fuel cell system 100 to be started up independently is automatically determined, for example, by predefining the priority order among the multiple fuel cell systems 100. The first fuel cell system 100 to be started up independently may be the fuel cell system 100 with the lowest cell temperature T of the fuel cell 112 among the two or more fuel cell systems 100 to be started up independently. This makes it possible to prevent the fuel cell module 110 from overheating when the first fuel cell system 100 is started up independently with at least a portion of the cooling accessories 120 not in operation.

In this way, in this example, when two or more fuel cell systems 100 are started independently, the control device 500 starts only the first fuel cell system 100 independently using the power of the power storage device 200, and then starts the remaining fuel cell systems 100 using the power of the fuel cell systems 100 that have already been started. As a result, when starting two or more fuel cell systems 100 from a state in which all fuel cell systems 100 are stopped, the control device 500 only needs to supply power from the power storage device 200 to start the first one. As a result, the control device 500 can reduce the amount of power that needs to be discharged from the power storage device 200 when starting two or more fuel cell systems 100 from a state in which all fuel cell systems 100 are stopped. Therefore, the control device 500 can reduce the capacity of the power storage device 200 required to start multiple fuel cell systems 100 independently, and suppress cost increases.

When starting up three or more fuel cell systems 100 independently, the control device 500 may use the power of all of the two or more fuel cell systems 100 that have already been started when starting up the third or subsequent fuel cell systems 100 independently, or may use the power of only some of the fuel cell systems 100.

<Control flow>
FIG. 15 is a flow chart that illustrates a sixth example of a control method for the independent startup of the fuel cell system 100. In FIG.

As shown in FIG. 15, in step S602, the control device 500 controls the power conversion device 300 to discharge the power storage device 200 to the power distribution system 40, and uses the power to start up the minimum number of auxiliary devices 120, thereby starting the independent start-up of the first fuel cell system 100.

When processing of step S602 is completed, the control device 500 proceeds to step S604.

In step S604, the control device 500 determines whether or not the start-up of the first fuel cell system 100 is complete. If the start-up of the first fuel cell system 100 is complete, the control device 500 proceeds to step S606, and if the start-up of the first fuel cell system 100 is not complete, the control device 500 repeats the processing of this step until it is complete.

In step S606, the control device 500 controls the first fuel cell system 100 and the power conversion device 300 to supply power from the first fuel cell system 100 to the auxiliary equipment 120 through the power distribution system 40, thereby starting up the remaining auxiliary equipment 120.

When processing of step S606 is completed, the control device 500 proceeds to step S608.

In step S608, the control device 500 determines whether or not startup of all fuel cell systems 100 to be started has been completed. If startup of all fuel cell systems 100 to be started has not been completed, the control device 500 proceeds to step S610, and if startup has been completed, the control device 500 ends the processing of this flowchart.

In step S610, the control device 500 controls the fuel cell system 100 and power conversion device 300 that are in operation, and supplies power from the fuel cell module 110 through the power distribution system 40 to the auxiliary equipment 120 to operate all of the auxiliary equipment 120, thereby starting the startup of the next fuel cell system 100 to be started.

When the control device 500 completes processing of step S610, it proceeds to step S612.

In step S612, the control device 500 determines whether the startup of the fuel cell system 100 to be started this time has been completed. If the startup of the fuel cell system 100 to be started this time has not been completed, the control device 500 repeats the processing of this step until it is completed, and if it is completed, returns to step S608.

If there is only one fuel cell system 100 to be started, the first processing of step S608 determines that start-up of all fuel cell systems 100 to be started is complete, and the processing of the flowchart ends. On the other hand, if there are N fuel cell systems 100 to be started (N: an integer of 2 or more), the Nth processing of step S608 determines that start-up of all fuel cell systems 100 to be started is complete, and the processing of the flowchart ends.

[Seventh Example of Control Method for Self-Startup of Fuel Cell System]
Next, a seventh example of a control method for independent startup of the fuel cell system 100 will be described with reference to FIG. 16 in addition to FIGS.

The control method according to this example is based on the power supply system 30 of FIG. 3 described above, and is executed when the fuel cell system 100 is started independently for each of two or more power supply systems 30 from a state in which all fuel cell systems 100 are stopped.

