A multi-stack parallel controllable fuel cell system, a closed stack control method, and a vehicle

Abstract

The application provides a kind of multi-stack parallel controllable fuel cell system, closed stack control method and vehicle, belongs to fuel cell technical field.The system includes stack module, high-voltage power module, single switch module, air supply module, hydrogen supply module and thermal management module, and the stack module includes a plurality of electric piles in parallel, the positive terminal of each electric pile is connected with the positive terminal of high-voltage power module and forms electrical circuit, and the single switch module includes single switch unit configured for each electric pile, which includes a relay switch and a unidirectional diode arranged on the electrical circuit related to the positive terminal of the electric pile;The system further includes a first solenoid valve module for controlling the air supply module to independently provide air to the plurality of electric piles, a second solenoid valve module for controlling the hydrogen supply module to independently provide hydrogen to the plurality of electric piles, and a third solenoid valve module for controlling the thermal management module to independently provide coolant to the plurality of electric piles.The application can improve the operating life of the fuel cell system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fuel cell, in particular to a multi-stack parallel controllable fuel cell system, a stack closing control method and a vehicle. BACKGROUND

[0002] In the prior art, most fuel cells adopt a multi-stack parallel mode to achieve high-power output, by evenly distributing the vehicle demand power to each stack, and ensuring the uniformity of water-hydrogen-air medium distribution in the stack. However, due to the demand for small power output and idling during vehicle use, if the smaller vehicle demand power is evenly distributed to each stack, it will cause each single body in the stack to be at a high potential, thereby affecting the operating life of the stack. SUMMARY

[0003] The main purpose of the present application is to provide a multi-stack parallel controllable fuel cell system, a stack closing control method and a vehicle to solve one or more technical problems existing in the prior art, and at least provide a beneficial choice or create conditions.

[0004] To achieve the above-mentioned purpose, one aspect of the present application provides a multi-stack parallel controllable fuel cell system, comprising a stack module, a high-voltage power module, a single switch module, an air supply module, a first electromagnetic valve module, a hydrogen supply module, a second electromagnetic valve module, a thermal management module and a third electromagnetic valve module;

[0005] The stack module comprises a plurality of stacks connected in parallel, the positive electrode end of each stack is connected to the positive electrode end of the high-voltage power module and forms an electrical circuit, and the negative electrode end of each stack is connected to the negative electrode end of the high-voltage power module.

[0006] The single switch module comprises a single switch unit configured for each stack, the single switch unit comprises a relay switch and a unidirectional diode, the relay switch and the unidirectional diode are arranged on the electrical circuit related to the positive electrode end of the stack, and the positive electrode end of the high-voltage power module is connected to the positive electrode end of the stack through the relay switch and the unidirectional diode in sequence.

[0007] The first electromagnetic valve module comprises a first electromagnetic valve group configured for each stack, and the first electromagnetic valve group is used to control the air supply module to provide air to the stack.

[0008] The second electromagnetic valve module comprises a second electromagnetic valve group configured for each stack, and the second electromagnetic valve group is used to control the hydrogen supply module to provide hydrogen to the stack.

[0009] The third electromagnetic valve module includes a third electromagnetic valve group configured for each of the stacks, and the third electromagnetic valve group is used to control the thermal management module to provide coolant to the stacks.

[0010] Further, the first electromagnetic valve group configured for each of the stacks includes a first input electromagnetic valve and a first output electromagnetic valve, and the cathode inlet of the stack is connected with the air supply module through the first input electromagnetic valve, and the cathode outlet of the stack is connected with the air supply module through the first output electromagnetic valve.

[0011] Further, the second electromagnetic valve group configured for each of the stacks includes a second input electromagnetic valve and a second output electromagnetic valve, and the anode inlet of the stack is connected with the hydrogen supply module through the second input electromagnetic valve, and the anode outlet of the stack is connected with the hydrogen supply module through the second output electromagnetic valve.

[0012] Further, the third electromagnetic valve group configured for each of the stacks includes a third input electromagnetic valve and a third output electromagnetic valve, and the coolant inlet of the stack is connected with the thermal management module through the third input electromagnetic valve, and the coolant outlet of the stack is connected with the thermal management module through the third output electromagnetic valve.

[0013] To achieve the above object, another aspect of the present application provides a closed stack control method applied to the above-mentioned multi-stack parallel controllable fuel cell system, and the closed stack control method includes:

[0014] When the multiple stacks in electrical parallel are in a normal working state, a current vehicle demand power is obtained;

[0015] According to the current vehicle demand power, a number of stacks currently required to be closed is determined;

[0016] When the number of stacks is greater than zero, historical running parameter values of the multiple stacks are obtained;

[0017] According to the number of stacks and the historical running parameter values of the multiple stacks, all target stacks currently required to be closed are screened out from the multiple stacks, and the all target stacks are controlled to perform a closing operation.

