Fuel cell system start circuit, method and controller

Abstract

The application relates to the technical field of fuel cells, and provides a fuel cell system starting circuit, method and controller, the circuit comprising a controller, a boost DC / DC converter, an output bus capacitor, a main pre-charging circuit and an auxiliary pre-charging circuit, wherein: the input end of the boost DC / DC converter is connected with a stack, and the output end of the boost DC / DC converter is connected with a power battery through the output bus capacitor and the main pre-charging circuit; a BOP device is connected with the power battery through the auxiliary pre-charging circuit; the controller is used for independently pre-charging and power supply management of the output bus capacitor of the boost DC / DC converter and the BOP device respectively, and the bus voltage of the output bus capacitor after pre-charging is completed is the power battery voltage. The application can realize effective control of the stack voltage and current in the fuel cell system starting process, saves the power devices required by the boost-buck topology, reduces the equipment cost, equipment volume and weight, and improves the efficiency.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and in particular to a fuel cell system start-up circuit, method, and controller. Background Technology

[0002] Developing high-power fuel cell systems suitable for medium and heavy-duty trucks is an inevitable trend. Currently, the installed power requirement for heavy-duty trucks is in the 240kW range. For example, a typical hydrogen fuel cell heavy-duty truck installation scenario involves a fuel cell system with a single stack of 550 cells, an open-circuit voltage of approximately 560V, an idle voltage of approximately 451V, and a rated voltage of approximately 355V. The power battery system uses a 600V platform with a voltage range of 450V to 750V. Since there is an overlap between the stack's output voltage range and the power battery's voltage range, the fuel cell DC / DC converter (DCF) integrated in the fuel cell system's power control unit (PCU) needs to employ a multi-channel interleaved parallel four-tube buck-boost topology to achieve controllable power conversion across the entire range.

[0003] However, the multi-channel interleaved parallel four-transistor buck-boost topology uses a large number of electronic components such as power switching transistors and diodes, which significantly increases the equipment cost, size and weight, and also has high control complexity and low system efficiency. Summary of the Invention

[0004] This invention provides a starting circuit, method, and controller for a fuel cell system, which addresses the shortcomings of existing technologies that employ a large number of power devices, resulting in high cost, increased size and weight, high control complexity, and low efficiency due to numerous steps.

[0005] This invention provides a fuel cell system start-up circuit, comprising: a controller, a boost DC / DC converter, an output bus capacitor, a main pre-charge circuit, and an auxiliary pre-charge circuit, wherein:

[0006] The input terminal of the boost DC / DC converter is connected to the fuel cell stack, and the output terminal of the boost DC / DC converter is connected to the power battery through the output bus capacitor and the main pre-charge circuit.

[0007] The BOP device, which serves as an auxiliary device for the fuel cell stack, is connected to the power battery via the auxiliary pre-charging circuit.

[0008] The controller is used to independently pre-charge and power supply the output bus capacitor of the boost DC / DC converter and the BOP device, and after the pre-charging is completed, the bus voltage of the output bus capacitor is the power battery voltage; it is also used to control the change between the power battery voltage and the open circuit voltage of the output bus capacitor and the chopping operation of the boost DC / DC converter after the pre-charging is completed and the open circuit voltage of the fuel cell stack is higher than the power battery voltage, thereby completing the start-up of the fuel cell system.

[0009] According to the fuel cell system startup circuit provided by the present invention, the controller controls the change of the bus voltage of the output bus capacitor between the power battery voltage and the open circuit voltage, and the chopping operation of the boost DC / DC converter to complete the startup of the fuel cell system, including:

[0010] The auxiliary pre-charging circuit is kept on to control the BOP device to continue operating;

[0011] By disconnecting the fuel cell stack from the power battery, the fuel cell stack voltage and the bus voltage of the output bus capacitor are controlled to rise to the open circuit voltage.

[0012] After meeting the single-cell consistency condition of the fuel cell stack, the stack voltage and the bus voltage are controlled to decrease from the open-circuit voltage to the power battery voltage.

[0013] By controlling the chopper operation of the boost DC / DC converter, the voltage of the fuel cell stack is reduced from the voltage of the power battery to the rated voltage, thus completing the start-up of the fuel cell.

[0014] According to the fuel cell system start-up circuit provided by the present invention, the main pre-charge circuit includes a main pre-charge branch and a main positive contactor connected in parallel, and the main pre-charge branch includes a main pre-charge resistor and a main pre-charge contactor connected in series.

[0015] According to the fuel cell system start-up circuit provided by the present invention, the auxiliary pre-charge circuit includes an auxiliary pre-charge branch and an auxiliary positive contactor connected in parallel, and the auxiliary pre-charge branch includes an auxiliary pre-charge resistor and an auxiliary pre-charge contactor connected in series.

[0016] According to the fuel cell system startup circuit provided by the present invention, the boost DC / DC converter includes multiple interleaved parallel BOOST boost circuits; each of the BOOST boost circuits is connected to the controller; the controller is used to perform phase-shift control on each of the BOOST boost circuits based on a PWM signal.

[0017] According to the fuel cell system start-up circuit provided by the present invention, the controller is also connected to the vehicle CAN network for communication. The controller is also used to receive the power battery voltage transmitted by the vehicle CAN network and to sample and obtain the bus voltage and stack voltage.

[0018] The present invention also provides a fuel cell system start-up method, applied to a fuel cell system start-up circuit as described in any of the preceding claims, the method comprising:

[0019] The on / off state of the main pre-charging circuit is controlled to independently pre-charge the output bus capacitor, and the on / off state of the auxiliary pre-charging circuit is controlled to independently pre-charge and manage the power supply of the BOP device; after the pre-charging is completed, the bus voltage of the output bus capacitor is the power battery voltage.

[0020] When the pre-charging of the output bus capacitor and the BOP device is completed, and the open-circuit voltage of the stack is higher than the voltage of the power battery, the connection between the stack and the power battery is disconnected, and the stack voltage of the stack, together with the bus voltage, is controlled to rise to the open-circuit voltage.