The following explanation will focus on the differences from the first to sixth examples above, and explanations of content that is the same as or corresponds to the first to sixth examples above may be omitted.

<Overview of control method>
In this example, when the independent startup condition is met for each of the two or more power supply systems 30 with all fuel cell systems 100 stopped, one of the two or more power supply systems 30 is set as the master, and the rest are set as slaves. For example, bidirectional communication is performed between the control devices 500 of the multiple power supply systems 30, and the control device 500 can grasp the status of the independent startup condition being met in the other power supply systems 30. Then, a priority order is defined in advance among the multiple power supply systems 30, and the power supply system 30 with the highest priority among the two or more target power supply systems 30 is automatically determined to be the master.

The control device 500 included in the master performs independent startup of the fuel cell system 100 included in the master by any one of the control methods of the first to fourth examples and the sixth example described above. Then, when the startup of all the fuel cell systems 100 included in the master is completed, the control device 500 included in the master cooperates with the slave control device 500 and starts the fuel cell system 100 included in the slave using the power of the started fuel cell system 100 included in the master. Specifically, the master control device 500 controls the started fuel cell system 100 and the power conversion device 300, and supplies the power of the started fuel cell system 100 from the power conversion device 300 to the power distribution system 40 through the transformer 400. Then, the slave control device 500 operates all the auxiliary machines 120 of the fuel cell system 100 included in the slave in accordance with the power supply from the master power supply system 30 to the power distribution system 40, thereby starting up the first fuel cell system 100 included in the slave. This allows the slave control device 500 to start up the slave fuel cell system 100 using external power supply from the master fuel cell system 100 without using power from the slave power storage device 200.

When a slave includes multiple fuel cell systems 100 that are to be started independently, after starting up the first fuel cell system 100, the slave control device 500 starts up the remaining fuel cell systems 100 using the power of the already started fuel cell system 100.

In addition, when there are multiple slaves, for example, the master control device 500 cooperates with the target slave control device 500 for each of the multiple slaves to supply power from the master fuel cell system 100 to the target slave and start up the target slave fuel cell system 100. In addition, when there are multiple slaves, the master control device 500 may supply power from the master fuel cell system 100 to two or more slaves and start up the fuel cell systems 100 of the two or more slaves simultaneously.

In this way, in this example, the master control device 500 can cooperate with the slave control device 500 to start up the slave fuel cell system 100 using the power of the master fuel cell system 100 that has already been started up independently. This eliminates the need to start up the slave fuel cell system 100 independently, and eliminates the need to draw power from the slave power storage device 200, allowing the capacity of the slave power storage device 200 to be reduced, thereby reducing costs.

<Control flow>
FIG. 16 is a flow chart that illustrates a seventh example of a control method for the independent startup of the fuel cell system 100. In FIG.

In this example, it is assumed that the master power supply system 30 includes only one fuel cell system 100 (see FIG. 1).

This flowchart is executed by the master control device 500, for example, when the independent startup conditions are met for each of two or more power supply systems 30 among the multiple power supply systems 30 included in the power system 1 with all fuel cell systems 100 stopped.

As shown in FIG. 16, in step S702, the master control device 500 controls the power conversion device 300 to discharge the power from the master power storage device 200 to the power distribution system 40, and uses the power to start up the minimum number of auxiliary devices 120, thereby starting the independent start-up of the master fuel cell system 100.

When processing of step S702 is completed, the master control device 500 proceeds to step S704.

In step S704, the master control device 500 determines whether or not the start-up of the master fuel cell system 100 is complete. If the start-up of the master fuel cell system 100 is complete, the master control device 500 proceeds to step S706, and if not, repeats the processing of this step until it is complete.

In step S706, the master control device 500 controls the fuel cell system 100 and the power conversion device 300 to start up the remaining auxiliary devices 120 by supplying power from the fuel cell module 110 through the power distribution system 40 to the auxiliary devices 120.

When processing of step S706 is completed, the master control device 500 proceeds to step S708.

When the master power supply system 30 includes multiple fuel cell systems 100 (see FIG. 2), for example, steps S608, S610, and S612 in FIG. 15 are added between steps S706 and S708.

In step S708, the master control device 500 sends a notification to the target slave that power supply has begun.

When processing of step S708 is completed, the master control device 500 proceeds to step S710.