[0018] Further, each of the stacks in the normal working state includes that a relay switch configured for the stack is in a closed state, a first electromagnetic valve group configured for the stack is in an open state at a preset opening degree, and a second electromagnetic valve group and a third electromagnetic valve group configured for the stack are in a fully open state.

[0019] Further, the control of the all target stacks to perform the closing operation includes:

[0020] For each of the target stacks, control a relay switch configured for the target stack to be in an off state;

[0021] Control a first electromagnetic valve group configured for the target stack to be in a fully open state, and then control the air supply module to perform air blowing on the target stack for a first preset time length;

[0022] Control a first electromagnetic valve group configured for the target stack to be in a fully closed state, and then control the target stack to perform oxygen consumption discharge for a second preset time length;

[0023] Control a second electromagnetic valve group configured for the target stack to be in a fully closed state, and then control a third electromagnetic valve group configured for the target stack to be in a fully closed state after a third preset time length.

[0024] Further, the historical running parameter values of the plurality of stacks include historical working time lengths of the plurality of stacks; and the filtering of the target stacks from the plurality of stacks includes:

[0025] Filtering all stacks with the number of stacks matched from the plurality of stacks with the largest historical working time length, and taking the filtered all stacks as the target stacks currently required to be closed.

[0026] Further, the historical running parameter values of the plurality of stacks include average single cell voltages of the plurality of stacks; and the filtering of the target stacks from the plurality of stacks includes:

[0027] Filtering all stacks with the number of stacks matched from the plurality of stacks with the smallest average single cell voltage, and taking the filtered all stacks as the target stacks currently required to be closed.

[0028] To achieve the above-mentioned purpose, another aspect of the present application provides a vehicle comprising the above-mentioned multi-stack parallel controllable fuel cell system.

[0029] The present application has at least the following beneficial effects: in the case of multiple stacks in electrical parallel connection, by configuring a single switch unit for each stack to control the communication relationship between the stack and the high-voltage power module, by configuring a first electromagnetic valve group for each stack to control the communication relationship between the stack and the air supply module, by configuring a second electromagnetic valve group for each stack to control the communication relationship between the stack and the hydrogen supply module, and by configuring a third electromagnetic valve group for each stack to control the communication relationship between the stack and the thermal management module, the multiple stacks can work simultaneously to achieve high-power output, and in the case of relatively small power demand, some of the stacks can work simultaneously to avoid the fuel cell system being in a high potential state to cause carbon corrosion and other degradation phenomena, so as to ensure that the fuel cell system has a relatively large power range output, and to improve the operating life of the fuel cell system. By determining the target stack to be closed according to the historical operating parameter values of the multiple stacks in the case of relatively small power demand and performing a closing operation on the target stack, the operating life of the multiple stacks can be balanced. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a structural composition schematic diagram of a multiple-stack parallel controllable fuel cell system provided by an embodiment of the present application;

[0031] Figure 2 is a structural composition schematic diagram of a combined stack module, a high-voltage power module, and a single switch module provided by an embodiment of the present application;

[0032] Figure 3 is a structural composition schematic diagram of a combined stack module, an air supply module, and a first electromagnetic valve module provided by an embodiment of the present application;

[0033] Figure 4 is a structural composition schematic diagram of a combined stack module, a hydrogen supply module, and a second electromagnetic valve module provided by an embodiment of the present application;

[0034] Figure 5 is a structural composition schematic diagram of a combined stack module, a thermal management module, and a third electromagnetic valve module provided by an embodiment of the present application;

[0035] Figure 6 is a flow schematic diagram of a stack closing control method provided by an embodiment of the present application. DETAILED DESCRIPTION

[0036] In order to make the purposes, technical solutions, and advantages of the present application clearer, further, the present application is described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not intended to limit the present application. When the following description refers to the accompanying drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with embodiments of the present application. They are only examples of systems and methods consistent with some aspects of the embodiments of the present application as detailed in the appended claims.

[0037] It can be understood that the terms "first", "second", and the like used in the present application can be used herein to describe various concepts, but unless otherwise specified, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another. For example, without departing from the scope of the embodiments of the present application, the first information can also be referred to as the second information, and similarly, the second information can also be referred to as the first information.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used herein are only for the purpose of describing the embodiments of the present application and are not intended to limit the present application.

[0039] In the prior art, with the gradual emergence of high-power scenarios for vehicles, the traditional single-stack fuel cell can only achieve high-power output by increasing the number of monomers or the active area of monomers, but this will bring other application drawbacks, such as uneven distribution of current through the monomers, uneven distribution of reactants required by the monomers, etc. In order to overcome the application drawbacks existing in the single-stack fuel cell itself, some people have proposed using a multi-stack parallel fuel cell to achieve high-power output, by evenly distributing the entire vehicle demand power to each stack, and ensuring the uniformity of the water-hydrogen-air medium distribution of the stack. However, due to the demand for small power output and idling during vehicle use, if the smaller entire vehicle demand power is evenly distributed to each stack, this will cause each monomer inside the stack to be at a high potential, thereby affecting the operating life of the stack.