[0021] After the single-cell consistency condition of the fuel cell stack is met, the main pre-charge contactor in the main pre-charge circuit is closed, and the fuel cell stack voltage and the bus voltage are pulled down to the power battery voltage through the main pre-charge resistor in the main pre-charge circuit.

[0022] Close the main positive contactor in the main pre-charge circuit, open the main pre-charge contactor, and control the chopper operation of the boost DC / DC converter to reduce the stack voltage to the rated voltage, thus completing the start-up of the fuel cell system.

[0023] According to the fuel cell system startup method provided by the present invention, the step of controlling the stack voltage to decrease to the rated voltage by controlling the chopping operation of the boost DC / DC converter includes:

[0024] By controlling the duty cycle of the boost DC / DC converter, the output current of the fuel cell stack is increased to reduce the fuel cell stack voltage until the fuel cell stack voltage is reduced to the rated voltage.

[0025] According to the fuel cell system startup method provided by the present invention, disconnecting the fuel cell stack from the power battery includes:

[0026] Disconnect the main positive contactor and the main precharge branch.

[0027] The present invention also provides a controller, including a processor, an ADC sampling module, a memory, a CAN communication module, a communication interface, a PWM module, and a computer program stored in the memory and executable on the processor. The processor, the ADC sampling module, the memory, the CAN communication module, the PWM module, and the communication interface are all connected via a bus.

[0028] The CAN communication module is connected to the vehicle's CAN network, and the CAN communication module is used to obtain the power battery voltage;

[0029] The ADC sampling module is used to acquire the bus voltage and stack voltage corresponding to the output bus capacitor;

[0030] The PWM module is used to generate control signals, which are used to control the chopping operation of the boost DC / DC converter.

[0031] When the processor executes the computer program, it implements the fuel cell system startup method as described in any of the above.

[0032] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the fuel cell system startup method as described above.

[0033] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the fuel cell system startup method as described above.

[0034] The fuel cell system startup circuit, method, and controller provided by this invention independently control the main pre-charge circuit and the auxiliary pre-charge circuit, and independently manage the pre-charge and power supply of the output bus capacitor and BOP device. After pre-charging is completed and the power battery voltage is lower than the open-circuit voltage of the stack, the startup of the fuel cell system is completed by controlling the change of the bus voltage of the output bus capacitor between the power battery voltage and the open-circuit voltage, and by the chopping operation of the boost DC / DC converter. In this invention, a boost DC / DC converter replaces the buck-boost topology. By controlling the dynamic change of the bus voltage between the power battery voltage and the open-circuit voltage, and by the chopping operation of the boost DC / DC converter, the fuel cell system can be started smoothly. This saves the use of a large number of electronic components required for the buck module in the buck-boost topology, thereby significantly reducing equipment costs, size, and weight, and making control simpler, more reliable, and more efficient. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0036] Figure 1 This is a connection diagram of the fuel cell system start-up circuit provided in an embodiment of the present invention.

[0037] Figure 2 This is a partial schematic diagram of the start-up circuit of the fuel cell system provided in an embodiment of the present invention.

[0038] Figure 3 This is a schematic diagram of the topology of the BOOST boost circuit provided in an embodiment of the present invention.

[0039] Figure 4 This is a circuit diagram of the fuel cell system startup circuit provided in an embodiment of the present invention.

[0040] Figure 5 This is a connection diagram of the fuel cell system provided in an embodiment of the present invention.

[0041] Figure 6 This is one of the flowcharts illustrating the fuel cell start-up method provided in this embodiment of the invention.

[0042] Figure 7 This is the second schematic flowchart of the fuel cell start-up method provided in the embodiments of the present invention.

[0043] Figure 8 This is a schematic diagram of voltage changes during the start-up process of a fuel cell provided in an embodiment of the present invention.

[0044] Figure 9 This is a schematic diagram of the logic topology of the controller provided in an embodiment of the present invention.

[0045] Figure label:

[0046] 110: Boost DC / DC converter; 111: BOOST boost circuit; 120: Main pre-charge circuit; 121: Main pre-charge branch; 130: Auxiliary pre-charge circuit; 131: Auxiliary pre-charge branch; 140: Controller; 150: BOP device; 160: Discharge circuit; 170: Input support capacitor branch; 180: Air compressor controller; 190: BOP PDU; 200: Fuel cell stack; 210: Fuel cell CAN network; 220: Fuel cell control unit; 230: Vehicle CAN network; 300: Power battery. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0048] In a hydrogen fuel cell heavy-duty truck installation scenario, assuming a single stack structure with 550 cells, an open-circuit voltage (Voc) of approximately 560V, an idle voltage of approximately 451V, and a rated voltage of approximately 355V, and a power battery system using a 600V platform with a voltage range of 450V to 750V, the fuel cell stack output voltage range overlaps with the power battery voltage range. Therefore, the fuel cell DC / DC converter (DCF) integrated in the fuel cell system's power control unit (PCU) needs to employ a multi-path interleaved parallel buck-boost topology to achieve controllable power conversion across the entire range.

[0049] However, under normal circumstances, the Vehicle Control Unit (VCU) controls the SOC (State of Charge) range of the power battery. The power battery voltage Vbat can only drop to 450V under extreme conditions such as prolonged storage, low charge, and low temperature; it rarely drops to around 450V under other conditions. After the battery stack starts up, the DCF continuously outputs a large current, keeping the stack output voltage Vc1 at a low level. In other words, the buck module in the buck-boost topology only becomes active when the power battery voltage Vbat drops to around 450V. Under other conditions, the buck module's switching transistors remain on, failing to perform its buck-boost function and resulting in wasted resources.

[0050] The buck-boost topology uses a large number of electronic components such as power switches and diodes, which significantly increases the equipment cost, size and weight, and also increases the control complexity, thereby reducing control efficiency.

[0051] To address the aforementioned problems in the prior art, embodiments of the present invention provide a fuel cell system start-up circuit. Figure 1 This is a connection diagram of the fuel cell system start-up circuit provided in an embodiment of the present invention, as shown below. Figure 1 As shown, the fuel cell system startup circuit includes: a controller 140, a boost DC / DC converter 110, an output bus capacitor, a main pre-charge circuit 120, and an auxiliary pre-charge circuit 130.

