Fuel cell system starting circuit, method and controller

Abstract

The invention relates to the technical field of fuel cells, and provides a fuel cell system starting circuit and method and a controller, the circuit comprises a controller, a boost DC / DC converter, an output bus capacitor, a main pre-charging circuit and an auxiliary pre-charging circuit, the output end of the boost DC / DC converter is connected with the power battery through the output bus capacitor and the main pre-charging circuit; the BOP equipment is connected with the power battery through the auxiliary pre-charging circuit; the controller is used for carrying out independent pre-charging and power supply management on the output bus capacitor of the boost DC / DC converter and the BOP device, and the bus voltage of the output bus capacitor after pre-charging is finished is the voltage of the power battery. According to the invention, effective control of the voltage and current of the electric pile in the starting process of the fuel cell system can be realized, power devices additionally required by the buck-boost topology are saved, the equipment cost, the equipment volume and the equipment weight are reduced, and the efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to a fuel cell system starting circuit, method and controller. Background Art

[0002] The development of high-power fuel cell systems suitable for medium and heavy-duty trucks is an irresistible trend. At present, the installed power demand of heavy-duty trucks is at the 240kW level. For example, a hydrogen fuel heavy-duty truck installation scenario is: the fuel cell system adopts a 550-cell single stack structure, with an open circuit voltage of about 560V, an idle voltage of about 451V, and a rated voltage of about 355V; the power battery system adopts a 600V platform with a voltage range of 450V to 750V. Since there is an overlap between the output voltage range of the stack and the voltage range of the power battery, the DC / DC Converter for Fuel Cell (DCF) integrated in the power controller (PCU) of the fuel cell system needs to adopt a multi-channel staggered parallel four-tube buck-boost topology to achieve full-range power conversion control.

[0003] However, the multi-channel staggered parallel four-tube buck-boost topology uses a large number of electronic components such as power switching tubes and diodes, which greatly increases the equipment cost, equipment volume and equipment weight, and has high control complexity and low system efficiency. Summary of the invention

[0004] The present invention provides a fuel cell system starting circuit, method and controller to solve the defects of the prior art that a large number of power devices are used, the cost is high, the volume and weight are increased, the control complexity is high, and there are many links and low efficiency.

[0005] The present invention provides a fuel cell system startup 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 to the battery stack, and the output end of the boost DC / DC converter is connected to the power battery through the output bus capacitor and the main pre-charging circuit; A BOP device as an auxiliary device of the battery stack is connected to the power battery through 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 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 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 after the pre-charging is completed and the open circuit voltage of the battery stack is higher than the power battery voltage, to complete the startup of the fuel cell system.

[0006] According to the fuel cell system startup circuit provided by the present invention, the controller controls the bus voltage of the output bus capacitor to change between the power battery voltage and the open circuit voltage, and the chopper operation of the boost DC / DC converter to complete the startup of the fuel cell system, including: Controlling the auxiliary pre-charging circuit to remain turned on, so as to control the BOP device to continue to work; By disconnecting the battery stack from the power battery, controlling the battery stack voltage and the bus voltage of the output bus capacitor to increase to the open circuit voltage; After the battery stack single cell consistency condition is met, controlling the battery stack voltage and the bus voltage to decrease from the open circuit voltage to the power battery voltage; The startup of the fuel cell is completed by controlling the chopper operation of the boost DC / DC converter to control the voltage of the fuel cell stack to decrease from the power battery voltage to the rated voltage.

[0007] According to the fuel cell system startup circuit provided by the present invention, the main pre-charging circuit includes a main pre-charging branch and a main positive contactor connected in parallel, and the main pre-charging branch includes a main pre-charging resistor and a main pre-charging contactor connected in series.

[0008] According to the fuel cell system startup circuit provided by the present invention, the auxiliary pre-charging circuit includes an auxiliary pre-charging branch and an auxiliary positive contactor connected in parallel, and the auxiliary pre-charging branch includes an auxiliary pre-charging resistor and an auxiliary pre-charging contactor connected in series.

[0009] According to the fuel cell system startup circuit provided by the present invention, the boost DC / DC converter includes multiple BOOST boost circuits connected in parallel; each of the BOOST boost circuits is connected to the controller; and the controller is used to perform staggered phase control on each of the BOOST boost circuits based on a PWM signal.

[0010] According to the fuel cell system starting circuit provided by the present invention, the controller is also connected to the vehicle CAN network for communication, and the controller is also used to receive the power battery voltage transmitted by the vehicle CAN network, and sample and obtain the bus voltage and the stack voltage.

[0011] The present invention further provides a fuel cell system startup method, which is applied to any of the fuel cell system startup circuits described above, and the method comprises: 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 power supply management the BOP equipment; 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 battery stack is higher than the voltage of the power battery, disconnecting the battery stack from the power battery to control the battery stack voltage together with the bus voltage to increase to the open circuit voltage; After the battery stack single-cell consistency condition is met, the main pre-charging contactor in the main pre-charging circuit is closed, and the battery stack voltage and the bus voltage are pulled down to the power battery voltage through the main pre-charging resistor in the main pre-charging circuit; The main positive contactor in the main pre-charging circuit is closed, and the main pre-charging contactor is opened. By controlling the chopping operation of the boost DC / DC converter, the stack voltage is controlled to drop to the rated voltage, thereby completing the startup of the fuel cell system.