[0040] Therefore, the embodiment of the present application provides a multi-stack parallel controllable fuel cell system, a closed stack control method and a vehicle. In the case that multiple stacks are in an electrical parallel state, a single switch unit is configured for each stack to control the communication relationship between the stack and a high-voltage power module, a first electromagnetic valve group is configured for each stack to control the communication relationship between the stack and an air supply module, a second electromagnetic valve group is configured for each stack to control the communication relationship between the stack and a hydrogen supply module, and a third electromagnetic valve group is configured for each stack to control the communication relationship between the stack and a thermal management module. Therefore, the multiple stacks can work simultaneously to achieve large power output, and part of the stacks can work simultaneously to avoid the fuel cell system being in a high potential state to cause carbon corrosion and other degradation phenomena in the case that the power demand is relatively small. Therefore, the fuel cell system can have a large power range output and the operation life of the fuel cell system can be improved. In the case that the power demand is relatively small, the historical operation parameter values of the multiple stacks are used to determine the target stack to be closed and perform a closing operation on the target stack. Therefore, the operation life of the multiple stacks can be balanced.

[0041] Figure 1 is a structural composition schematic diagram of a multi-stack parallel controllable fuel cell system provided by the embodiment of the present application. The system mainly includes a stack module, a high-voltage power module, an air supply module, a hydrogen supply module, a thermal management module, a single switch module, a first electromagnetic valve module, a second electromagnetic valve module and a third electromagnetic valve module. The high-voltage power module is connected with the stack module through the single switch module, the air supply module is connected with the stack module through the first electromagnetic valve module, the hydrogen supply module is connected with the stack module through the second electromagnetic valve module, and the thermal management module is connected with the stack module through the third electromagnetic valve module.

[0042] Specifically, referring to Figure 2 The stack module includes multiple stacks in electrical parallel state. The positive electrode ends of the stacks 101_1 to 101_N are connected together, the negative electrode ends of the stacks 101_1 to 101_N are connected together, the positive electrode end of each stack 101_i is connected with the positive electrode end of the high-voltage power module and forms an electrical circuit, and the negative electrode end of each stack 101_i is connected with the negative electrode end of the high-voltage power module, i=1, 2,..., N, and N is the number of multiple stacks.

[0043] Specifically, referring to Figure 2As shown, the single switch module includes a single switch unit configured for each stack 101_i, which includes a relay switch Pi and a unidirectional diode Di, which are arranged on an electrical circuit related to the positive terminal of the stack 101_i, and the positive terminal of the high-voltage power module is connected to the positive terminal of the stack 101_i through the relay switch Pi and the unidirectional diode Di in turn, and the relay switch Pi can be used to control the high-voltage power module to provide power output for the stack 101_i.

[0044] By arranging the unidirectional diode Di on the electrical circuit formed between the positive terminal of the stack 101_i and the positive terminal of the high-voltage power module, the current flowing when the high-voltage power module is power converted can be ensured to be unidirectional, avoiding current mutual interconnection with other stacks to cause adverse conditions such as stack burning.

[0045] In some embodiments, the high-voltage power module includes a DC-DC converter, and for each stack 101_i and the single switch unit configured therefor, the positive terminal of the DC-DC converter is connected to the positive terminal of the stack 101_i through the single switch unit, and the negative terminal of the DC-DC converter is connected to the negative terminal of the stack 101_i, and the DC-DC converter is connected to an external vehicle voltage platform, and is used to convert the direct current provided by the vehicle voltage platform and supply it to the stack 101_i.

[0046] It should be noted that the present application sets multiple stacks in an electrical parallel working mode, and the precondition is that when the specifications of each stack 101_i are the same, it is determined that N x M x U0≥ U B This expression is true, N is the number of multiple stacks, M is the number of all single cells contained in the stack, U0is the maximum instantaneous output voltage of the stack single cell and is generally about 1V, and U B The reference voltage level of the vehicle voltage platform is, for example, the reference voltage level of the vehicle voltage platform designed for common commercial vehicles is 600V.

[0047] In addition, the selection of the DC-DC converter is described as follows: when M B / U0this expression is true, that is, the stack is designed according to the basic requirements, and it is determined that the DC-DC converter adopts a step-up DC-DC converter; when M B / U0this expression is true, that is, the stack is designed according to special requirements, and it is determined that the DC-DC converter adopts a step-up and step-down DC-DC converter, and when the working voltage of the stack is low, the DC-DC converter operates in step-up mode, and when the working voltage of the stack exceeds the reference voltage level of the vehicle voltage platform, the DC-DC converter operates in step-down mode.

[0048] Specifically, the first electromagnetic valve module includes a first electromagnetic valve group configured for each stack 101_i, which is used to control the air supply module to provide air to the stack 101_i.

