Multi-stack parallel controllable fuel cell system, stack closing control method and vehicle

Abstract

The invention provides a multi-stack parallel controllable fuel cell system, a stack closing control method and a vehicle, and belongs to the technical field of fuel cells. The system comprises a galvanic pile module, a high-voltage power module, a single switch module, an air supply module, a hydrogen supply module and a thermal management module, the galvanic pile module comprises a plurality of galvanic piles which are electrically connected in parallel, and the positive electrode end of each galvanic pile is connected with the positive electrode end of the high-voltage power module to form an electrical circuit; the single switch module comprises a single switch unit configured for each galvanic pile, and the single switch unit comprises a relay switch and a unilateral diode which are arranged on an electrical circuit related to the positive end of the galvanic pile; the system further comprises a first electromagnetic valve module used for controlling the air supply module to independently provide air for the multiple electric piles, a second electromagnetic valve module used for controlling the hydrogen supply module to independently provide hydrogen for the multiple electric piles, and a third electromagnetic valve module used for controlling the heat management module to independently provide cooling liquid for the multiple electric piles. The service life of the fuel cell system can be prolonged.

Description

Technical Field

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

[0002] In the existing technology, most fuel cells use multiple stacks in parallel to achieve high power output, by evenly distributing the power required by the whole vehicle to each stack and ensuring the uniformity of the distribution of water, hydrogen and air in the stack. However, since the vehicle still needs low power output and idling during use, if the smaller power required by the whole vehicle is evenly distributed to each stack, this will cause each cell in the stack to be at a high potential, thus affecting the operating life of the stack. Summary of the invention

[0003] The main purpose of this application is to propose a multi-stack parallel controllable fuel cell system, a closed stack 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, including a fuel cell 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;

[0005] The battery stack module includes a plurality of battery stacks electrically connected in parallel, the positive terminal of each battery stack is connected to the positive terminal of the high-voltage power module to form an electrical circuit, and the negative terminal of each battery stack is connected to the negative terminal of the high-voltage power module;

[0006] The single switch module includes a single switch unit configured for each of the battery stacks, the single switch unit includes a relay switch and a unidirectional diode, the relay switch and the unidirectional diode are arranged on the electrical circuit related to the positive terminal of the battery stack, and the positive terminal of the high-voltage power module is connected to the positive terminal of the battery stack in turn through the relay switch and the unidirectional diode;

[0007] The first solenoid valve module includes a first solenoid valve group configured for each of the fuel cell stacks, and the first solenoid valve group is used to control the air supply module to provide air to the fuel cell stack;

[0008] The second solenoid valve module includes a second solenoid valve group configured for each of the fuel cell stacks, and the second solenoid valve group is used to control the hydrogen supply module to provide hydrogen to the fuel cell stack;

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

[0010] Furthermore, 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.

[0011] Furthermore, the second solenoid valve group configured for each fuel cell stack 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.

[0012] Furthermore, the third solenoid valve group configured for each of the fuel cell stacks 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.

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

[0014] When multiple battery stacks connected in parallel are in normal working condition, the current required power of the whole vehicle is obtained;

[0015] Determine the number of battery stacks that need to be shut down according to the current vehicle power demand;

[0016] When the number of the battery stacks is greater than zero, obtaining historical operating parameter values ​​of the multiple battery stacks;

[0017] According to the number of the fuel cell stacks and the historical operating parameter values ​​of the multiple fuel cell stacks, all target fuel cell stacks that currently need to be shut down are screened out from the multiple fuel cell stacks, and then all the target fuel cell stacks are controlled to perform a shutdown operation.

[0018] Furthermore, each of the fuel cell stacks is in a normal working 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 solenoid valve group and the third solenoid valve group configured for the fuel cell stack are in a fully open state.

[0019] Further, controlling all target fuel cells to perform shutdown operations includes:

[0020] For each of the target fuel cells, controlling a relay switch configured for the target fuel cell to be in an off state;

[0021] Controlling a first solenoid valve group configured for the target fuel cell stack to be in a fully open state, and then controlling an air supply module to perform air purge on the target fuel cell stack for a first preset time period;

[0022] Controlling a first solenoid valve group configured for the target fuel cell stack to be in a fully closed state, and then controlling the target fuel cell stack to perform oxygen-consuming discharge for a second preset time;

[0023] The second solenoid valve group configured for the target fuel cell stack is controlled to be in a fully closed state, and then after a third preset time period, the third solenoid valve group configured for the target fuel cell stack is controlled to be in a fully closed state.