[0052] The input terminal of the boost DC / DC converter 110 is connected to the fuel cell stack 200, and the output terminal of the boost DC / DC converter 110 is connected to the power battery 300 through the output bus capacitor and the main pre-charge circuit 120.

[0053] The Balance of Plant (BOP) device, which serves as an auxiliary device for the fuel cell stack 200, is connected to the power battery 300 via the auxiliary pre-charging circuit 130.

[0054] The controller 140 is used to independently pre-charge and power supply the output bus capacitor of the boost DC / DC converter 110 and the BOP device 150, respectively, and after the pre-charging is completed, the bus voltage of the output bus capacitor is the power battery voltage; it is also used to control the change between the power battery voltage and the open circuit voltage of the output bus capacitor, and the chopping operation of the boost DC / DC converter 110, in the case that after the pre-charging is completed and the open circuit voltage of the fuel cell stack 200 is higher than the power battery voltage, to complete the start-up of the fuel cell system.

[0055] It should be noted that the power source of the fuel cell system is the fuel cell stack 200, which is an energy conversion device that converts the chemical energy of fuel and oxidant into electrical energy through an electrochemical reaction. The fuel cell stack 200 consists of multiple single cells connected in series. Fuel and oxidant react within the fuel cell stack 200 to convert chemical energy into electrical energy. The power battery 300 is an energy storage device that stores electrical energy through a chemical reaction and releases it when needed. After generating electrical energy, the fuel cell system connects to the power battery 300 via the output of the boost DC / DC converter 110. The electrical energy can be stored in the power battery 300, and the output voltage of the fuel cell system is the voltage of the power battery.

[0056] The boost DC / DC converter 110 is a key component of the fuel cell system, used to boost the voltage Vc1 of the fuel cell stack 200. It enables energy flow between the fuel cell stack 200 and the power battery 300 over a wide voltage range, effectively charging the power battery 300. The boost DC / DC converter 110 achieves voltage boosting through a BOOST boost circuit 111, a switching power converter capable of converting a lower input voltage to a higher output voltage.

[0057] The BOP (Base Plant) unit 150 includes, but is not limited to, components such as an air compressor, a water pump, a PTC (Positive Temperature Coefficient) heater, a cooling fan, a hydrogen pump, and an ejector. These components support the normal operation of the fuel cell stack 200. The air compressor provides the necessary oxygen to the stack 200. The water pump controls the moisture content inside the stack 200. The PTC heater and cooling fan maintain the temperature of the stack 200. The hydrogen pump and ejector provide the required hydrogen to the stack 200. Furthermore, the fuel cell system startup circuit includes an air compressor controller 180 and a BOP PDU (Power Distribution Unit) 190. The auxiliary pre-charge circuit 130 is connected to the air compressor via the air compressor controller 180. The BOP PDU 190 is connected to the PTC heater, cooling fan, hydrogen pump, and ejector, and is used to distribute power to these components, thereby maintaining a stable operating state.

[0058] In this embodiment of the invention, both the main pre-charging circuit 120 and the auxiliary pre-charging circuit 130 are pre-charging circuits and operate independently. Upon receiving a standby command from the user, the controller 140 can control the main pre-charging circuit 120 to pre-charge the output bus capacitor, and simultaneously control the auxiliary pre-charging circuit 130 to pre-charge the BOP device 150. This ensures that the output bus capacitor and the BOP device 150 reach a safe operating voltage before the fuel cell stack 200 starts up, preventing electrical breakdown caused by the output bus capacitor being directly connected to the fuel cell stack 200 and the power battery 300 without charging, and avoiding damage to sensitive electronic components in the BOP device 150 from instantaneous high current. This reduces safety risks during the fuel cell stack 200 startup process and provides a guarantee for the smooth startup of the fuel cell system.

[0059] When the controller 140 receives the pre-charge end signal corresponding to the output bus capacitor and the BOP device 150, the bus voltage Vc2 of the output bus capacitor and the BOP device 150 can be pre-charged to the power battery voltage Vbat. This can minimize the over-discharge in the early stage of the battery stack 200 startup and reduce the charging and discharging surge current caused by the difference between the power battery voltage and the battery stack voltage. In addition, pre-charging can also shorten the startup time of the battery stack 200.

[0060] Upon receiving the start command from the user, the controller 140 determines whether the power battery voltage Vbat is lower than the open-circuit voltage Voc of the fuel cell stack 200. If the power battery voltage Vbat is higher than or equal to the open-circuit voltage Voc, the voltage Vc1 of the fuel cell stack 200 can be boosted through the boost DC / DC converter 110 to charge the power battery 300 normally. If the power battery voltage Vbat is lower than the open-circuit voltage Voc, the main pre-charge circuit 120 is disconnected, and the fuel cell stack 200 enters the start-up phase. By controlling the dynamic change of the bus voltage of the output bus capacitor between the power battery voltage and the open-circuit voltage, and by controlling the chopping operation of the boost DC / DC converter 110, the fuel cell system is smoothly transitioned to the BOOST operation mode, thus realizing the start-up of the fuel cell system.

[0061] It should be noted that the controller 140 can determine whether the pre-charging process has ended by the output bus capacitor voltage or the pre-charging end communication signal from the air compressor controller 180. For example, if the bus voltage is detected to be equal to the power battery voltage, it indicates that the output bus capacitor pre-charging has ended, and the BOP device 150 and the air compressor controller 180 send a CAN (Controller Area Network) message to indicate that the pre-charging is complete, thus ending the pre-charging process.

[0062] Furthermore, the controller 140 controls the change of the bus voltage of the output bus capacitor between the power battery voltage and the open-circuit voltage, and the chopping operation of the boost DC / DC converter 110, to complete the startup of the fuel cell system, including:

[0063] The auxiliary pre-charging circuit 130 is kept on to control the BOP device 150 to continue operating;

[0064] By disconnecting the fuel cell stack 200 from the power battery 300, the voltage of the fuel cell stack 200 and the bus voltage of the output bus capacitor are controlled to rise to the open circuit voltage.