In step S710, the master control device 500 controls the master fuel cell system 100 and the power conversion device 300, and supplies power from the master fuel cell system 100 to the target slave through the power distribution system 40.

When processing of step S710 is completed, the master control device 500 proceeds to step S712.

In step S712, the master control device 500 communicates with the target slave control device 500 to determine whether or not startup of the first fuel cell system 100 of the target slave has been completed. If startup of the first fuel cell system 100 of the target slave has been completed, the master control device 500 proceeds to step S714, and if startup of the first fuel cell system 100 of the target slave has not been completed, the master control device 500 returns to step S710 and continues supplying power from the master fuel cell system 100 to the target slave.

In step S714, the master control device 500 determines whether startup of all slave fuel cell systems is complete. If startup of all slave fuel cell systems is not complete, the master control device 500 switches the target slave and returns to step S708; if startup is complete, the process of this flowchart ends.

[Configuration of Fourth Example of Power System]
The configuration of a fourth example of the power system 1 according to this embodiment will be described with reference to FIG.

In the following, configurations that are the same as or correspond to the first to third examples of the configuration of the power system 1 described above will be given the same reference numerals, and the explanation will focus on the parts that are different from the first to third examples described above, and explanations of the same or corresponding content as the first to third examples described above may be omitted.

Figure 17 is a diagram showing the configuration of a fourth example of power system 1.

As shown in FIG. 17, the power system 1 includes a load device 20 and a power supply system 30. In other words, unlike the first example (FIG. 1) to the third example (FIG. 3) described above, the power system 1 of this example does not include an AC power grid 10, and the power supply system 30 cannot receive external power supply.

The power system 1 is mounted, for example, on a work machine that performs a specified task. The work machine is, for example, a mobile transfer crane. The work machine may also be, for example, a stationary transfer crane or a gantry crane. The work machine may also be a work machine for loading and unloading other than a crane, or may be a work machine for other purposes than loading and unloading. The following explanation will be centered on the case where the claim is a work machine.

The load device 20 is electrically connected to the power supply system 30 and is driven by AC supplied from the power supply system 30. The load device 20 is, for example, an actuator that drives a moving part of a work machine. The actuator is, for example, an electric motor for raising and lowering a load suspended by a crane or an electric motor for moving a trolley. The actuator may also be, for example, an electric motor that drives wheels for movement in a mobile work machine.

The power supply system 30 supplies driving power to the load device 20. The power supply system 30 includes a fuel cell system 100, a power storage device 200, a control device 500, an inverter device 600, an inverter device 700, and a converter device 800.

In this example, the power supply system 30 includes one fuel cell system 100, but as in the second example described above, there may be multiple fuel cell systems 100.

The inverter device 600 is electrically connected to the fuel cell system 100 and the power storage device 200 through the DC link unit 250. The inverter device 600 converts the DC of the DC link unit 250 into three-phase AC of a predetermined voltage and frequency and outputs it to the load device 20, thereby enabling the load device 20 to be driven by the power of at least one of the fuel cell system 100 and the power storage device 200.

The inverter device 700 is electrically connected to the fuel cell system 100 and the power storage device 200 through the DC link unit 250. The inverter device 700 converts the DC of the DC link unit 250 into three-phase AC of a predetermined voltage and frequency and outputs it to the auxiliary device 120, thereby enabling the auxiliary device 120 to be driven by the power of at least one of the fuel cell system 100 and the power storage device 200.

The converter device 800 is electrically connected to the fuel cell system 100 and the power storage device 200 through the DC link unit 250. The converter device 800 converts the DC of the DC link unit 250 into DC of a predetermined voltage and outputs it to the control device 500, so that the control device 500 can be driven by the power of at least one of the fuel cell system 100 and the power storage device 200.

The control device 500, for example, controls the inverter device 600 to supply driving power to the load device 20 from at least one of the fuel cell system 100 and the power storage device 200.

The control device 500 may also control the inverter device 700 to supply driving power to the auxiliary device 120 from at least one of the fuel cell system 100 and the power storage device 200.

The control device 500 may also control the converter device 800 to supply driving power to the control device 500 from at least one of the fuel cell system 100 and the power storage device 200.

[Control method for start-up of fuel cell system]
Next, a control method relating to the start-up of the fuel cell system 100 (fourth example) will be described with reference to FIGS. 5 to 15 in addition to FIG.