[0024] Further, the historical operating parameter values ​​of the plurality of fuel cells include historical working hours of the plurality of fuel cells; and selecting all target fuel cells that need to be shut down from the plurality of fuel cells according to the number of fuel cells and the historical operating parameter values ​​of the plurality of fuel cells includes:

[0025] All the battery stacks with the longest historical working time that match the number of battery stacks are screened out from the multiple battery stacks, and all the screened out battery stacks are used as all the target battery stacks that need to be shut down currently.

[0026] Further, the historical operating parameter values ​​of the plurality of battery stacks include an average cell voltage of the plurality of battery stacks; and selecting all target battery stacks that need to be shut down from the plurality of battery stacks according to the number of battery stacks and the historical operating parameter values ​​of the plurality of battery stacks includes:

[0027] All the battery stacks with the smallest average cell voltage and matching the number of battery stacks are screened out from the multiple battery stacks, and all the screened out battery stacks are used as all the target battery stacks that need to be shut down currently.

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

[0029] The present application at least includes the following beneficial effects: when multiple stacks are in an electrical parallel state, by configuring a single switch unit for each stack to control the connection relationship between the stack and the high-voltage power module, by configuring a first solenoid valve group for each stack to control the connection relationship between the stack and the air supply module, by configuring a second solenoid valve group for each stack to control the connection relationship between the stack and the hydrogen supply module, and by configuring a third solenoid valve group for each stack to control the connection relationship between the stack and the thermal management module, multiple stacks can be made to work simultaneously to achieve high power output, and some of the stacks can be made to work simultaneously when the power demand is relatively small to avoid the fuel cell system being at a high potential and causing attenuation such as carbon corrosion, so that the fuel cell system can be guaranteed to have a wide power range output and the operating life of the fuel cell system can be improved. By determining the target stack that needs to be shut down according to the historical operating parameter values ​​of multiple stacks when the power demand is relatively small and shutting it down, it is beneficial to balance the operating life of multiple stacks. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the structure of a multi-stack parallel controllable fuel cell system provided in an embodiment of the present application;

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

[0032] Figure 3 It is a schematic diagram of the structure of the combined fuel cell stack module, the air supply module and the first solenoid valve module provided in an embodiment of the present application;

[0033] Figure 4 It is a schematic diagram of the structure of the combined fuel cell module, the hydrogen supply module and the second solenoid valve module provided in an embodiment of the present application;

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

[0035] Figure 6 It is a flow chart of a closed stack control method provided in an embodiment of the present application. DETAILED DESCRIPTION

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

[0037] It is understood that the terms "first", "second", etc. used in this application can be used in this article 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 concept. 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 those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0039] In the prior art, with the gradual emergence of high-power scenarios for vehicles, traditional single-stack fuel cells can only achieve high-power output by increasing the number of monomers or the active area of ​​the monomers, but this will bring other application disadvantages, such as uneven distribution of current flowing through the monomers, uneven distribution of reactants required by the monomers, etc. In order to overcome the application disadvantages of single-stack fuel cells themselves, some people on the market have proposed to use multiple parallel fuel cells to achieve high-power output, by evenly distributing the power required by the whole vehicle to each stack, and ensuring the uniformity of the distribution of water, hydrogen and air media in the stack. However, since the vehicle will still have the need for low-power output and idling during use, if the smaller power required by the whole vehicle 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] In view of this, the embodiment of the present application provides a multi-stack parallel controllable fuel cell system, a closed stack control method and a vehicle. When multiple stacks are in an electrical parallel state, by configuring a single switch unit for each stack to control the connection relationship between the stack and the high-voltage power module, by configuring a first solenoid valve group for each stack to control the connection relationship between the stack and the air supply module, by configuring a second solenoid valve group for each stack to control the connection relationship between the stack and the hydrogen supply module, by configuring a third solenoid valve group for each stack to control the connection relationship between the stack and the thermal management module, multiple stacks can be made to work simultaneously to achieve high power output, and some of the stacks can be made to work simultaneously when the power demand is relatively small to avoid the fuel cell system being at a high potential and causing attenuation such as carbon corrosion, so that the fuel cell system can be ensured to have a wide power range output and the operating life of the fuel cell system can be improved. By determining the target stack that needs to be shut down according to the historical operating parameter values ​​of multiple stacks when the power demand is relatively small and shutting it down, it is beneficial to balance the operating life of multiple stacks.

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

[0042] Specifically, see Figure 2 As shown, the battery stack module includes multiple battery stacks electrically connected in parallel, at this time, the positive ends of the battery stacks 101_1 to 101_N are connected together, the negative ends of the battery stacks 101_1 to 101_N are connected together, the positive end of each battery stack 101_i is connected to the positive end of the high-voltage power module to form an electrical circuit, and the negative end of each battery stack 101_i is connected to the negative end of the high-voltage power module, i=1,2,...,N, N is the number of multiple battery stacks.