[0049] In some embodiments, referring to Figure 3 As shown, the first electromagnetic valve group configured for each stack 101_i includes a first input electromagnetic valve 111_i and a first output electromagnetic valve 112_i, and the cathode inlet of the stack 101_i is connected to the air supply module through the first input electromagnetic valve 111_i, and the cathode outlet of the stack 101_i is connected to the air supply module through the first output electromagnetic valve 112_i. By arranging the first input electromagnetic valve 111_i at the cathode inlet of the stack 101_i and the first output electromagnetic valve 112_i at the cathode outlet of the stack 101_i, it is beneficial to more effectively cut off the air supply process of the stack 101_i, and ensure that no air enters when the stack 101_i is closed, thereby avoiding changes such as oxidation and deactivation of the catalyst inside the stack 101_i.

[0050] In some embodiments, referring to Figure 3 As shown, the air supply module includes an air compressor 121, a humidifier 122 and an expander 123, and for the first input electromagnetic valve 111_i and the first output electromagnetic valve 112_i configured for each stack 101_i, the inlet of the air compressor 121 is connected to the atmospheric environment, the outlet of the air compressor 121 is connected to the first inlet of the humidifier 122, and the first outlet of the humidifier 122 is connected to the cathode inlet of the stack 101_i through the first input electromagnetic valve 111_i, so that the air in the atmospheric environment is transported to the stack 101_i for electrochemical reaction after being processed by the air compressor 121 and the humidifier 122 in turn through the first input electromagnetic valve 111_i; the cathode outlet of the stack 101_i is connected to the second inlet of the humidifier 122 through the first output electromagnetic valve 112_i, the second outlet of the humidifier 122 is connected to the inlet of the expander 123, and the outlet of the expander 123 is connected to the atmospheric environment, and the expander 123 rotates coaxially with the motor of the air compressor 121, so that the humidifier 122 can mix and exchange the excess air discharged by the stack 101_i with the air transported by the air compressor 121, and then the expander 123 can recover the energy of the gas discharged by the humidifier 122 and reduce the power consumption of the air compressor 121.

[0051] Specifically, the second electromagnetic valve module includes a second electromagnetic valve group configured for each stack 101_i, which is used to control the hydrogen supply module to provide hydrogen to the stack 101_i.

[0052] In some embodiments, referring to Figure 4 As shown, the second electromagnetic valve group configured for each stack 101_i includes a second input electromagnetic valve 131_i and a second output electromagnetic valve 132_i, the anode inlet of the stack 101_i is connected with the hydrogen supply module through the second input electromagnetic valve 131_i, and the anode outlet of the stack 101_i is connected with the hydrogen supply module through the second output electromagnetic valve 132_i. By arranging the second input electromagnetic valve 131_i at the anode inlet of the stack 101_i and the second input electromagnetic valve 131_i at the anode outlet of the stack 101_i, more effective shutoff control of the hydrogen supply process of the stack 101_i is facilitated, and it is ensured that no hydrogen, nitrogen and moisture enters when the stack 101_i is closed.

[0053] In some embodiments, referring to Figure 4 As shown, the hydrogen supply module includes a hydrogen injection valve 141, a hydrogen inlet pressure stabilizing cavity 142, a gas-water separator 143, a hydrogen and water discharge valve 144, and an ejector 145_i and an eductor 146_i configured for each stack 101_i. For the second input electromagnetic valve 131_i and the second output electromagnetic valve 132_i configured for each stack 101_i, the external hydrogen supply device is connected with the inlet of the hydrogen inlet pressure stabilizing cavity 142 through the hydrogen injection valve 141, the outlet of the hydrogen inlet pressure stabilizing cavity 142 is connected with the inlet of the ejector 145_i, the outlet of the ejector 145_i is connected with the first inlet of the eductor 146_i, and the outlet of the eductor 146_i is connected with the anode inlet of the stack 101_i through the second input electromagnetic valve 131_i, so that the hydrogen in the hydrogen supply device is transported to the stack 101_i for electrochemical reaction through the second input electromagnetic valve 131_i after being processed in sequence through the hydrogen inlet pressure stabilizing cavity 142, the ejector 145_i and the eductor 146_i; the anode outlet of the stack 101_i is connected with the inlet of the gas-water separator 143 through the second output electromagnetic valve 132_i, the first outlet of the gas-water separator 143 is connected with the second inlet of the eductor 146_i, and the second outlet of the gas-water separator 143 is connected with the atmosphere through the hydrogen and water discharge valve 144, so that the gas-water separator 143 can separate the hydrogen discharged by the stack 101_i into liquid water and gas, and then transport the separated hydrogen to the stack 101_i through the eductor 146_i for recycling.

[0054] Specifically, the third electromagnetic valve module includes a third electromagnetic valve group configured for each stack 101_i, which is used to control the heat management module to provide cooling liquid to the stack 101_i.