[0065] After meeting the single-cell consistency condition of the fuel cell stack 200, the voltage of the fuel cell stack 200 and the bus voltage are controlled to decrease from the open circuit voltage to the power battery voltage.

[0066] By controlling the chopping operation of the boost DC / DC converter 110, the voltage of the fuel cell stack 200 is reduced from the power battery voltage to the rated voltage, thus completing the start-up of the fuel cell.

[0067] Specifically, after pre-charging is completed, the auxiliary pre-charging circuit 130 is turned on, allowing the BOP device 150 to continue operating and providing a stable reaction environment for the fuel cell stack 200, such as supplying oxygen and hydrogen, and regulating temperature and moisture content. Afterwards, the connection between the fuel cell stack 200 and the power battery 300 is disconnected. Charge accumulates at the positive and negative electrodes of the fuel cell stack 200, and the voltage Vc1 of the fuel cell stack 200 gradually increases until it reaches the voltage Vbat of the power battery. Charge continues to accumulate at the positive and negative electrodes of the fuel cell stack 200 until the voltage Vc1 reaches the open-circuit voltage of the fuel cell stack 200. A small amount of charge on the positive and negative electrodes of the fuel cell stack 200 is output to the output bus capacitor for charging. Since the main pre-charging circuit 120 is disconnected, the bus voltage Vc2 of the output bus capacitor will rise to near the open-circuit voltage Voc, following the continued rise of the voltage Vc1 of the fuel cell stack 200. At this point, the stack voltage Vc1 rises to the open-circuit voltage Voc and remains briefly near it. After ensuring that the stack 200 meets the single-cell consistency condition, the output bus capacitor is controlled to discharge, causing the bus voltage Vc2 to drop to the power battery voltage Vbat. When the bus voltage Vc2 is detected to be level with the power battery voltage Vbat over a continuous period, the boost DC / DC converter 110 is controlled to operate in chopping mode, increasing the output current of the stack 200. This reduces the stack voltage Vc1 from the open-circuit voltage Voc to the rated voltage, allowing the stack 200 to smoothly transition from the startup state to the BOOST operating mode, thus achieving a successful start-up of the fuel cell system. After the fuel cell system starts, the output voltage Vc1 of the stack 200 can be adjusted by controlling the duty cycle of the BOOST boost circuit 111 in the boost DC / DC converter 110.

[0068] It should be noted that when the absolute value of the difference between the bus voltage Vc2 and the open-circuit voltage Voc is less than a preset threshold, it can be indicated that the bus voltage Vc2 is approximately equal to the open-circuit voltage Voc. The preset threshold is a minimum value used to characterize the degree of approximation between the bus voltage Vc2 and the open-circuit voltage Voc of the fuel cell stack 200. The preset threshold can be set based on experience. For example, the preset threshold can be 0.1V, 0.5V, or 1V, etc. The embodiments of the present invention do not limit this.

[0069] It should be noted that the single-cell consistency condition of the fuel cell stack 200 means that the performance of each individual cell in the fuel cell stack 200 remains consistent. The performance of each individual cell may include: voltage, current, temperature, chemical reaction rate, moisture and reaction gas distribution, etc., which are not limited in this embodiment of the invention.

[0070] Furthermore, Figure 2 This is a partial schematic diagram of the fuel cell system startup circuit provided in an embodiment of the present invention, as shown below. Figure 2As shown, the main pre-charge circuit 120 includes a main pre-charge branch 121 and a main positive contactor K1 connected in parallel, and the main pre-charge branch 121 includes a main pre-charge resistor R4 and a main pre-charge contactor K4 connected in series.

[0071] Specifically, by default, the main negative contactor K2, the main positive contactor K1, and the pre-charge contactor K4 are all in the open state. After the controller 140 receives a standby command from the user, it can control the main negative contactor K2 to close, which in turn controls the pre-charge contactor K4 to close. The current generated by the power battery 300 flows into the output bus capacitor to pre-charge it. After the output bus capacitor is pre-charged, the controller controls the main positive contactor K1 to close and the controller controls the pre-charge contactor K4 to open. At this time, the bus voltage Vc2 corresponding to the output bus capacitor C2 can reach the power battery voltage Vbat.

[0072] Furthermore, such as Figure 2 As shown, the auxiliary pre-charge circuit 130 includes an auxiliary pre-charge branch 131 and an auxiliary positive contactor K5 connected in parallel, and the auxiliary pre-charge branch 131 includes an auxiliary pre-charge resistor R5 and an auxiliary pre-charge contactor K6 connected in series.

[0073] Specifically, one end of the auxiliary precharge branch 131 and the auxiliary positive contactor K5 connected in parallel is connected to the BOP device 150, and the other end is connected to the second positive terminal Uo+ of the power battery 300. The end of the auxiliary precharge resistor R5 not connected to the auxiliary precharge contactor K6 is connected to the BOP device 150, and the end of the auxiliary precharge contactor K6 not connected to the auxiliary precharge resistor R5 is connected to the second positive terminal Uo+ of the power battery 300. By default, both the auxiliary positive contactor K5 and the auxiliary precharge contactor K6 are in the open state. After the controller 140 receives a standby command input by the user, it can control the main negative contactor K2 to close, and then control the auxiliary precharge contactor K6 to close. The current generated by the power battery 300 flows into the output bus capacitor and also into the BOP device 150 to precharge the BOP device 150. After the BOP device 150 has finished precharging, it controls the auxiliary positive contactor K5 to close and the auxiliary precharge contactor K6 to open. At this point, the voltage of the BOP device 150 can reach the power battery voltage Vbat.

[0074] Furthermore, the boost DC / DC converter 110 includes multiple interleaved parallel BOOST boost circuits 111; each of the BOOST boost circuits 111 is connected to the controller 140; the controller 140 is used to perform phase-shift control on each of the BOOST boost circuits 111 based on the PWM signal.