In this example (FIG. 17), as described above, the power supply system 30 cannot receive external power supply. Therefore, when starting the fuel cell system 100 from a stopped state, the control device 500 controls the inverter device 700 to discharge power from the power storage device 200 through the inverter device 700 to the auxiliary device 120, thereby operating the auxiliary device 120 and starting the fuel cell module 110. Therefore, when starting the fuel cell system 100, the control device 500 can apply a control method similar to the first to sixth examples of the control method for the independent start-up of the fuel cell system 100 described above.

As a result, as with the power supply systems 30 of the first to third examples described above, the amount of power used when starting up the fuel cell system 100 can be reduced. This reduces the capacity of the power storage device 200 required to start up the fuel cell system 100, and reduces the cost of the power storage device 200.

[Other embodiments]
Next, another embodiment will be described.

The above-described embodiments may be modified or altered as appropriate.

For example, in the third example of the control method described above, three or more threshold values for the cell temperature T may be set, so that the proportion of cooling auxiliary devices 120 that are operated among all cooling auxiliary devices 120 may be switched in four or more stages.

In addition, in the third example of the above-mentioned control method and examples of its variations and modifications, the proportion of cooling accessories 120 operated among all cooling accessories 120 may be switched in multiple stages, assuming that the minimum number of accessories 120 includes some of all cooling accessories 120.

In addition, in the second and third examples of the control method described above, the operating status of the cooling auxiliary device 120 may be switched using a threshold value for the amount of increase in cell temperature T from the start of startup of the fuel cell system 100, rather than a threshold value for the cell temperature T of the fuel cell 112.

The second or third example of the control method described above or examples of modifications or variations thereof may be combined with the fourth example of the control method described above.

In the above-described embodiment, a dedicated auxiliary power storage device capable of supplying power to the control device 500 may be provided in addition to the power storage device 200. In the first example (FIG. 1) to the third example (FIG. 3) of the power system 1, the auxiliary power storage device is arranged, for example, in the power path connecting the power distribution system 40 and the control device 500. In the fourth example of the power system 1, the auxiliary power storage device is arranged, for example, in the power path between the converter device 800 and the control device 500. This makes it possible to prevent a situation in which the control device 500 is operated using the power of the power storage device 200 when external power supply is stopped. Therefore, it is no longer necessary to consider the drive power of the control device 500 when determining the capacity of the power storage device 200, and as a result, the capacity of the power storage device 200 can be further reduced.

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

In a first aspect of this embodiment, the power supply system includes a fuel cell, a first power storage device electrically connected to the fuel cell, a plurality of fuel cell accessories that operate electrically, and a control device that controls the startup of the fuel cell. 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 first power storage device is, for example, the power storage device 200 described above. The accessories are, for example, the accessories 120 described above. The control device is, for example, the control device 500 described above. Specifically, the control device starts up the fuel cell by operating only some of the accessories using the power of the first power storage device.

The first aspect of this embodiment is a control method in which a control device controls the start-up of a fuel cell in a power supply system including a fuel cell, a first power storage device electrically connected to the fuel cell, and a number of fuel cell accessories that operate electrically. In the control method, the control device starts up the fuel cell by operating only some of the multiple accessories using the power of the first power storage device.

This allows the control device to reduce the amount of power used to start the fuel cell when starting the fuel cell using the power of the first power storage device. Therefore, the control device can reduce the capacity of the first power storage device required to start the fuel cell using the power of the first power storage device.

In addition, in a second aspect of this embodiment, on the premise of the first aspect described above, the above-mentioned part of the auxiliary equipment may include a fuel supply valve, an intake valve, a compressor, a hydrogen pump, an exhaust valve, and a coolant pump. The fuel supply valve is, for example, the on-off valve 132 described above. The intake valve is, for example, the on-off valve 146 described above. The compressor is, for example, the compressor 144 described above. The hydrogen pump is, for example, the pump 133 described above. The exhaust valve is, for example, the on-off valve 152 described above. The coolant pump is, for example, the pump 165 described above. Specifically, the fuel supply valve is provided in a fuel supply path to the fuel cell. The supply path is, for example, the supply path L1 described above. The intake valve is provided in an air supply path to the fuel cell. The air supply path is, for example, the air supply path L3 described above. The compressor pressurizes air to the fuel cell through the air supply path. The hydrogen pump is used to circulate excess hydrogen from the fuel cell. The exhaust valve is provided in the exhaust path for exhaust and drainage from the fuel cell. The exhaust path is, for example, the above-mentioned exhaust path L4. The coolant pump is used to circulate the coolant that exchanges heat with the fuel cell.