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

[0044] By arranging the unidirectional diode Di on the electrical circuit formed between the positive terminal of the battery stack 101_i and the positive terminal of the high-voltage power module, it can be ensured that the current of the high-voltage power module flows in one direction during power conversion, avoiding adverse situations such as stack burning caused by current cross-talk with other battery stacks.

[0045] In some embodiments, the high-voltage power module includes a DC-DC converter. For each fuel cell stack 101_i and a single switch unit configured therefor, the positive terminal of the DC-DC converter is connected to the positive terminal of the fuel cell stack 101_i via the single switch unit, and the negative terminal of the DC-DC converter is connected to the negative terminal of the fuel cell stack 101_i. 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 fuel cell stack 101_i.

[0046] It should be noted that the present application sets multiple battery stacks to an electrical parallel working mode, and the prerequisite is that: when the specifications and performance of each battery stack 101_i are the same, determine N×M×U 0 ≥U B This expression is valid, N is the number of multiple battery stacks, M is the number of all monomers contained in the battery stack, U 0 is the maximum instantaneous output voltage of the battery stack and is generally about 1V. B The reference voltage level of the vehicle voltage platform. For example, the reference voltage level of the vehicle voltage platform designed for common commercial vehicles is 600V.

[0047] In addition, the following explanation is given about the selection of the DC-DC converter: B / U 0 When this expression is established, that is, the battery stack is designed according to the basic requirements, it is determined that the DC-DC converter adopts a boost DC-DC converter; when M≥U B / U 0 ​When this expression is true, that is, the battery stack is designed according to special requirements, it is determined that the DC-DC converter adopts a buck-boost DC-DC converter, and when the operating voltage of the battery stack is low, the DC-DC converter operates in boost mode, and when the operating voltage of the battery stack exceeds the reference voltage level of the vehicle voltage platform, the DC-DC converter operates in buck mode.

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

[0049] In some embodiments, see Figure 3 As shown, the first solenoid valve group configured for each stack 101_i includes a first input solenoid valve 111_i and a first output solenoid valve 112_i. The cathode inlet of the stack 101_i is connected to the air supply module through the first input solenoid valve 111_i, and the cathode outlet of the stack 101_i is connected to the air supply module through the first output solenoid valve 112_i. By arranging the first input solenoid valve 111_i at the cathode inlet of the stack 101_i and the first output solenoid 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, ensuring 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, see Figure 3As shown, the air supply module includes an air compressor 121, a humidifier 122 and an expander 123. For the first input solenoid valve 111_i and the first output solenoid valve 112_i configured for each fuel cell 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 fuel cell stack 101_i through the first input solenoid valve 111_i, so that the air in the atmospheric environment is transported to the fuel cell stack 101_i through the first input solenoid valve 111_i after being processed by the air compressor 121 and the humidifier 122 in sequence. The stack 101_i performs an electrochemical reaction; the cathode outlet of the stack 101_i is connected to the second inlet of the humidifier 122 through the first output solenoid valve 112_i, the second outlet of the humidifier 122 is connected to the inlet of the expander 123, the outlet of the expander 123 is connected to the atmospheric environment, 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 from the stack 101_i with the air delivered by the air compressor 121, and then the expander 123 can recover the energy of the gas discharged from the humidifier 122 and use it to reduce the power consumption of the air compressor 121.

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

[0052] In some embodiments, see Figure 4 As shown, the second solenoid valve group configured for each stack 101_i includes a second input solenoid valve 131_i and a second output solenoid valve 132_i. The anode inlet of the stack 101_i is connected to the hydrogen supply module through the second input solenoid valve 131_i, and the anode outlet of the stack 101_i is connected to the hydrogen supply module through the second output solenoid valve 132_i. By arranging the second input solenoid valve 131_i at the anode inlet of the stack 101_i and arranging the second input solenoid valve 131_i at the anode outlet of the stack 101_i, it is beneficial to more effectively cut off the hydrogen supply process of the stack 101_i, ensuring that no hydrogen, nitrogen and moisture enter when the stack 101_i is closed.