[0012] According to the fuel cell system startup method provided by the present invention, the stack voltage is controlled to be reduced to the rated voltage by controlling the chopper operation of the boost DC / DC converter, comprising: By controlling the duty cycle of the boost DC / DC converter, the output current of the battery stack is controlled to increase so as to reduce the battery stack voltage until the battery stack voltage is reduced to the rated voltage.

[0013] According to the fuel cell system startup method provided by the present invention, disconnecting the fuel cell stack from the power battery includes: Disconnect the main positive contactor and the main pre-charge branch.

[0014] The present invention also provides 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, wherein the processor, the ADC sampling module, the memory and 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 CAN network, and the CAN communication module is used to obtain the power battery voltage; The ADC sampling module is used to collect the bus voltage and the stack voltage corresponding to the output bus capacitance; The PWM module is used to generate a control signal, and the control signal is used to control the chopping operation of the boost DC / DC converter; When the processor executes the computer program, the fuel cell system startup method as described in any one of the above items is implemented.

[0015] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the fuel cell system startup method described in any one of the above is implemented.

[0016] The present invention also provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the fuel cell system startup method described in any one of the above is implemented.

[0017] The fuel cell system startup circuit, method and controller provided by the present invention independently control the main pre-charging circuit and the auxiliary pre-charging circuit, respectively perform independent pre-charging and power supply management on the output bus capacitor and the BOP device, and after the pre-charging is completed and the power battery voltage is lower than the open circuit voltage of the battery stack, the start-up of the fuel cell system is completed by controlling the bus voltage of the output bus capacitor to change between the power battery voltage and the open circuit voltage, and the chopping operation of the boost DC / DC converter. In the present invention, the boost DC / DC converter replaces the buck-boost topology, controls the bus voltage to change dynamically between the power battery voltage and the open circuit voltage, and the chopping operation of the boost DC / DC converter, so that the fuel cell system can be started smoothly, saving the use of a large number of electronic components required for the buck module in the buck-boost topology, thereby greatly reducing the equipment cost, reducing the equipment volume and weight, and the control is simpler and more reliable, and the efficiency is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a connection diagram of a fuel cell system starting circuit provided by an embodiment of the present invention.

[0020] Figure 2 It is a partial schematic diagram of a fuel cell system startup circuit provided by an embodiment of the present invention.

[0021] Figure 3 It is a topological schematic diagram of a BOOST boost circuit provided in an embodiment of the present invention.

[0022] Figure 4Schematic diagram of a fuel cell system startup circuit provided in an embodiment of the present invention.

[0023] Figure 5 Schematic diagram of the connection of a fuel cell system provided by an embodiment of the present invention.

[0024] Figure 6 This is one of the flow charts of the fuel cell startup method provided in an embodiment of the present invention.

[0025] Figure 7 This is the second flow chart of the fuel cell startup method provided in the embodiment of the present invention.

[0026] Figure 8 It is a schematic diagram of voltage changes during the startup process of a fuel cell provided by an embodiment of the present invention.

[0027] Fig. 9 It is a schematic diagram of the logical topology of the controller provided by an embodiment of the present invention.

[0028] Reference numerals: 110: Boost DC / DC converter; 111: BOOST boost circuit; 120: Main pre-charging circuit; 121: Main pre-charging branch; 130: Auxiliary pre-charging circuit; 131: Auxiliary pre-charging branch; 140: Controller; 150: BOP equipment; 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 DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] In a hydrogen fuel heavy-duty truck installation scenario, the stack adopts a 550-cell single stack structure, with an open circuit voltage Voc of approximately 560V, an idle voltage of approximately 451V, and a rated voltage of approximately 355V; the power battery system adopts a 600V platform with a voltage range of 450V to 750V. Due to the overlap between the stack output voltage range and the power battery voltage range, the fuel cell DC / DC Converter for Fuel Cell (DCF) integrated in the fuel cell system power controller (PCU) needs to adopt a multi-path interleaved parallel buck-boost topology to achieve full-range power conversion control.

[0031] However, in general, the vehicle control unit (VCU) will control the SOC (State Of Charge) range of the power battery. The power battery voltage Vbat of the power battery can only be reduced to 450V under extreme conditions such as long-term storage, power loss and low temperature, and rarely reduced to around 450V under other conditions. After the battery stack is started, the DCF continues to output a large current to keep the output voltage Vc1 of the battery stack at a low level. In other words, only when the power battery voltage Vbat of the power battery is reduced to about 450V, the buck module in the buck-boost topology will be put into use. Under other conditions, the switch tube of the buck module remains in the on state and does not play a buck role, resulting in a waste of resources.

[0032] The buck-boost topology uses a large number of electronic components such as power switching tubes and diodes, which greatly increases the equipment cost, equipment volume and equipment weight, and has a high control complexity, thereby reducing control efficiency.

[0033] In view of the above problems in the prior art, an embodiment of the present invention provides a fuel cell system starting circuit. Figure 1 FIG. 1 is a connection diagram of a fuel cell system startup circuit provided by an embodiment of the present invention. 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-charging circuit 120 and an auxiliary pre-charging circuit 130 .