As a result, the control device can start up the fuel cell by operating the fuel supply valve, air intake valve, compressor, hydrogen pump, and exhaust valve. The control device can also ensure a certain degree of cooling performance when the fuel cell is started up by operating the coolant pump.

In addition, in a third aspect of this embodiment, assuming the first or second aspect described above, the multiple auxiliaries may include multiple cooling auxiliaries for cooling the fuel cell. And, some of the auxiliaries may not include some or all of the multiple cooling auxiliaries.

As a result, the control device can predict that the temperature of the fuel cell will be relatively low when the fuel cell is stopped and limit the operation of the cooling accessories, thereby reducing the capacity of the first power storage device required to start the fuel cell using the power of the first power storage device.

In addition, in a fourth aspect of this embodiment, assuming the third aspect described above, the control device may operate a cooling auxiliary device that is not included in some of the multiple cooling auxiliary devices when the temperature of the fuel cell becomes relatively high with respect to a first criterion between the start and completion of the startup of the fuel cell, or when the amount of increase in the temperature of the fuel cell becomes relatively large with respect to a second criterion. The first criterion is, for example, the threshold value Tth1 or threshold value Tth11 described above.

As a result, when the fuel cell is started up using the power of the first power storage device and the temperature of the fuel cell is relatively high, the control device can operate additional cooling accessories to prevent the fuel cell from overheating. Therefore, the control device can more appropriately prevent the fuel cell from overheating while limiting the amount of power used when starting up the fuel cell using the power of the first power storage device.

In addition, in a fifth aspect of this embodiment, based on the fourth aspect described above, two or more of the multiple cooling auxiliaries may not be included in the partial auxiliaries. Then, when the temperature of the fuel cell becomes relatively high with respect to the first standard between the start and completion of the startup of the fuel cell, or when the amount of increase in the temperature of the fuel cell becomes relatively high with respect to the second standard, the control device may operate only some of the two or more cooling auxiliaries.

This allows the control device to more appropriately achieve both reduction in the amount of power used to start up the fuel cell using power from the first power storage device and prevention of the fuel cell overheating.

In addition, in a sixth aspect of this embodiment, assuming any one of the third to fifth aspects described above, the control device may prohibit the start-up of the fuel cell if the temperature of the fuel cell is relatively high with respect to a third criterion before the start-up of the fuel cell. The third criterion is, for example, the threshold value Tth2 described above.

This allows the control device to prevent the fuel cell from starting if the temperature of the fuel cell is not sufficiently low. Therefore, the control device can prevent a situation in which the fuel cell overheats, for example, when the temperature of the fuel cell is relatively high and the fuel cell starts up without some or all of the cooling accessories being operated.

In addition, in a seventh aspect of this embodiment, assuming any one of the above-mentioned third to sixth aspects, the control device may control a plurality of cooling auxiliaries when the fuel cell is stopped, to make the temperature of the fuel cell relatively low with respect to the fourth criterion. The fourth criterion is, for example, the above-mentioned threshold value Tth3.

As a result, the control device can lower the temperature of the fuel cell to a relatively low state when the fuel cell is stopped. Therefore, the control device can then start the fuel cell using the power of the first power storage device, starting from a state in which the temperature of the fuel cell has sufficiently dropped. Therefore, the control device can more appropriately prevent the fuel cell from overheating while limiting the amount of power used when starting the fuel cell by using the power of the first power storage device.

In addition, in an eighth aspect of this embodiment, assuming any one of the first to seventh aspects described above, there may be a plurality of fuel cells. When starting up a first fuel cell and a second fuel cell included in the plurality of fuel cells, the control device may start up the first fuel cell by operating only some of the plurality of auxiliaries using the power of the first power storage device, and after the start-up of the first fuel cell is completed, start up the second fuel cell by operating the plurality of auxiliaries using the power of the first fuel cell.