[0053] In some embodiments, see Figure 4As shown, the hydrogen supply module includes a hydrogen injection valve 141, a hydrogen inlet pressure stabilizing chamber 142, a gas-water separator 143, a hydrogen discharge valve 144, and an injector 145_i and an ejector 146_i configured for each fuel cell 101_i. For the second input solenoid valve 131_i and the second output solenoid valve 132_i configured for each fuel cell 101_i, an external hydrogen supply device is connected to the inlet of the hydrogen inlet pressure stabilizing chamber 142 through the hydrogen injection valve 141, the outlet of the hydrogen inlet pressure stabilizing chamber 142 is connected to the inlet of the injector 145_i, the outlet of the injector 145_i is connected to the first inlet of the ejector 146_i, and the outlet of the ejector 146_i is connected to the anode inlet of the fuel cell 101_i through the second input solenoid valve 131_i, so that the hydrogen supply device After being processed by the hydrogen inlet pressure stabilizing chamber 142, the injector 145_i and the ejector 146_i in sequence, the hydrogen is transported to the fuel cell stack 101_i through the second input solenoid valve 131_i for electrochemical reaction; the anode outlet of the fuel cell stack 101_i is connected to the inlet of the gas-water separator 143 through the second output solenoid valve 132_i, the first outlet of the gas-water separator 143 is connected to the second inlet of the ejector 146_i, and the second outlet of the gas-water separator 143 is connected to the atmospheric environment through the hydrogen discharge valve 144, so that the gas-water separator 143 can separate the liquid water and gas of the hydrogen discharged from the fuel cell stack 101_i, and then transport the separated hydrogen to the fuel cell stack 101_i via the ejector 146_i for recycling and reuse.

[0054] Specifically, the third solenoid valve module includes a third solenoid valve group configured for each fuel cell stack 101_i, and the third solenoid valve group is used to control the thermal management module to provide coolant to the fuel cell stack 101_i.

[0055] In some embodiments, see Figure 5 As shown, the third solenoid valve group configured for each stack 101_i includes a third input solenoid valve 151_i and a third output solenoid valve 152_i. The coolant inlet of the stack 101_i is connected to the thermal management module through the third input solenoid valve 151_i, and the coolant outlet of the stack 101_i is connected to the thermal management module through the third output solenoid valve 152_i. By arranging the third input solenoid valve 151_i at the coolant inlet of the stack 101_i and the third output solenoid valve 152_i at the coolant outlet of the stack 101_i, it is beneficial to more effectively cut off the coolant supply process of the stack 101_i, ensuring that no coolant enters when the stack 101_i is closed.

[0056] In some embodiments, see Figure 5As shown, the thermal 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 provided on the radiator 165 to improve the heat dissipation efficiency. For the third input solenoid valve 151_i and the third output solenoid valve 152_i configured for each battery stack 101_i, the outlet of the expansion water tank 161 is connected to the inlet of the electric water pump 162, and the outlet of the electric water pump 162 is connected to the inlet of the electric water pump 162 through the third input solenoid valve 151_i. The coolant inlet of the battery stack 101_i is connected, and the coolant outlet of the battery stack 101_i is connected to the inlet of the electronic thermostat 163 through the third output solenoid valve 152_i. The first outlet of the electronic thermostat 163 is connected to the inlet of the deionizer 164, and the outlet of the deionizer 164 is connected to the inlet of the electric water pump 162. The second outlet of the electronic thermostat 163 is connected to the inlet of the radiator 165, and the outlet of the radiator 165 is connected to the inlet of the electric water pump 162.

[0057] The multi-stack parallel controllable fuel cell system provided in the embodiment of the present application, when the multiple stacks are in an electrically parallel state, by configuring a single switch unit for each stack to control the connectivity between the stack and the high-voltage power module, by configuring a first solenoid valve group for each stack to control the connectivity between the stack and the air supply module, by configuring a second solenoid valve group for each stack to control the connectivity between the stack and the hydrogen supply module, by configuring a third solenoid valve group for each stack to control the connectivity between the stack and the thermal management module, multiple stacks can be operated simultaneously to achieve high power output, and some of the stacks can be operated simultaneously when the power demand is relatively small to avoid the fuel cell system being at a high potential and causing attenuation phenomena such as carbon corrosion. This can not only ensure that the fuel cell system has a wider power range output, but also improve the operating life of the fuel cell system.

[0058] Figure 6 is an optional flow chart of a closed stack control method provided in an embodiment of the present application, which is mainly applied to the above-mentioned multi-stack parallel controllable fuel cell system. Figure 6 The method may include but is not limited to steps S201 to S204:

[0059] Step S201: when the multiple battery stacks electrically connected in parallel are in a normal working state, obtaining the current required power of the entire vehicle;

[0060] Step S202: Determine the number of battery stacks that need to be shut down according to the current vehicle power demand;

[0061] Step S203: when the number of the battery stacks is greater than zero, obtaining historical operating parameter values ​​of multiple battery stacks;

[0062] Step S204: based on the number of the fuel cells and the historical operating parameter values ​​of the plurality of fuel cells, all target fuel cells that need to be shut down are screened out from the plurality of fuel cells, and then all the target fuel cells are controlled to perform a shutdown operation.