[0034] The input end of the boost DC / DC converter 110 is connected to the battery stack 200 , and the output end of the boost DC / DC converter 110 is connected to the power battery 300 via the output bus capacitor and the main pre-charging circuit 120 .

[0035] A BOP (Balance Of Plant) device, which is an auxiliary device of the fuel cell stack 200 , is connected to the power battery 300 through the auxiliary pre-charging circuit 130 .

[0036] 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, 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 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 after the pre-charging is completed and the open circuit voltage of the battery stack 200 is higher than the power battery voltage, to complete the startup of the fuel cell system.

[0037] It should be noted that the source of electrical energy for the fuel cell system is the stack 200, which is an energy conversion device that converts the chemical energy of fuel and oxidant into electrical energy through electrochemical reactions. The stack 200 is composed of a plurality of single cells connected in series, and the fuel and oxidant react in the stack 200 to convert chemical energy into electrical energy. The power battery 300 is an energy storage device that stores electrical energy through chemical reactions and releases electrical energy when needed. After the fuel cell system generates electrical energy, the output of the boost DC / DC converter 110 is connected to the power battery 300, and the electrical energy can be stored in the power battery 300. The output voltage of the fuel cell system is the power battery voltage.

[0038] The boost DC / DC converter 110 is a key component in the fuel cell system, and is used to boost the voltage Vc1 of the stack 200, so as to realize the energy flow between the stack 200 and the power battery 300 in a wide voltage range, that is, to realize charging of the power battery 300. The boost DC / DC converter 110 realizes the boost through the BOOST boost circuit 111, which is a switching power converter that can convert a lower input voltage into a higher output voltage.

[0039] The BOP equipment 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 stack 200, wherein the air compressor is used to provide the necessary oxygen for the stack 200. The water pump is used to control the moisture content inside the stack 200. The PTC heater and the cooling fan are used to maintain the temperature of the stack 200. The hydrogen pump and the ejector are used to provide the required hydrogen for the stack 200. In addition, the fuel cell system startup circuit also includes an air compressor controller 180 and a BOP PDU (Power Distribution Unit) 190. The auxiliary pre-charging circuit 130 is connected to the air compressor through the air compressor controller 180, and the BOP PDU 190 is respectively connected to the PTC heater, the cooling fan, the hydrogen pump, and the ejector, and is used to distribute power to the PTC heater, the cooling fan, the hydrogen pump, and the ejector, thereby maintaining a stable working state.

[0040] In the embodiment of the present invention, the main pre-charging circuit 120 and the auxiliary pre-charging circuit 130 are both pre-charging circuits and operate independently. After receiving the standby command input by the user, the controller 140 can control the main pre-charging circuit 120 to conduct for pre-charging the output bus capacitor, and at the same time, control the auxiliary pre-charging circuit 130 to conduct for pre-charging the BOP device 150, ensuring that the output bus capacitor and the BOP device 150 reach a safe operating voltage before the stack 200 is started, avoiding the output bus capacitor directly connected to the stack 200 and the power battery 300 when not charged, and avoiding the instantaneous large current from damaging the sensitive electronic components in the BOP device 150, reducing the safety risk during the startup of the stack 200, and providing guarantee for the smooth startup of the fuel cell system.

[0041] When the controller 140 receives the pre-charging end signals 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, which can minimize the over-discharge in the initial startup phase of the battery stack 200 and reduce the charging and discharging surge current caused by the difference between the power battery voltage and the battery stack voltage. In addition, the pre-charging can also shorten the startup time of the battery stack 200.

[0042] After receiving the start command input by the user, the controller 140 can determine whether the power battery voltage Vbat is lower than the open circuit voltage Voc of the stack 200. If the power battery voltage Vbat is higher than or equal to the open circuit voltage Voc, the voltage Vc1 of the stack 200 can be boosted by 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 stack 200 enters the start-up stage. By controlling the bus voltage of the output bus capacitor to dynamically change between the power battery voltage and the open circuit voltage, and controlling the boost DC / DC converter 110 to chop operation, the fuel cell system is smoothly transitioned to the BOOST operation mode to achieve the start-up of the fuel cell system.

[0043] It should be noted that the controller 140 can determine whether the pre-charging process is completed by the output bus capacitor voltage or the pre-charging completion communication signal of the air compressor controller 180. For example, if it is detected that the bus voltage is equal to the power battery voltage, it indicates that the output bus capacitor pre-charging is completed, and the BOP device 150 and the air compressor controller 180 send a CAN (Controller Area Network) message for indicating that the pre-charging is completed, then the pre-charging is completed.

[0044] Further, the controller 140 controls the bus voltage of the output bus capacitor to change 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: Controlling the auxiliary pre-charging circuit 130 to remain turned on, so as to control the BOP device 150 to continue to work; By disconnecting the battery stack 200 from the power battery 300, the battery stack voltage 200 and the bus voltage of the output bus capacitor are controlled to increase to the open circuit voltage; After the single-cell consistency condition of the battery stack 200 is met, controlling the voltage of the battery stack 200 and the bus voltage to decrease from the open circuit voltage to the power battery voltage; By controlling the chopping operation of the boost DC / DC converter 110 , the voltage of the fuel cell stack 200 is controlled to decrease from the power battery voltage to the rated voltage, thereby completing the startup of the fuel cell.