[0055] In some embodiments, referring to Figure 5As shown, the third electromagnetic valve group configured for each stack 101_i includes a third input electromagnetic valve 151_i and a third output electromagnetic valve 152_i, the cooling liquid inlet of the stack 101_i is connected with the heat management module through the third input electromagnetic valve 151_i, and the cooling liquid outlet of the stack 101_i is connected with the heat management module through the third output electromagnetic valve 152_i. By arranging the third input electromagnetic valve 151_i at the cooling liquid inlet of the stack 101_i and the third output electromagnetic valve 152_i at the cooling liquid outlet of the stack 101_i, more effective cut-off control can be achieved for the cooling liquid supply process of the stack 101_i, and it is ensured that no cooling liquid enters when the stack 101_i is closed.

[0056] In some embodiments, referring to Figure 5 As shown, the heat management module includes an expansion water tank 161, an electric water pump 162, an electronic thermostat 163, a deionizer 164 and a radiator 165, a fan is arranged on the radiator 165 to improve the heat dissipation efficiency, and for the third input electromagnetic valve 151_i and the third output electromagnetic valve 152_i configured for each stack 101_i, the outlet of the expansion water tank 161 is connected with the inlet of the electric water pump 162, the outlet of the electric water pump 162 is connected with the cooling liquid inlet of the stack 101_i through the third input electromagnetic valve 151_i, the cooling liquid outlet of the stack 101_i is connected with the inlet of the electronic thermostat 163 through the third output electromagnetic valve 152_i, the first outlet of the electronic thermostat 163 is connected with the inlet of the deionizer 164, the outlet of the deionizer 164 is connected with the inlet of the electric water pump 162, the second outlet of the electronic thermostat 163 is connected with the inlet of the radiator 165, and the outlet of the radiator 165 is connected with the inlet of the electric water pump 162.

[0057] The multi-stack parallel controllable fuel cell system provided by the embodiments of the present application can make multiple stacks work simultaneously to achieve large power output by configuring a single switch unit for each stack to control the communication relationship between the stack and the high-voltage power module, configuring a first electromagnetic valve group for each stack to control the communication relationship between the stack and the air supply module, configuring a second electromagnetic valve group for each stack to control the communication relationship between the stack and the hydrogen supply module, and configuring a third electromagnetic valve group for each stack to control the communication relationship between the stack and the heat management module, and can make part of the stacks work simultaneously to avoid the fuel cell system being in a high potential state to cause carbon corrosion and other degradation phenomena when the power demand is relatively small, so that the fuel cell system can have a relatively large power range output and the operating life of the fuel cell system can be improved.

[0058] Figure 6is an optional flowchart of a stack closing control method provided by the embodiments of the present application, mainly applied to the above-mentioned multiple-stack parallel controllable fuel cell system, Figure 6 The method in the above-mentioned embodiment can but is not limited to comprising steps S201 to S204:

[0059] Step S201, obtaining the current vehicle demand power when the multiple stacks in electrical parallel are in normal working states;

[0060] Step S202, determining the number of stacks to be closed according to the current vehicle demand power;

[0061] Step S203, obtaining the historical operating parameter values of the multiple stacks when the number of stacks to be closed is greater than zero;

[0062] Step S204, screening all target stacks to be closed from the multiple stacks according to the number of stacks to be closed and the historical operating parameter values of the multiple stacks, and then controlling all the target stacks to perform the closing operation.

[0063] In step S201 of some embodiments, each stack in the normal working state comprises: the relay switch configured for the stack is in the closed state, the first electromagnetic valve group configured for the stack is in the open state at the preset opening degree, and the second electromagnetic valve group and the third electromagnetic valve group configured for the stack are in the fully open state; wherein the preset opening degree of the first electromagnetic valve group is preferably set to 80%, which can constrain the air supply module to provide appropriate flow of air to the stack, avoid accelerating the aging of the stack, and also be conducive to controlling the temperature of the stack.

[0064] Specifically, in combination with Figure 2 to Figure 5 , each stack 101_i in the normal working state is controlled at least in the following ways: first, the relay switch Pi configured for the stack 101_i is controlled to be in the closed state; second, the first input electromagnetic valve 111_i and the first output electromagnetic valve 112_i configured for the stack 101_i are controlled to be in the open state at the preset opening degree, and the air compressor 121 is controlled to operate at the pre-marked demand speed; third, the second input electromagnetic valve 131_i and the second output electromagnetic valve 132_i configured for the stack 101_i are controlled to be in the fully open state (i.e. the opening degree is 100%), and the hydrogen injection valve 141 is controlled to operate according to the pre-marked first demand condition, which can cover hydrogen flow, hydrogen pressure, response time and opening degree of the hydrogen injection valve 141, etc.; fourth, the third input electromagnetic valve 151_i and the third output electromagnetic valve 152_i configured for the stack 101_i are controlled to be in the fully open state (i.e. the opening degree is 100%), and the electric water pump 162 is controlled to operate according to the pre-marked second demand condition, which can cover the speed demand of the motor configured for the electric water pump 162, etc.