[0075] Specifically, the first terminal of each BOOST boost circuit 111 is connected to the first positive terminal Ui+ of the fuel cell stack 200, and the second terminal of each BOOST boost circuit 111 is connected to the first negative terminal Ui- of the fuel cell stack 200, the second terminal of the output bus capacitor C2, and the first terminal of the main negative contactor K2. The system is non-isolated and shares a common negative terminal. The third terminal of each BOOST boost circuit 111 is connected to the first terminal of the output bus capacitor and the first terminal of the main pre-charge circuit 120. The second terminal of the main pre-charge circuit 120 is connected to the second positive terminal Uo+ of the power battery 300, and the second terminal of the main negative contactor K2 is connected to the second negative terminal Uo- of the power battery 300. The controller 140 can perform phase-shift control on each BOOST boost circuit 111 according to the PWM control signal to convert the voltage Vc1 of the fuel cell stack 200 into an output voltage to charge the power battery 300. The boost DC / DC converter 110, composed of all BOOST boost circuits 111, provides closed-loop control of the voltage, current, and power of the fuel cell system.

[0076] Optionally, the output of the fuel cell stack 200 is directly connected to the boost DC / DC converter 110 via a copper busbar.

[0077] Furthermore, the circuit structures of each BOOST boost circuit 111 are identical. Figure 3 This is a schematic diagram of the BOOST boost circuit provided in an embodiment of the present invention, as shown below. Figure 3 As shown, the BOOST boost circuit 111 includes: inductor L1, diode D1, and MOSFET Q1, wherein:

[0078] The first terminal of inductor L1 serves as the first terminal of BOOST boost circuit 111. The second terminal of inductor L1 is connected to the anode of diode D1 and the drain of MOSFET Q1. The cathode of diode D1 serves as the third terminal of BOOST boost circuit 111. The source of MOSFET Q1 serves as the third terminal of BOOST boost circuit 111. The gate of MOSFET Q1 is used to receive the control signal input by controller 140.

[0079] Furthermore, Figure 4 This is a circuit diagram of the fuel cell system startup circuit provided in an embodiment of the present invention, as shown below. Figure 4 As shown, the fuel cell system startup circuit also includes a bus resistor R2, which is connected in parallel across the output bus capacitor.

[0080] The fuel cell stack 200 may also include a discharge circuit 160 and an input support capacitor branch 170 between it and the boost DC / DC converter 110. The discharge circuit 160 includes a third switch K3 and a third resistor R3 connected in series, and is connected between the first positive terminal Ui+ and the first negative terminal Ui- of the fuel cell stack 200. The discharge circuit 160 provides a safe release path for the remaining energy output by the fuel cell stack 200, preventing excessive voltage accumulation in the fuel cell stack 200 when it is not in operation, thereby protecting the fuel cell stack 200 and the equipment connected to it from damage. The input support capacitor branch 170 includes a first capacitor C1 and a first resistor R1 connected in parallel, and is also connected in parallel between the first positive terminal Ui+ and the first negative terminal Ui- of the fuel cell stack 200. The input support capacitor branch 170 is used to connect the input of the boost DC / DC converter 110 and the output of the fuel cell stack 200, reducing voltage and current ripple impacts, acting as a filter and buffer, and ensuring the safe and reliable start-up and operation of the fuel cell system.

[0081] Furthermore, the controller 140 is also communicatively connected to the vehicle CAN network 230. The controller 140 is also used to receive the power battery voltage transmitted by the vehicle CAN network 230, and to sample and obtain the bus voltage and the stack voltage 200.

[0082] Specifically, Figure 5 This is a connection diagram of the fuel cell system provided in an embodiment of the present invention, as shown below. Figure 5 As shown, the fuel cell system includes the aforementioned fuel cell system start-up circuit, fuel cell stack 200, BOP device 150, fuel cell control unit (FCU) 220, and fuel cell CAN network 210. The fuel cell CAN network 210 is communicatively connected to the fuel cell stack 200, FCU, BOP device 150, air compressor controller 180, and vehicle CAN network 230. The vehicle CAN network 230 is communicatively connected to the power battery 300. The controller 140 can obtain the power battery voltage and sample the bus voltage, fuel cell stack 200 voltage, and input / output current through the fuel cell CAN network 210 and vehicle CAN network 230. The fuel cell control unit 220 can adjust the operating parameters of the BOP device 150 in real time through the fuel cell CAN network 210. For example, the fuel cell control unit 220 can control the hydrogen supply rate of the hydrogen pump and ejector, and control the speed of the cooling fan through the fuel cell CAN network 210. The fuel cell control unit 220 can obtain information such as voltage and current of the individual cells in the fuel cell stack 200 through the fuel cell CAN network 210, determine whether the single cell consistency condition of the fuel cell stack 200 is met, and feed back the determination result to the controller 140.

[0083] The fuel cell system startup circuit provided in this invention independently controls the main pre-charge circuit and the auxiliary pre-charge circuit, respectively managing the pre-charge and power supply of the output bus capacitor and the BOP device. After pre-charging is completed and the power battery voltage is lower than the open-circuit voltage of the stack, the startup of the fuel cell system is achieved by controlling the change of the bus voltage of the output bus capacitor between the power battery voltage and the open-circuit voltage, and by the chopping operation of the boost DC / DC converter. This invention uses a boost DC / DC converter instead of a buck-boost topology. By controlling the dynamic change of the bus voltage between the power battery voltage and the open-circuit voltage, and by the chopping operation of the boost DC / DC converter, the fuel cell system can be started smoothly. This saves the use of a large number of electronic components required for the buck module in the buck-boost topology, thereby significantly reducing equipment costs, size, and weight, and making control simpler, more reliable, and more efficient.

[0084] This invention also provides a fuel cell system startup method, applied to the fuel cell system startup circuit described in any of the preceding embodiments. Figure 6 This is one of the flowcharts illustrating the fuel cell system startup method provided in this embodiment of the invention, such as... Figure 6 As shown, the method includes steps 610 to 640.

[0085] Step 610: Control the on / off state of the main pre-charging circuit to independently pre-charge the output bus capacitor, and control the on / off state of the auxiliary pre-charging circuit to independently pre-charge and manage the power supply of the BOP device; after the pre-charging is completed, the bus voltage of the output bus capacitor is the power battery voltage.