[0045] Specifically, after the pre-charging is completed, the auxiliary pre-charging circuit 130 is controlled to be turned on so that the BOP device 150 can continue to work and continuously provide a stable reaction environment for the battery stack 200, for example, supplying oxygen and hydrogen to the battery stack 200, adjusting the temperature and moisture content, etc. Afterwards, the connection between the battery stack 200 and the power battery 300 is disconnected, the positive and negative electrodes of the battery stack 200 accumulate charges, and the voltage Vc1 of the battery stack 200 gradually increases until the power battery voltage Vbat. The charges of the positive and negative electrodes of the battery stack 200 continue to accumulate until the voltage Vc1 of the battery stack 200 reaches the open circuit voltage of the battery stack 200. A small amount of charge on the positive and negative electrodes of the battery stack 200 will be 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 follow the continued rise of the voltage Vc1 of the battery stack 200 and rise to near the open circuit voltage Voc. At this time, the voltage Vc1 of the stack 200 rises to the open circuit voltage Voc, and is briefly maintained near the open circuit voltage Voc. After ensuring that the stack 200 meets the consistency condition of the single cell of the stack 200, the bus voltage Vc2 is pulled down to the power battery voltage Vbat by controlling the discharge of the output bus capacitor. When the bus voltage Vc2 is detected to be equal to the power battery voltage Vbat in a continuous time period, the boost DC / DC converter 110 is controlled to perform chopping operation to increase the output current of the stack 200, so that the voltage Vc1 of the stack 200 is reduced from the open circuit voltage Voc to the rated voltage, so that the stack 200 smoothly transitions from the startup state to the BOOST operation mode, and the fuel cell system is smoothly started. After the fuel cell system is started, the voltage Vc1 of the stack 200 output by the stack 200 can be adjusted by controlling the duty cycle of the BOOST boost circuit 111 in the boost DC / DC converter 110.

[0046] 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 the preset threshold value, it can be indicated that the bus voltage Vc2 is approximately equal to the open circuit voltage Voc. The preset threshold value is a minimum value, which is used to characterize the degree of proximity between the bus voltage Vc2 and the open circuit voltage Voc of the battery stack 200. The preset threshold value can be set according to experience. For example, the preset threshold value can be 0.1V, 0.5V or 1V, etc., and the embodiment of the present invention is not limited to this.

[0047] It should be noted that the cell consistency condition of the stack 200 means that the performance of each single cell in the stack 200 remains consistent. The performance of each single cell may include: voltage, current, temperature, chemical reaction rate, moisture and reaction gas distribution, etc., which is not limited in the embodiment of the present invention.

[0048] Further, Figure 2 FIG. 1 is a partial schematic diagram of a fuel cell system startup circuit provided by an embodiment of the present invention. Figure 2As shown, the main pre-charging circuit 120 includes a main pre-charging branch 121 and a main positive contactor K1 connected in parallel, and the main pre-charging branch 121 includes a main pre-charging resistor R4 and a main pre-charging contactor K4 connected in series.

[0049] Specifically, in the default state, the main negative contactor K2, the main positive contactor K1 and the pre-charge contactor K4 are all in the disconnected state. After the controller 140 receives the standby command input by the user, it can control the main negative contactor K2 to close, and then control the pre-charge contactor K4 to close, and the current generated by the power battery 300 flows into the output bus capacitor to pre-charge the output bus capacitor. After the output bus capacitor is pre-charged, the main positive contactor K1 is controlled to close, and the pre-charge contactor K4 is controlled to disconnect. At this time, the bus voltage Vc2 corresponding to the output bus capacitor C2 can reach the power battery voltage Vbat.

[0050] Furthermore, if Figure 2 As shown, the auxiliary pre-charging circuit 130 includes an auxiliary pre-charging branch 131 and an auxiliary positive contactor K5 connected in parallel, and the auxiliary pre-charging branch 131 includes an auxiliary pre-charging resistor R5 and an auxiliary pre-charging contactor K6 connected in series.

[0051] Specifically, one end of the auxiliary pre-charging branch 131 and the auxiliary positive contactor K5 connected in parallel is connected to the BOP device 150, and the other end of the parallel connection is connected to the second positive electrode Uo+ of the power battery 300. The end of the auxiliary pre-charging resistor R5 that is not connected to the auxiliary pre-charging contactor K6 is connected to the BOP device 150, and the end of the auxiliary pre-charging contactor K6 that is not connected to the auxiliary pre-charging resistor R5 is connected to the second positive electrode Uo+ of the power battery 300. In the default state, the auxiliary positive contactor K5 and the auxiliary pre-charging contactor K6 are both in the disconnected state. After the controller 140 receives the standby command input by the user, it can control the main negative contactor K2 to close, and then control the auxiliary pre-charging contactor K6 to close. The current generated by the power battery 300 flows into the output bus capacitor while also flowing into the BOP device 150 to pre-charge the BOP device 150. After the pre-charging of the BOP device 150 is completed, the auxiliary positive contactor K5 is controlled to close, and the auxiliary pre-charging contactor K6 is controlled to open. At this time, the voltage of the BOP device 150 may reach the power battery voltage Vbat.

[0052] Furthermore, the boost DC / DC converter 110 includes a plurality of BOOST boost circuits 111 connected in parallel in an interlaced manner; each of the BOOST boost circuits 111 is connected to the controller 140; and the controller 140 is used for performing staggered phase control on each of the BOOST boost circuits 111 based on a PWM signal.