[0065] In step S201 of some embodiments, the current vehicle demand power is directly provided by the vehicle controller, which can be understood as a power demand instruction issued by the vehicle controller to the fuel cell engine according to the current vehicle operating state and / or the driver's operation.

[0066] In step S202 of some embodiments, the current vehicle demand power range to which the current vehicle demand power belongs can be filtered out in a preset table recording a plurality of continuous non-intersecting vehicle demand power ranges and the corresponding number of stacks working in each vehicle demand power range. Then, the number of all stacks currently in normal working state is subtracted from the number of stacks corresponding to the filtered vehicle demand power range, so as to obtain the number of stacks currently needed to be closed.

[0067] Exemplarily, when the above-mentioned multi-stack parallel controllable fuel cell system is applied to a long-distance tractor, since the long-distance tractor is generally matched with a 360 kW fuel cell engine, six stacks need to be designed in the multi-stack parallel controllable fuel cell system, and a preset table is set and named as a vehicle demand power-stack working number rule table, as shown in Table 1. If the current vehicle demand power issued by the vehicle controller falls within the range of (240 kW, 300 kW], it is indicated that only five stacks need to be operated in the multi-stack parallel controllable fuel cell system, and at this time, the number of stacks currently needed to be closed is determined to be one, so as to ensure that the fuel cell is operated in a quasi-steady state with a single cell voltage range of 0.7 V-0.8 V, so as to greatly improve the service life of the fuel cell. If the current vehicle demand power issued by the vehicle controller falls within the range of (300 kW, 360 kW], it is indicated that six stacks need to be operated in the multi-stack parallel controllable fuel cell system, and no closed stack operation is needed.

[0068] Table 1 Vehicle demand power-stack working number rule table

[0069] Whole vehicle demand power range Electric pile working number (0kW, 60kW] 1 (60kW, 120kW] 2 (120kW, 180kW] 3 (180kW, 240kW] 4 (240kW, 300kW] 5 (300kW, 360kW] 6

[0070] In step S204 of some embodiments, the historical running parameter values of the plurality of stacks include the historical working time lengths of the plurality of stacks, which can be provided by an FCU (Fuel cell Control Unit, fuel cell controller) device. According to the number of stacks currently needed to be closed and the historical running parameter values of the plurality of stacks, all target stacks currently needed to be closed are filtered out from the plurality of stacks, and the corresponding implementation manner is as follows:

[0071] The historical working time of each of the plurality of stacks is determined, and the stacks with the longest historical working time are selected from the plurality of stacks as the target stacks to be closed.

[0072] Specifically, the number of stacks to be closed is denoted as K, the plurality of stacks are arranged in descending order of the historical working time, and the K stacks arranged at the front are selected as the target stacks to be closed; or the plurality of stacks are arranged in ascending order of the historical working time, and the K stacks arranged at the rear are selected as the target stacks to be closed.

[0073] In a case where it is determined that the closing operation needs to be performed according to the current demand power of the vehicle, the stacks with a longer historical working time are preferentially selected for closing, which is beneficial to balancing the total working time of each stack.

[0074] In step S204 of some embodiments, the historical running parameter value of the plurality of stacks includes the average cell voltage of the plurality of stacks, which can be provided by the FCU device. The average cell voltage of each stack mainly reflects the performance degradation of the stack, which is obtained by dividing the total output voltage of the stack in a specific state by the number of all cells contained in the stack. The specific state can be understood as the last idle state of the vehicle. According to the number of stacks to be closed and the historical running parameter value of the plurality of stacks, the target stacks to be closed are selected from the plurality of stacks, and the corresponding implementation manner is as follows:

[0075] The stacks with the smallest average cell voltage are selected from the plurality of stacks as the target stacks to be closed, and the number of the selected stacks matches the number of stacks to be closed.

[0076] Specifically, the number of stacks to be closed is denoted as K, the plurality of stacks are arranged in descending order of the average cell voltage, and the K stacks arranged at the rear are selected as the target stacks to be closed; or the plurality of stacks are arranged in ascending order of the average cell voltage, and the K stacks arranged at the front are selected as the target stacks to be closed.

[0077] In a case where it is determined that the closing operation needs to be performed according to the current demand power of the vehicle, the stacks with a smaller average cell voltage are preferentially selected for closing, which is beneficial to balancing the performance degradation of each stack, i.e., balancing the output performance of each stack under the same current.