As a result, when starting up multiple fuel cells using the first power storage device, the control device can operate one of the fuel cells using the first power storage device and start up the remaining fuel cells using the power of the remaining fuel cells and the fuel cells that have already been started. Therefore, the control device can reduce the capacity of the first power storage device required to start up multiple fuel cells using the first power storage device.

In addition, in a ninth aspect of this embodiment, based on the eighth aspect described above, when the control device starts up the first fuel cell, the second fuel cell, and the third fuel cell included in the multiple fuel cells, the control device may start up the first fuel cell by operating only some of the multiple auxiliaries using the power of the first power storage device, start up the second fuel cell by operating the multiple auxiliaries using the power of the first fuel cell after the start-up of the first fuel cell is completed, and start up the third fuel cell by operating the multiple auxiliaries using the power of at least one of the first fuel cell and the second fuel cell after the start-up of the second fuel cell is completed.

This allows the control device to start up three or more fuel cells one by one. Therefore, in a situation where it is necessary to start up multiple power storage devices using the power of the first power storage device, the control device can distribute the amount of power used to start up the fuel cells in a chronological order, thereby preventing a shortage of power to start up the fuel cells.

In addition, in a tenth aspect of this embodiment, based on the eighth or ninth aspect described above, the multiple auxiliaries include multiple cooling auxiliaries for cooling the fuel cell, and some auxiliaries do not include some or all of the multiple cooling auxiliaries. The first fuel cell may be the fuel cell with the lowest temperature among the two or more fuel cells to be started.

As a result, when starting up the first fuel cell using power from the first power storage device, the control device can prevent the first fuel cell from overheating even in a situation where some or all of the multiple cooling accessories are not operating.

In addition, in an eleventh aspect of this embodiment, assuming any one of the first to tenth aspects described above, the control device may start up the fuel cell by operating only some of the multiple auxiliaries using the power of the first power storage device, and after the start-up of the fuel cell is completed, may cooperate with another power supply system electrically connected to the fuel cell and start up another fuel cell included in the other power supply system using the power of the already started fuel cell.

This allows the control device to reduce the capacity of the power storage devices included in other power supply systems.

In addition, in a twelfth aspect of this embodiment, assuming any one of the first to eleventh aspects described above, the fuel cell may be a polymer electrolyte fuel cell.

As a result, the time required to start up the polymer electrolyte fuel cell is extremely short, so the power supply system can more appropriately prevent situations in which an abnormality occurs in the fuel cell even if the operation of multiple auxiliary devices is limited to only some of the auxiliary devices.

In addition, in a thirteenth aspect of this embodiment, a second storage device that supplies power to the control device may be provided in addition to the first storage device. The second storage device is the auxiliary storage device described above.

This makes it possible to prevent, for example, a situation in which the control device causes the charge state of the first power storage device to decrease while the fuel cell is stopped. This makes it possible to optimize the capacity of the first power storage device and the second power storage device, and to optimize the cost of the first power storage device and the second power storage device.

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 of the invention as described in the claims.

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 device 130 Fuel supply section 131 Hydrogen supply source 132 Opening/closing valve 133 Pump 134 Gas-liquid separator 140 Air supply section 142 Air cleaner 144 Compressor 146 Opening/closing valve 150 Discharge section 152 Opening/closing valve 154 Mixer 156 Gas-liquid separator 160 Cooling section 161 Cooler 162 Fan 163 Pump 164 Heat exchanger 165 Pump 166 Ion exchanger 200 Electric storage device 250 DC link section 300 Power conversion device 400 Transformer 500 Control device 600, 700 Inverter device 800 Converter devices CC1, CC2 Cooling circuit L1 Supply path L2 Circulation path L3 Air supply path L4 Exhaust path

Claims (14)