[0086] Step 620: When the pre-charging of the output bus capacitor and the BOP device is completed, and the open-circuit voltage of the stack is higher than the voltage of the power battery, the connection between the stack and the power battery is disconnected, and the stack voltage of the stack, together with the bus voltage, is controlled to rise to the open-circuit voltage.

[0087] Step 630: After the single-cell consistency condition of the fuel cell stack is met, close the main pre-charge contactor in the main pre-charge circuit, and pull down the fuel cell stack voltage and the bus voltage to the power battery voltage through the main pre-charge resistor in the main pre-charge circuit.

[0088] Step 640: Close the main positive contactor in the main pre-charge circuit, open the main pre-charge contactor, and control the chopper operation of the boost DC / DC converter to reduce the stack voltage to the rated voltage, thereby completing the start-up of the fuel cell system.

[0089] Specifically, Figure 7 This is the second schematic flowchart of the fuel cell start-up method provided in this embodiment of the invention. Figure 8This is a schematic diagram of voltage changes during the startup process of a fuel cell system provided in an embodiment of the present invention, as shown below. Figure 7 and Figure 8 As shown, the power-on startup process of the fuel cell system includes the following steps S1 to S6.

[0090] S1. Pre-charge stage: Close the main negative contactor K2, main pre-charge contactor K4, and auxiliary pre-charge contactor K6 to independently pre-charge and manage the power supply of the output bus capacitor and BOP device of the boost DC / DC converter. After pre-charging, the output bus capacitor and BOP device are pre-charged to the power battery voltage. Then, close the main positive contactor K1 and auxiliary positive contactor K5, and open the main pre-charge contactor K4 and auxiliary pre-charge contactor K6 to allow the BOP device to continue working and provide a stable reaction environment for the fuel cell stack.

[0091] S2. After the output bus capacitor and BOP device pre-charge is completed, obtain the power battery voltage and determine whether the power battery voltage Vbat is higher than the open circuit voltage Voc of the stack.

[0092] S3. If the open-circuit voltage Voc is lower than the power battery voltage Vbat, control the boost DC / DC converter to operate, output power to the power system, and pull the stack voltage up to the rated voltage.

[0093] S4. Battery Stack Start-up Stage: If the open-circuit voltage Voc is higher than the power battery voltage Vbat, the controller can disconnect the connection between the battery stack and the power battery, and the battery stack enters the start-up stage. After the battery stack enters the start-up stage, as the electrochemical reaction within the battery stack proceeds, charge continuously accumulates at the positive and negative electrodes, and the battery stack voltage Vc1 gradually increases until it reaches the power battery voltage Vbat. During this process, due to the reverse blocking of diode D1 in the boost DC / DC converter and the main pre-charge circuit being in an open state, the output bus capacitor C2 can only discharge slowly through the bus resistor R2. For a short period of time, the bus voltage Vc2 remains approximately near the power battery voltage Vbat.

[0094] S5, Open-Circuit Voltage Rise Stage: As the charge on the positive and negative electrodes of the fuel cell stack continues to accumulate, the stack voltage Vc1 continues to rise. When the stack voltage Vc1 equals the bus voltage Vc2, a small amount of charge in the stack will be output to the output bus capacitor for charging. Since the capacitance of the output bus capacitor C2 is small and the main pre-charge circuit is in the open state, the bus voltage Vc2 will continue to rise to near the open-circuit voltage Voc. At this time, the main positive contactor K1 is in the open state, and the stack voltage Vc1 will not be clamped at the power battery voltage Vbat by the large-capacity power battery, thus preventing the stack from experiencing a "single low" fault or a "reverse polarity" fault. The stack voltage Vc1 can continue to rise to near the open-circuit voltage Voc and remain there briefly.

[0095] S6, BOOST Loading Stage: After each individual cell in the fuel cell stack meets the stack-wide consistency condition, the stack voltage Vc1 can be rapidly controlled for loading. Specifically, as the bus voltage Vc2 rises to near the open-circuit voltage Voc, it is already higher than the power battery voltage Vbat. At this point, the main pre-charge contactor K4 can be closed, allowing the output bus capacitor C2 to discharge through the main pre-charge branch. Under the action of the pre-charge resistor R4, no surge current is generated during the discharge process, and the bus voltage Vc2 is pulled down again to near the power battery voltage Vbat. Afterwards, the bus voltage Vc2 is continuously monitored. If the bus voltage Vc2 is detected to be equal to the power battery voltage Vbat within a continuous time period, the main positive contactor K1 is closed, and the main pre-charge contactor K4 is opened. At this time, the controller can control the boost DC / DC converter to operate in a chopper mode, reducing the stack voltage until it reaches the rated voltage, thus completing the startup of the fuel cell system.

[0096] It's important to note that a "single low voltage" fault in a fuel cell stack refers to a situation where the voltage of one or more individual cells falls below the normal operating voltage. A "single low voltage" fault can lead to performance degradation in surrounding cells and even affect the overall performance and lifespan of the fuel cell stack. A "reverse polarity" fault occurs when the voltage of a single cell falls below zero volts during stack operation, meaning the polarity of the anode and cathode of that cell reverses. Reverse polarity not only causes severe corrosion of the anode catalyst but can also lead to corrosion of the metal bipolar plates, thereby accelerating battery performance degradation and potentially causing irreversible damage to the fuel cell stack.

[0097] Furthermore, controlling the chopping operation of the boost DC / DC converter to reduce the voltage of the fuel cell stack to the rated voltage includes:

[0098] By controlling the duty cycle of the boost DC / DC converter, the output current of the fuel cell stack is increased to reduce the fuel cell stack voltage until the fuel cell stack voltage is reduced to the rated voltage.

[0099] Specifically, in step S6 above, a control signal can be input to the gate of the MOS transistor Q1 in the BOOST boost circuit to control the BOOST boost circuit to operate in a chopping manner, that is, to control the duty cycle of the BOOST boost circuit, thereby controlling the increase of the fuel cell stack's output current. Based on the fuel cell stack's output characteristics, the increase in output current will cause the fuel cell stack's output voltage Vc1 to decrease until it drops to the rated voltage, thus completing the fuel cell startup.