[0078] In step S204 of some embodiments, the target stacks are controlled to perform the closing operation, and the corresponding implementation manner includes the following:

[0079] For each target stack, the relay switch configured for the target stack is controlled to be in an off state; the first electromagnetic valve group configured for the target stack is controlled to be in a fully open state, and then the air supply module is controlled to perform air purging on the target stack for a first preset time length, that is, the air supply module is constrained to provide a large flow of air to the target stack; the first electromagnetic valve group configured for the target stack is controlled to be in a fully closed state, and then the target stack is controlled to perform oxygen consumption discharge for a second preset time length; the second electromagnetic valve group configured for the target stack is controlled to be in a fully closed state, and then the third electromagnetic valve group configured for the target stack is controlled to be in a fully closed state after a third preset time length.

[0080] The second preset time length is less than the third preset time length, and the third preset time length is less than or equal to the first preset time length; preferably, the first preset time length is selected in the range of [20s, 40s], the second preset time length is selected in the range of [3s, 5s], and the third preset time length is set to 20s.

[0081] Exemplarily, in combination with Figure 2 to Figure 5 When it is determined that the stack 101_1 is the target stack currently needed to be closed, the relay switch P1 configured for the stack 101_1 is controlled to be in an off state, at which time the current adjustment change is performed by the DC-DC converter; the first input electromagnetic valve 111_1 and the first output electromagnetic valve 112_1 configured for the stack 101_1 are controlled to be in a fully open state (i.e., the opening degree is 100%), and then the air supply module is controlled to perform air purging on the stack 101_1 with a large flow and for a first preset time length; the first input electromagnetic valve 111_1 and the first output electromagnetic valve 112_1 configured for the stack 101_1 are controlled to be in a fully closed state (i.e., the opening degree is 0%), and then the stack 101_1 is controlled to perform oxygen consumption discharge for a second preset time length; the second input electromagnetic valve 131_1 and the second output electromagnetic valve 132_1 configured for the stack 101_1 are controlled to be in a fully closed state (i.e., the opening degree is 0%), and then the third input electromagnetic valve 151_1 and the third output electromagnetic valve 152_1 configured for the stack 101_1 are controlled to be in a fully closed state (i.e., the opening degree is 0%) after a third preset time length, thereby achieving the closing operation of the stack 101_1.

[0082] By controlling the target stack to perform the closing operation according to a specific flow, that is, first cutting off the influence of the high-voltage power module on the target stack, then cutting off the influence of the air supply module on the target stack, then cutting off the influence of the hydrogen supply module on the target stack, and finally cutting off the influence of the thermal management module on the target stack, the target stack can safely stop the electrochemical reaction and be effectively heat managed, thereby ensuring that the target stack is not damaged.

[0083] It should be noted that after determining all target stacks that need to be closed at present, all target stacks can be simultaneously controlled to perform the closing operation, or a sequence can be formulated according to the historical running parameter values of all target stacks, and then all target stacks are controlled to perform the closing operation according to the sequence.

[0084] Specifically, in some embodiments, the historical running parameter values of all target stacks include historical working time lengths of all target stacks, and a sequence is formulated according to the historical working time lengths of all target stacks, the sequence is mainly used to limit target stacks with relatively long historical working time lengths to be closed preferentially, and then all target stacks are controlled to perform the closing operation according to the sequence.

[0085] Specifically, in some embodiments, the historical running parameter values of all target stacks include average single-cell voltages of all target stacks, and a sequence is formulated according to the average single-cell voltages of all target stacks, the sequence is mainly used to limit target stacks with relatively small average single-cell voltages to be closed preferentially, and then all target stacks are controlled to perform the closing operation according to the sequence.

[0086] The closing stack control method proposed in the embodiments of the present application is beneficial to balancing the running life of multiple stacks by determining target stacks that need to be closed at present and performing the closing operation on the target stacks according to the historical running parameter values of multiple stacks when the power demand is relatively small.

[0087] In addition, the embodiments of the present application also provide a vehicle, which includes the above-mentioned multiple-stack parallel controllable fuel cell system. The vehicle generally needs to have sufficient power and endurance capacity. The vehicle can be a heavy truck, such as a long-distance tractor, a mine truck, etc. The vehicle can also be a bus, such as a city bus, a long-distance passenger bus, etc. The present application does not limit this.

[0088] It can be understood that the contents in the above-mentioned system embodiments are all applicable to the vehicle embodiments. The vehicle embodiments specifically realize the same functions as the above-mentioned system embodiments, and achieve the same beneficial effects as the above-mentioned system embodiments.

[0089] Although the description of the present application has been quite detailed and particularly described for several embodiments, it is not intended to be limited to any of these details or embodiments or any special embodiment, but should be considered to effectively cover the intended scope of the present application by referring to the appended claims, taking into account the prior art to provide a broad interpretation of the claims. In addition, the present application is described above in embodiments that the inventors can foresee, the purpose of which is to provide a useful description, and non-essential modifications to the present application that have not yet been foreseen can still represent equivalent modifications of the present application.