[0053] Specifically, the first end of each BOOST boost circuit 111 is connected to the first positive electrode Ui+ of the stack 200, the second end of each BOOST boost circuit 111 is connected to the first negative electrode Ui- of the stack 200, the second end of the output bus capacitor C2 and the first end of the main negative contactor K2, the system is non-isolated and shares a common negative electrode, the third end of each BOOST boost circuit 111 is connected to the first end of the output bus capacitor and the first end of the main pre-charging circuit 120, the second end of the main pre-charging circuit 120 is connected to the second positive electrode Uo+ of the power battery 300, and the second end of the main negative contactor K2 is connected to the second negative electrode Uo- of the power battery 300. The controller 140 can perform phase-shifting control on each BOOST boost circuit 111 according to the PWM control signal, and convert the voltage Vc1 of the 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 controls the voltage, current and power of the fuel cell system in a closed loop.

[0054] Optionally, the output end of the battery stack 200 is directly connected to the boost DC / DC converter 110 via a copper busbar.

[0055] Furthermore, the circuit structures of the BOOST boost circuits 111 are the same. Figure 3 is a schematic diagram of the structure of a BOOST boost circuit provided by an embodiment of the present invention, such as Figure 3 As shown, the BOOST boost circuit 111 includes: an inductor L1, a diode D1 and a MOS tube Q1, wherein: The first end of the inductor L1 serves as the first end of the BOOST boost circuit 111, the second end of the inductor L1 is connected to the anode of the diode D1 and the drain of the MOS tube Q1, the cathode of the diode D1 serves as the third end of the BOOST boost circuit 111, the source of the MOS tube Q1 serves as the third end of the BOOST boost circuit 111, and the gate of the MOS tube Q1 is used to receive the control signal input by the controller 140.

[0056] Further, Figure 4 is a circuit diagram of a fuel cell system startup circuit provided by an embodiment of the present invention, such as Figure 4 As shown, the fuel cell system starting circuit also includes a bus resistor R2, and the bus resistor R2 is connected in parallel to both ends of the output bus capacitor.

[0057] A discharge circuit 160 and an input support capacitor branch 170 may also be included between the stack 200 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 electrode Ui+ and the first negative electrode Ui- of the stack 200. The discharge circuit 160 can provide a safe release path for the residual energy output by the stack 200, and can prevent the stack 200 from accumulating too high a voltage in a non-working state, thereby protecting the stack 200 and the equipment connected to the stack 200 from damage. The input support capacitor branch 170 includes a first capacitor C1 and a first resistor R1 connected in parallel, and is connected in parallel between the first positive electrode Ui+ and the first negative electrode Ui- of the stack 200. The input support capacitor branch 170 is used to connect to the input of the boost DC / DC converter 110 and the output of the stack 200, reduce voltage and current pulsation impacts, play a filtering and buffering role, and ensure that the fuel cell system can be started and operated safely and reliably.

[0058] Furthermore, the controller 140 is also communicatively connected to the vehicle CAN network 230 , and 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 battery stack 200 voltage.

[0059] Specifically, Figure 5 is a connection diagram of a fuel cell system provided by an embodiment of the present invention, such as Figure 5 As shown, the fuel cell system includes the above-mentioned fuel cell system starting circuit, the stack 200, the BOP device 150, the fuel cell control unit 220 (Fuel cell Control Unit, FCU) and the fuel cell CAN network 210, and the fuel cell CAN network 210 is connected to the stack 200, the FCU, the BOP device 150, the air compressor controller 180 and the vehicle CAN network 230. The vehicle CAN network 230 is connected to the power battery 300. The controller 140 can obtain the power battery voltage through the fuel cell CAN network 210 and the vehicle CAN network 230, and sample and obtain the bus voltage, the stack 200 voltage and the input and output current. The fuel cell control unit 220 can adjust the working 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 the ejector through the fuel cell CAN network 210, control the gear of the cooling fan to control the speed, etc. The fuel cell control unit 220 can obtain information such as the voltage and current of a single cell 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 .

[0060] The fuel cell system startup circuit provided by the embodiment of the present invention independently controls the main pre-charging circuit and the auxiliary pre-charging circuit, and independently pre-charges and manages the power supply of the output bus capacitor and the BOP device. After the pre-charging is completed and the power battery voltage is lower than the open circuit voltage of the battery stack, the startup of the fuel cell system is completed by controlling 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. In the present invention, the boost DC / DC converter replaces the buck-boost topology, controls the bus voltage to dynamically change between the power battery voltage and the open circuit voltage, and the chopping operation of the boost DC / DC converter, so that the fuel cell system can be started smoothly, saving the use of a large number of electronic components required for the buck module in the buck-boost topology, thereby greatly reducing the equipment cost, reducing the equipment volume and weight, and the control is simpler and more reliable, and the efficiency is higher.

[0061] The embodiment of the present invention further provides a fuel cell system startup method, which is applied to any of the fuel cell system startup circuits described above. Figure 6 is one of the flow charts of the fuel cell system startup method provided by an embodiment of the present invention, such as Figure 6 As shown, the method includes the following steps 610 to 640.

[0062] 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 power supply management the BOP device; after the pre-charging is completed, the bus voltage of the output bus capacitor is the power battery voltage.