[0100] It should be noted that this control signal can be a PWM (Pulse Width Modulation) signal. By adjusting the duty cycle of this control signal, the on / off frequency and duty cycle of the MOSFET Q1 can be adjusted, thereby controlling the output load and increasing the output current of the fuel cell stack. When the MOSFET Q1 is on, the output current of the fuel cell stack is stored in the inductor L1. When the MOSFET Q1 is off, the inductor L1 releases energy, and the provided current flows to the power battery through the diode D1 and the main positive contactor K1.

[0101] Furthermore, disconnecting the fuel cell stack from the power battery includes:

[0102] Disconnect the main positive contactor and the main precharge branch.

[0103] Specifically, in step S4 above, the controller can control the main positive contactor K1 to disconnect. At this time, the main pre-charge circuit is in a disconnected state, thereby disconnecting the connection between the fuel cell stack and the power battery.

[0104] The fuel cell system startup method provided in this invention independently controls the main pre-charge circuit and the auxiliary pre-charge circuit, pre-charging the output bus capacitor and BOP device respectively. When the power battery voltage is lower than the open-circuit voltage of the fuel cell, the connection between the stack and the power battery is disconnected, controlling the stack voltage and the bus voltage to rise to the open-circuit voltage. After meeting the single-cell consistency condition of the stack, the main pre-charge contactor is closed, and the stack voltage and bus voltage are pulled down from the open-circuit voltage to the power battery voltage through the main pre-charge resistor. Then, the main positive contactor is closed, the main pre-charge contactor is opened, and the boost DC / DC converter is controlled to operate in chopping mode, further pulling the stack voltage down to the rated voltage, thus completing the startup of the fuel cell system. When the open-circuit voltage of the fuel cell is higher than the power battery voltage, this invention embodiment can smoothly start the fuel cell and transition to the rated operating state through simple timing control. Compared with the buck-boost topology, it saves the use of general half-power devices, thereby significantly reducing equipment costs, equipment size and weight, and providing simple, reliable, and efficient control.

[0105] Figure 9 This is a schematic diagram of the logic topology of the controller provided in an embodiment of the present invention, such as... Figure 9 As shown, the controller may include: a processor 910, an ADC sampling module 920, a memory 930, a CAN communication module 940, a communication interface 950, a PWM module 960, a bus 970, and a computer program stored in the memory and executable on the processor. The processor 910, the ADC sampling module 920, the memory 930, the CAN communication module 940, the PWM module 960, and the communication interface 950 are all connected via the bus.

[0106] The CAN communication module 940 is connected to the vehicle's CAN network, and the CAN communication module 940 is used to obtain the power battery voltage;

[0107] The ADC sampling module 920 is used to collect the bus voltage and stack voltage corresponding to the output bus capacitor;

[0108] The PWM module 960 is used to generate control signals, which are used to control the chopper operation of the boost DC / DC converter.

[0109] When the processor 910 executes the computer program, it implements the fuel cell system startup method as described in any of the preceding claims. The method includes:

[0110] The on / off state of the main pre-charging circuit is controlled to independently pre-charge the output bus capacitor, and the on / off state of the auxiliary pre-charging circuit is controlled to independently pre-charge and manage the power supply of the BOP device; after the pre-charging is completed, the bus voltage of the output bus capacitor is the power battery voltage.

[0111] When the pre-charging of the output bus capacitor and the BOP device is completed, and the open-circuit voltage of the stack is higher than the voltage of the power battery, the connection between the stack and the power battery is disconnected, and the stack voltage of the stack, together with the bus voltage, is controlled to rise to the open-circuit voltage.

[0112] After the single-cell consistency condition of the fuel cell stack is met, the main pre-charge contactor in the main pre-charge circuit is closed, and the fuel cell stack voltage and the bus voltage are pulled down to the power battery voltage through the main pre-charge resistor in the main pre-charge circuit.

[0113] Close the main positive contactor in the main pre-charge circuit, open the main pre-charge contactor, and control the chopper operation of the boost DC / DC converter to reduce the stack voltage to the rated voltage, thus completing the start-up of the fuel cell system.

[0114] The communication interface 950 in the controller can be a digital I / O (Input / Output) interface for transmitting digital signals. The aforementioned memory 930 may include RAM (Random Access Memory) and FLASH memory. The logical instructions of the memory 930 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory, magnetic disks, or optical disks.

[0115] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer is able to execute the fuel cell system startup method provided by the above methods, the method comprising:

[0116] The on / off state of the main pre-charging circuit is controlled to independently pre-charge the output bus capacitor, and the on / off state of the auxiliary pre-charging circuit is controlled to independently pre-charge and manage the power supply of the BOP device; after the pre-charging is completed, the bus voltage of the output bus capacitor is the power battery voltage.

[0117] When the pre-charging of the output bus capacitor and the BOP device is completed, and the open-circuit voltage of the stack is higher than the voltage of the power battery, the connection between the stack and the power battery is disconnected, and the stack voltage of the stack, together with the bus voltage, is controlled to rise to the open-circuit voltage.

[0118] After the single-cell consistency condition of the fuel cell stack is met, the main pre-charge contactor in the main pre-charge circuit is closed, and the fuel cell stack voltage and the bus voltage are pulled down to the power battery voltage through the main pre-charge resistor in the main pre-charge circuit.

[0119] Close the main positive contactor in the main pre-charge circuit, open the main pre-charge contactor, and control the chopper operation of the boost DC / DC converter to reduce the stack voltage to the rated voltage, thus completing the start-up of the fuel cell system.

[0120] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the fuel cell system startup method provided by the methods described above, the method comprising:

[0121] The on / off state of the main pre-charging circuit is controlled to independently pre-charge the output bus capacitor, and the on / off state of the auxiliary pre-charging circuit is controlled to independently pre-charge and manage the power supply of the BOP device; after the pre-charging is completed, the bus voltage of the output bus capacitor is the power battery voltage.