A fuel cell;
a first power storage device electrically connected to the fuel cell;
a plurality of electrically powered auxiliary components of the fuel cell;
A control device that controls the start-up of the fuel cell;
a second power storage device provided separately from the first power storage device and supplying power to the control device;
the control device starts up the fuel cell by operating only a portion of the plurality of auxiliaries using the electric power of the first power storage device;
Power supply system. The part of the auxiliary equipment includes a fuel supply valve provided in a fuel supply path to the fuel cell, an air supply valve provided in an air supply path to the fuel cell, a compressor that pressurizes air to the fuel cell through the air supply path, a hydrogen pump for circulating surplus hydrogen in the fuel cell, a discharge valve provided in a discharge path for exhaust gas and wastewater from the fuel cell, and a coolant pump for circulating a coolant that exchanges heat with the fuel cell.
The power supply system according to claim 1 . the plurality of auxiliaries include a plurality of cooling auxiliaries for cooling the fuel cell,
The part of the auxiliary machines does not include some or all of the plurality of cooling auxiliary machines.
The power supply system according to claim 1 or 2. the control device operates a cooling auxiliary device that is not included in the part of the auxiliary devices among the plurality of cooling auxiliary devices when the temperature of the fuel cell becomes relatively high with respect to a first standard or when an amount of increase in the temperature of the fuel cell becomes relatively large with respect to a second standard during a period from the start to the completion of startup of the fuel cell;
The power supply system according to claim 3 . Two or more cooling auxiliaries among the plurality of cooling auxiliaries are not included in the portion of the auxiliaries,
the control device operates only a part of the two or more cooling auxiliary machines when the temperature of the fuel cell becomes relatively high with respect to the first reference or when the amount of increase in the temperature of the fuel cell becomes relatively high with respect to the second reference during the period from the start to the completion of the start-up of the fuel cell;
The power supply system according to claim 4 . the control device prohibits the start-up of the fuel cell when the temperature of the fuel cell is relatively high with respect to a third standard before the start-up of the fuel cell;
The power supply system according to claim 3 . the control device controls the plurality of cooling auxiliaries when the fuel cell is stopped, to keep the temperature of the fuel cell relatively low with respect to a fourth reference temperature;
The power supply system according to claim 3 . The fuel cell is a plurality of fuel cells,
When starting up a first fuel cell and a second fuel cell included in the plurality of fuel cells, the control device starts up the first fuel cell by operating only some of the plurality of auxiliaries using the power of the first power storage device, and after the start-up of the first fuel cell is completed, starts up the second fuel cell by operating the plurality of auxiliaries using the power of the first fuel cell.
The power supply system according to claim 1 or 2. When starting up the first fuel cell, the second fuel cell, and the third fuel cell included in the plurality of fuel cells, the control device starts up the first fuel cell by operating only some of the plurality of auxiliaries using the power of the first power storage device, starts up the second fuel cell by operating the plurality of auxiliaries using the power of the first fuel cell after the start-up of the first fuel cell is completed, and starts up the third fuel cell by operating the plurality of auxiliaries using the power of at least one of the first fuel cell and the second fuel cell after the start-up of the second fuel cell is completed.
The power supply system according to claim 8. the plurality of auxiliaries include a plurality of cooling auxiliaries for cooling the fuel cell,
The part of the auxiliary machines does not include some or all of the plurality of cooling auxiliary machines,
the first fuel cell is the fuel cell having the lowest temperature among the two or more fuel cells to be started;
The power supply system according to claim 8. the control device starts up the fuel cell by operating only the part of the plurality of auxiliaries using the power of the first power storage device, and after the start-up of the fuel cell is completed, cooperates with another power supply system electrically connected to the fuel cell, and starts up another fuel cell included in the other power supply system using the power of the fuel cell;
The power supply system according to claim 1 or 2. The fuel cell is a polymer electrolyte fuel cell.
The power supply system according to claim 1 or 2. A control device for controlling start-up of a fuel cell in a power supply system including a fuel cell, a first power storage device electrically connected to the fuel cell, a plurality of electrically operated auxiliary devices of the fuel cell, and a second power storage device provided separately from the first power storage device, comprising:
Electric power is supplied from the second power storage device,
starting up the fuel cell by operating only a portion of the plurality of auxiliary machines using the electric power of the first power storage device;
Control device. A control method for a power supply system including a fuel cell, a first power storage device electrically connected to the fuel cell, a plurality of electrically operated auxiliary devices of the fuel cell, and a second power storage device provided separately from the first power storage device, the method comprising: a control device to which power is supplied from the second power storage device controls start-up of the fuel cell, the control method comprising the steps of:
the control device starts up the fuel cell by operating only a portion of the plurality of auxiliaries using the electric power of the first power storage device;
Control methods.

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