[0063] Step 620: When the pre-charging of the output bus capacitor and the BOP device is completed and the open circuit voltage of the battery stack is higher than the power battery voltage, the battery stack is disconnected from the power battery to control the battery stack voltage together with the bus voltage to increase to the open circuit voltage.

[0064] Step 630: After the battery stack single-cell consistency condition is met, close the main pre-charging contactor in the main pre-charging circuit, and pull the battery stack voltage and the bus voltage down to the power battery voltage through the main pre-charging resistor in the main pre-charging circuit.

[0065] Step 640, close the main positive contactor in the main pre-charging circuit, open the main pre-charging contactor, control the stack voltage to drop to the rated voltage by controlling the chopping operation of the boost DC / DC converter, and complete the startup of the fuel cell system.

[0066] Specifically, Figure 7 This is the second flow chart of the fuel cell startup method provided by the embodiment of the present invention. Figure 8FIG. 1 is a schematic diagram of voltage changes during the startup process of a fuel cell system provided by an embodiment of the present invention. Figure 7 and Figure 8 As shown, the power-on startup process of the fuel cell system includes the following steps S1 to S6.

[0067] S1, pre-charging stage: close the main negative contactor K2, the main pre-charging contactor K4 and the auxiliary pre-charging contactor K6, and independently pre-charge and power supply management the output bus capacitor and BOP equipment of the boost DC / DC converter. After the pre-charging is completed, the output bus capacitor and BOP equipment are pre-charged to the power battery voltage. After that, close the main positive contactor K1 and the auxiliary positive contactor K5, and disconnect the main pre-charging contactor K4 and the auxiliary pre-charging contactor K6, so that the BOP equipment can continue to work and provide a stable reaction environment for the battery stack.

[0068] S2. After the output bus capacitor and the BOP device are pre-charged, the power battery voltage is obtained, and it is determined whether the power battery voltage Vbat is higher than the open circuit voltage Voc of the battery stack.

[0069] S3. If the open circuit voltage Voc is lower than the power battery voltage Vbat, the boost DC / DC converter is controlled to operate, output power to the power system, and raise the battery stack voltage to the rated voltage.

[0070] S4, battery stack start-up phase: If the open circuit voltage Voc is higher than the power battery voltage Vbat, the controller can control the connection between the battery stack and the power battery to be disconnected, and the battery stack enters the start-up phase. After the battery stack enters the start-up phase, as the electrochemical reaction in the battery stack proceeds, the positive and negative electrodes of the battery stack continue to accumulate charge, and the battery stack voltage Vc1 of the battery stack gradually increases until it reaches the power battery voltage Vbat. In this process, due to the reverse blocking of the diode D1 in the boost DC / DC converter and the main pre-charge circuit is in the disconnected state, the output bus capacitor C2 can only be slowly discharged through the bus resistor R2, and the bus voltage Vc2 is approximately maintained near the power battery voltage Vbat of the power battery in a short period of time.

[0071] S5, the stage of rising open circuit voltage: as the positive and negative charges of the battery stack continue to accumulate, the battery stack voltage Vc1 continues to rise. When the battery stack voltage Vc1 is equal to the bus voltage Vc2, a small amount of charge in the battery stack will be output to the output bus capacitor for charging. Since the output bus capacitor C2 has a small capacitance and the main pre-charge circuit is in the disconnected 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 disconnected state, and the battery stack voltage Vc1 will not be embedded in the power battery voltage Vbat by the large-capacity power battery, causing the battery stack "single low" fault and "reverse polarity" fault. The battery stack voltage Vc1 can continue to rise to near the open circuit voltage Voc and maintain it for a short time.

[0072] S6, BOOST loading stage: After each single cell in the stack meets the single cell consistency condition of the stack, the stack voltage Vc1 can be controlled to load quickly. Specifically, since the bus voltage Vc2 rises to near the open circuit voltage Voc, the bus voltage Vc2 is already higher than the power battery voltage Vbat. At this time, the main pre-charging contactor K4 can be controlled to close, and the output bus capacitor C2 can be discharged through the main pre-charging branch. Under the action of the pre-charging resistor R4, the discharge process will not generate surge current, and the bus voltage Vc2 will be pulled down to near the power battery voltage Vbat again. After that, the bus voltage Vc2 is continuously monitored. When it is detected that the bus voltage Vc2 is equal to the power battery voltage Vbat within a continuous time period, the main positive contactor K1 is controlled to close, and the main pre-charging contactor K4 is controlled to disconnect. At this time, the controller can control the boost DC / DC converter to chop and operate to reduce the stack voltage until it is reduced to the rated voltage, completing the startup of the fuel cell system.

[0073] It should be noted that a "single low" fault in a battery stack refers to a situation where the voltage of a single cell or multiple single cells in the battery stack is lower than the normal operating voltage. A "single low" fault can cause the performance of surrounding batteries to decline, and even affect the performance and life of the entire battery stack. A "reverse polarity" fault refers to a situation where the voltage of a single cell is lower than zero volts during the operation of the battery stack, that is, the polarity of the anode and cathode of the single cell is reversed. "Reverse polarity" will not only cause severe corrosion of the anode catalyst, but may also cause corrosion of the metal bipolar plate, thereby accelerating the attenuation of battery performance and even causing irreversible damage to the battery stack.