Claims

1. A closed-loop control method, characterized in that, The closed-loop control method includes: When multiple electrically parallel fuel cells are in normal working condition, obtain the current power demand of the entire vehicle; Based on the current power demand of the vehicle, determine the number of fuel cells that need to be shut down. When the number of fuel cells is greater than zero, obtain the historical operating parameter values ​​of the multiple fuel cells; Based on the number of fuel cells and the historical operating parameter values ​​of the multiple fuel cells, select all target fuel cells that need to be shut down from the multiple fuel cells, and then control all target fuel cells to perform shutdown operations; The step of selecting all target electric fuel cells that need to be shut down from the plurality of electric fuel cells based on the number of fuel cells and the historical operating parameter values ​​of the plurality of fuel cells includes: The historical operating parameter values ​​of the multiple fuel cell stacks include the historical operating time of the multiple fuel cell stacks. Select all fuel cell stacks with the longest historical operating time that match the number of fuel cell stacks from the multiple fuel cell stacks. Select all the selected fuel cell stacks as the target fuel cell stacks that need to be shut down. Alternatively, the historical operating parameter values ​​of the multiple stacks include the average individual voltage of the multiple stacks. The stacks with the lowest average individual voltage that match the number of stacks are selected from the multiple stacks, and the selected stacks are taken as the target stacks that need to be shut down.

2. The closed-loop control method according to claim 1, characterized in that, The closed-stack control method is applied to a multi-stack parallel controllable fuel cell system, which includes a stack module, a high-voltage power module, a single switch module, an air supply module, a first solenoid valve module, a hydrogen supply module, a second solenoid valve module, a thermal management module, and a third solenoid valve module. The fuel cell module includes a plurality of fuel cells, the positive terminal of each fuel cell is connected to the positive terminal of the high-voltage power module to form an electrical circuit, and the negative terminal of each fuel cell is connected to the negative terminal of the high-voltage power module. The single-switch module includes a single-switch unit configured for each of the fuel cell stacks. The single-switch unit includes a relay switch and a unidirectional diode. The relay switch and the unidirectional diode are disposed on the electrical line associated with the positive terminal of the fuel cell stack. The positive terminal of the high-voltage power module is connected to the positive terminal of the fuel cell stack in sequence through the relay switch and the unidirectional diode. The first solenoid valve module includes a first solenoid valve group configured for each of the fuel cell stacks, the first solenoid valve group being used to control the air supply module to supply air to the fuel cell stacks; The second solenoid valve module includes a second solenoid valve group configured for each of the fuel cell stacks, the second solenoid valve group being used to control the hydrogen supply module to supply hydrogen to the fuel cell stacks; The third solenoid valve module includes a third solenoid valve group configured for each of the fuel cell stacks, the third solenoid valve group being used to control the thermal management module to supply coolant to the fuel cell stacks.

3. The closed-loop control method according to claim 2, characterized in that, Each of the fuel cell stacks is in a normal operating state including: the relay switch configured for the fuel cell stack is in a closed state, the first solenoid valve group configured for the fuel cell stack is in an open state at a preset opening degree, and the second and third solenoid valve groups configured for the fuel cell stack are in a fully open state.

4. The closed-loop control method according to claim 2, characterized in that, The process of controlling all target fuel cell stacks to shut down includes: For each of the target fuel cell stacks, the relay switch configured for the target fuel cell stack is in the off state; The first solenoid valve group configured for the target fuel cell stack is controlled to be fully open, and then the air supply module is controlled to purge the target fuel cell stack with air for a first preset duration. The first solenoid valve group configured for the target fuel cell stack is controlled to be fully closed, and then the target fuel cell stack is controlled to perform oxygen-consuming discharge for a second preset duration. The second solenoid valve group configured for the target fuel cell stack is controlled to be fully closed, and then after a third preset time period, the third solenoid valve group configured for the target fuel cell stack is controlled to be fully closed.

5. The closed-loop control method according to claim 2, characterized in that, The first solenoid valve group configured for each of the fuel cell stacks includes a first input solenoid valve and a first output solenoid valve. The cathode inlet of the fuel cell stack is connected to the air supply module through the first input solenoid valve, and the cathode outlet of the fuel cell stack is connected to the air supply module through the first output solenoid valve.

6. The closed-loop control method according to claim 2, characterized in that, The second solenoid valve group configured for each of the fuel cell stacks includes a second input solenoid valve and a second output solenoid valve. The anode inlet of the fuel cell stack is connected to the hydrogen supply module through the second input solenoid valve, and the anode outlet of the fuel cell stack is connected to the hydrogen supply module through the second output solenoid valve.

7. The closed-loop control method according to claim 2, characterized in that, The third solenoid valve group configured for each fuel cell stack includes a third input solenoid valve and a third output solenoid valve. The coolant inlet of the fuel cell stack is connected to the thermal management module through the third input solenoid valve, and the coolant outlet of the fuel cell stack is connected to the thermal management module through the third output solenoid valve.

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