[0122] When the pre-charging of the output bus capacitor and the BOP device is completed, and the open-circuit voltage of the stack is higher than the voltage of the power battery, the connection between the stack and the power battery is disconnected, and the stack voltage of the stack, together with the bus voltage, is controlled to rise to the open-circuit voltage.

[0123] After the single-cell consistency condition of the fuel cell stack is met, the main pre-charge contactor in the main pre-charge circuit is closed, and the fuel cell stack voltage and the bus voltage are pulled down to the power battery voltage through the main pre-charge resistor in the main pre-charge circuit.

[0124] Close the main positive contactor in the main pre-charge circuit, open the main pre-charge contactor, and control the chopper operation of the boost DC / DC converter to reduce the stack voltage to the rated voltage, thus completing the start-up of the fuel cell system.

[0125] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0126] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as FLASH, ROM / RAM, magnetic disk, optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods of various embodiments or some parts of embodiments.

[0127] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A start-up circuit for a fuel cell system, characterized in that, include: The system comprises a controller, a boost DC / DC converter, an output bus capacitor, a main pre-charge circuit, and an auxiliary pre-charge circuit, wherein: The input terminal of the boost DC / DC converter is connected to the battery stack, and the output terminal of the boost DC / DC converter is connected to the power battery through the output bus capacitor and the main pre-charge circuit; the main pre-charge circuit includes a main pre-charge branch and a main positive contactor connected in parallel; The BOP device, which serves as an auxiliary device for the fuel cell stack, is connected to the power battery via the auxiliary pre-charging circuit. The controller is used to independently pre-charge and power supply the output bus capacitor of the boost DC / DC converter and the BOP device, and after pre-charging, the bus voltage of the output bus capacitor is the power battery voltage; it is also used to control the change between the power battery voltage and the open circuit voltage of the output bus capacitor and the chopper operation of the boost DC / DC converter, and to complete the startup of the fuel cell system, when the open circuit voltage of the fuel cell stack is higher than the power battery voltage after pre-charging. The controller controls the change of the bus voltage of the output bus capacitor between the power battery voltage and the open-circuit voltage, and the chopping operation of the boost DC / DC converter to complete the startup of the fuel cell system, including: The auxiliary pre-charging circuit is kept on to control the BOP device to continue operating; By disconnecting the fuel cell stack from the power battery, the fuel cell stack voltage and the bus voltage of the output bus capacitor are controlled to rise to the open circuit voltage. After meeting the single-cell consistency condition of the fuel cell stack, the stack voltage and the bus voltage are controlled to decrease from the open-circuit voltage to the power battery voltage. By controlling the chopper operation of the boost DC / DC converter, the voltage of the fuel cell stack is reduced from the voltage of the power battery to the rated voltage, thus completing the start-up of the fuel cell.

2. The fuel cell system start-up circuit according to claim 1, characterized in that, The main precharge branch includes a main precharge resistor and a main precharge contactor connected in series.

3. The fuel cell system start-up circuit according to claim 1, characterized in that, The auxiliary pre-charge circuit includes an auxiliary pre-charge branch and an auxiliary positive contactor connected in parallel, and the auxiliary pre-charge branch includes an auxiliary pre-charge resistor and an auxiliary pre-charge contactor connected in series.

4. The fuel cell system start-up circuit according to claim 1, characterized in that, The boost DC / DC converter includes multiple interleaved parallel BOOST boost circuits; each of the BOOST boost circuits is connected to the controller; the controller is used to perform phase-shift control on each of the BOOST boost circuits based on PWM signals.

5. The fuel cell system start-up circuit according to any one of claims 1-4, characterized in that, The controller is also connected to the vehicle's CAN network for communication. The controller is also used to receive the power battery voltage transmitted by the vehicle's CAN network and to sample and obtain the bus voltage and the stack voltage.

6. A method for starting a fuel cell system, characterized in that, The method, applied to the start-up circuit of a fuel cell system as described in any one of claims 1-5, comprises: The on / off state of the main pre-charging circuit is controlled to independently pre-charge the output bus capacitor, and the on / off state of the auxiliary pre-charging circuit is controlled to independently pre-charge and manage the power supply of the BOP device; after the pre-charging is completed, the bus voltage of the output bus capacitor is the power battery voltage. When the pre-charging of the output bus capacitor and the BOP device is completed, and the open-circuit voltage of the stack is higher than the voltage of the power battery, the connection between the stack and the power battery is disconnected, and the stack voltage of the stack, together with the bus voltage, is controlled to rise to the open-circuit voltage. After the single-cell consistency condition of the fuel cell stack is met, the main pre-charge contactor in the main pre-charge circuit is closed, and the fuel cell stack voltage and the bus voltage are pulled down to the power battery voltage through the main pre-charge resistor in the main pre-charge circuit. Close the main positive contactor in the main pre-charge circuit, open the main pre-charge contactor, and control the chopper operation of the boost DC / DC converter to reduce the stack voltage to the rated voltage, thus completing the start-up of the fuel cell system.

7. The fuel cell system start-up method according to claim 6, characterized in that, The step of controlling the chopping operation of the boost DC / DC converter to reduce the voltage of the fuel cell stack to the rated voltage includes: By controlling the duty cycle of the boost DC / DC converter, the output current of the fuel cell stack is increased to reduce the fuel cell stack voltage until the fuel cell stack voltage is reduced to the rated voltage.

8. The fuel cell system start-up method according to claim 6, characterized in that, Disconnecting the fuel cell stack from the power battery includes: Disconnect the main positive contactor and the main precharge branch.

9. A controller, comprising a processor, an ADC sampling module, a memory, a CAN communication module, a communication interface, a PWM module, and a computer program stored in the memory and executable on the processor, characterized in that, The processor, the ADC sampling module, the memory, the CAN communication module, the PWM module, and the communication interface are all connected via a bus; The CAN communication module is connected to the vehicle's CAN network, and the CAN communication module is used to obtain the power battery voltage; The ADC sampling module is used to acquire the bus voltage and stack voltage corresponding to the output bus capacitor; The PWM module is used to generate control signals, which are used to control the chopping operation of the boost DC / DC converter. When the processor executes the computer program, it implements the fuel cell system startup method as described in any one of claims 6-8.

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