[0074] Furthermore, controlling the voltage of the battery stack to decrease to a rated voltage by controlling the chopper operation of the boost DC / DC converter includes: By controlling the duty cycle of the boost DC / DC converter, the output current of the battery stack is controlled to increase so as to reduce the battery stack voltage until the battery stack voltage is reduced to the rated voltage.

[0075] Specifically, in the above step S6, a control signal can be input to the gate of the MOS tube Q1 in the BOOST boost circuit to control the BOOST boost circuit to operate in a chopper, that is, to control the duty cycle of the BOOST boost circuit, thereby controlling the output current of the stack to increase. Based on the external characteristics of the stack output, the increase in output current will reduce the stack output voltage Vc1 until it is reduced to the rated voltage, completing the startup of the fuel cell.

[0076] It should be noted that the control signal can be a PWM (Pulse Width Modulation) signal. By adjusting the duty cycle of the control signal, the on-off frequency and duty cycle of the MOS tube Q1 can be adjusted, thereby controlling the output load and increasing the current output by the battery stack. When the MOS tube Q1 is turned on, the output current of the battery stack is stored in the inductor L1. When the MOS tube Q1 is turned off, the inductor L1 releases energy, and the current provided flows to the power battery through the diode D1 and the main positive contactor K1.

[0077] Further, disconnecting the battery stack from the power battery includes: Disconnect the main positive contactor and the main pre-charge branch.

[0078] Specifically, in the above step S4, the controller can control the main positive contactor K1 to be disconnected. At this time, the main pre-charging circuit is in a disconnected state, based on which the connection between the battery stack and the power battery is disconnected.

[0079] The fuel cell system startup method provided by the embodiment of the present invention independently controls the main pre-charging circuit and the auxiliary pre-charging circuit, and pre-charges the output bus capacitor and the BOP device respectively. When the power battery voltage is lower than the open circuit voltage of the fuel cell, the connection between the battery stack and the power battery is disconnected to control the battery stack voltage together with the bus voltage to increase to the open circuit voltage. After the battery stack single cell consistency condition is met, the main pre-charging contactor is closed, and the battery stack voltage and the bus voltage are pulled down from the open circuit voltage to the power battery voltage through the main pre-charging resistor, and then the main positive contactor is closed, the main pre-charging contactor is disconnected, and the boost DC / DC converter is controlled to chop and run, and the battery stack voltage is further pulled down to the rated voltage to complete the startup of the fuel cell system. When the open circuit voltage of the fuel cell is higher than the power battery voltage of the power battery, the fuel cell can be smoothly started and transitioned to the rated working state through simple timing control in the embodiment of the present invention. Compared with the buck-boost topology, the use of general half-power devices is saved, thereby greatly reducing the equipment cost, reducing the equipment volume and weight, and the control is simple and reliable, and the efficiency is improved.

[0080] Fig. 9 is a schematic diagram of the logical topology of the controller provided by an embodiment of the present invention, such as Fig. 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, wherein 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; The CAN communication module 940 is connected to the vehicle CAN network, and the CAN communication module 940 is used to obtain the power battery voltage; The ADC sampling module 920 is used to collect the bus voltage and the stack voltage corresponding to the output bus capacitance; The PWM module 960 is used to generate a control signal, and the control signal is used to control the chopping operation of the boost DC / DC converter; When the processor 910 executes the computer program, the method for starting the fuel cell system as described in any one of the above items is implemented. When the processor 910 executes the computer program, the method for starting the fuel cell system as described in any one of the above items is implemented, and the method includes: 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 power supply management the BOP equipment; 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 battery stack is higher than the voltage of the power battery, disconnecting the battery stack from the power battery to control the battery stack voltage together with the bus voltage to increase to the open circuit voltage; After the battery stack single-cell consistency condition is met, the main pre-charging contactor in the main pre-charging circuit is closed, and the battery stack voltage and the bus voltage are pulled down to the power battery voltage through the main pre-charging resistor in the main pre-charging circuit; The main positive contactor in the main pre-charging circuit is closed, and the main pre-charging contactor is opened. By controlling the chopping operation of the boost DC / DC converter, the stack voltage is controlled to drop to the rated voltage, thereby completing the startup of the fuel cell system.

[0081] The communication interface 950 in the controller can be a digital IO (Input / Output) interface for transmitting digital signals. The above-mentioned memory 930 can include a RAM random access memory (RAM, Random Access Memory) and a FLASH memory. The logic instructions of the memory 930 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods of various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory, disk or optical disk and other media that can store program codes.

[0082] On the other hand, the present invention further provides a computer program product, the computer program product includes a computer program, the computer program can be stored in a non-transitory computer-readable storage medium, when the computer program is executed by a processor, the computer can execute the fuel cell system startup method provided by the above methods, the method includes: 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 power supply management the BOP equipment; 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 battery stack is higher than the voltage of the power battery, disconnecting the battery stack from the power battery to control the battery stack voltage together with the bus voltage to increase to the open circuit voltage; After the battery stack single-cell consistency condition is met, the main pre-charging contactor in the main pre-charging circuit is closed, and the battery stack voltage and the bus voltage are pulled down to the power battery voltage through the main pre-charging resistor in the main pre-charging circuit; The main positive contactor in the main pre-charging circuit is closed, and the main pre-charging contactor is opened. By controlling the chopping operation of the boost DC / DC converter, the stack voltage is controlled to drop to the rated voltage, thereby completing the startup of the fuel cell system.

[0083] In another aspect, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the method for starting a fuel cell system provided by the above methods is implemented, and the method comprises: 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 power supply management the BOP equipment; 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 battery stack is higher than the voltage of the power battery, disconnecting the battery stack from the power battery to control the battery stack voltage together with the bus voltage to increase to the open circuit voltage; After the battery stack single-cell consistency condition is met, the main pre-charging contactor in the main pre-charging circuit is closed, and the battery stack voltage and the bus voltage are pulled down to the power battery voltage through the main pre-charging resistor in the main pre-charging circuit; The main positive contactor in the main pre-charging circuit is closed, and the main pre-charging contactor is opened. By controlling the chopping operation of the boost DC / DC converter, the stack voltage is controlled to drop to the rated voltage, thereby completing the startup of the fuel cell system.

[0084] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, i.e., they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Those of ordinary skill in the art may understand and implement it without creative effort.

[0085] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as FLASH, ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods of each embodiment or some parts of the embodiment.

[0086] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fuel cell system starting circuit, characterized in that: include: Controller, boost DC / DC converter, output bus capacitor, main pre-charge circuit and auxiliary pre-charge circuit, where: The input end of the boost DC / DC converter is connected to the battery stack, and the output end of the boost DC / DC converter is connected to the power battery through the output bus capacitor and the main pre-charging circuit; A BOP device as an auxiliary device of the battery stack is connected to the power battery through 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 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 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 after the pre-charging is completed and the open circuit voltage of the battery stack is higher than the power battery voltage, to complete the startup of the fuel cell system.

2. The fuel cell system startup circuit according to claim 1, characterized in that: The controller controls the bus voltage of the output bus capacitor to change between the power battery voltage and the open circuit voltage, and the chopper operation of the boost DC / DC converter to complete the startup of the fuel cell system, including: Controlling the auxiliary pre-charging circuit to remain turned on, so as to control the BOP device to continue to work; By disconnecting the battery stack from the power battery, controlling the battery stack voltage and the bus voltage of the output bus capacitor to increase to the open circuit voltage; After the battery stack single cell consistency condition is met, controlling the battery stack voltage and the bus voltage to decrease from the open circuit voltage to the power battery voltage; The startup of the fuel cell is completed by controlling the chopper operation of the boost DC / DC converter to control the voltage of the fuel cell stack to decrease from the power battery voltage to the rated voltage.

3. The fuel cell system startup circuit according to claim 1, characterized in that: The main pre-charging circuit includes a main pre-charging branch and a main positive contactor connected in parallel, and the main pre-charging branch includes a main pre-charging resistor and a main pre-charging contactor connected in series.

4. The fuel cell system startup circuit according to claim 1, characterized in that: The auxiliary pre-charging circuit includes an auxiliary pre-charging branch and an auxiliary positive contactor connected in parallel, and the auxiliary pre-charging branch includes an auxiliary pre-charging resistor and an auxiliary pre-charging contactor connected in series.

5. The fuel cell system startup circuit according to claim 1, characterized in that: The boost DC / DC converter comprises a plurality of BOOST boost circuits connected in parallel in an interlaced manner; each of the BOOST boost circuits is connected to the controller; and the controller is used for performing staggered phase control on each of the BOOST boost circuits based on a PWM signal.

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

7. A fuel cell system startup method, characterized in that: Applied to the fuel cell system startup circuit according to any one of claims 1 to 6, the method comprising: 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 power supply management the BOP equipment; 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 battery stack is higher than the voltage of the power battery, disconnecting the battery stack from the power battery to control the battery stack voltage together with the bus voltage to increase to the open circuit voltage; After the battery stack single-cell consistency condition is met, the main pre-charging contactor in the main pre-charging circuit is closed, and the battery stack voltage and the bus voltage are pulled down to the power battery voltage through the main pre-charging resistor in the main pre-charging circuit; The main positive contactor in the main pre-charging circuit is closed, and the main pre-charging contactor is opened. By controlling the chopping operation of the boost DC / DC converter, the stack voltage is controlled to drop to the rated voltage, thereby completing the startup of the fuel cell system.

8. The fuel cell system startup method according to claim 7, characterized in that: The step of controlling the voltage of the battery stack to decrease to a rated voltage by controlling the chopper operation of the boost DC / DC converter comprises: By controlling the duty cycle of the boost DC / DC converter, the output current of the battery stack is controlled to increase so as to reduce the battery stack voltage until the battery stack voltage is reduced to the rated voltage.

9. The fuel cell system startup method according to claim 7, characterized in that: The disconnecting the battery stack from the power battery comprises: Disconnect the main positive contactor and the main pre-charge branch.

10. 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 and 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 CAN network, and the CAN communication module is used to obtain the power battery voltage; The ADC sampling module is used to collect the bus voltage and the stack voltage corresponding to the output bus capacitance; The PWM module is used to generate a control signal, and the control signal is used to control the chopping operation of the boost DC / DC converter; When the processor executes the computer program, the fuel cell system startup method as described in any one of claims 7 to 9 is implemented.

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