[0063] In step S201 of some embodiments, each fuel cell stack is in a normal working 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, and the second solenoid valve group and the third solenoid valve group configured for the fuel cell stack are in a fully open state; wherein the preset opening of the first solenoid valve group is preferably set to 80%, which can constrain the air supply module to provide an appropriate flow of air to the fuel cell stack, thereby avoiding accelerated aging of the fuel cell stack and is also beneficial to controlling the temperature of the fuel cell stack.

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

[0065] In step S201 of some embodiments, the current vehicle power demand 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 driver operation.

[0066] In step S202 of some embodiments, a preset table can be queried, which records multiple continuous non-overlapping vehicle power demand ranges and the number of working battery stacks corresponding to each vehicle power demand range. First, the vehicle power demand range to which the current vehicle power demand belongs is filtered out in the preset table, and then the number of all battery stacks currently in normal working condition is subtracted from the filtered number of working battery stacks corresponding to the vehicle power demand range to obtain the number of battery stacks that currently need to be shut down.

[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 equipped with a 360kW fuel cell engine, it is necessary to design 6 stacks in the multi-stack parallel controllable fuel cell system, and set a preset table and name it as the vehicle demand power-stack working quantity rule table, as shown in Table 1; if the current vehicle demand power issued by the vehicle controller falls within the range of (240kW, 300kW], it means that only 5 stacks are required to operate in the multi-stack parallel controllable fuel cell system. At this time, it is determined that the number of stacks that need to be shut down is 1, ensuring that the fuel cell operates in a quasi-steady state in the single cell voltage range of 0.7V-0.8V, 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 (300kW, 360kW], it means that 6 stacks are required to operate in the multi-stack parallel controllable fuel cell system, and no stack closing operation is required.

[0068] Table 1 Vehicle power requirement-battery stack working quantity rules

[0069] Vehicle power requirement range Number of working cells (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 operating parameter values ​​of the plurality of fuel cells include the historical working hours of the plurality of fuel cells, which may be provided by an FCU (Fuel cell Control Unit) device; according to the number of fuel cells that currently need to be shut down and the historical operating parameter values ​​of the plurality of fuel cells, all target fuel cells that currently need to be shut down are screened out from the plurality of fuel cells, and the corresponding implementation method is as follows:

[0071] All the battery stacks with the longest historical working time and matching the number of battery stacks that currently need to be shut down are screened out from multiple battery stacks, and then all the screened out battery stacks are used as all the target battery stacks that currently need to be shut down.

[0072] Specifically, the number of battery stacks that currently need to be shut down is recorded as K, and multiple battery stacks are arranged in descending order according to the historical working time, and the K battery stacks arranged in the front are used as all the target battery stacks that currently need to be shut down; or, multiple battery stacks are arranged in ascending order according to the historical working time, and the K battery stacks arranged in the back are used as all the target battery stacks that currently need to be shut down.

[0073] When it is determined that a stack shutdown operation needs to be performed based on the current power demand of the entire vehicle, the total operating time of each stack can be balanced by giving priority to shutting down the stacks with longer historical operating time.

[0074] In step S204 of some embodiments, the historical operating parameter values ​​of the plurality of battery stacks include the average cell voltage of the plurality of battery stacks, which may be provided by the FCU device. The average cell voltage of each battery stack mainly reflects the degree of performance degradation of the battery stack, which is obtained by dividing the total output voltage of the battery stack in a specific state by the number of all cells contained in the battery stack. The specific state may be understood as the most recent idle state of the vehicle. According to the number of battery stacks that currently need to be shut down and the historical operating parameter values ​​of the plurality of battery stacks, all target battery stacks that currently need to be shut down are screened out from the plurality of battery stacks. The corresponding implementation method is as follows:

[0075] All the battery stacks with the smallest average cell voltage and matching the number of battery stacks that currently need to be shut down are screened out from multiple battery stacks, and then all the screened out battery stacks are used as all the target battery stacks that currently need to be shut down.

[0076] Specifically, the number of battery stacks that currently need to be shut down is recorded as K, and multiple battery stacks are arranged in order from large to small according to the average single cell voltage, and the K battery stacks arranged at the back are used as all the target battery stacks that currently need to be shut down; or, multiple battery stacks are arranged in order from small to large according to the average single cell voltage, and the K battery stacks arranged at the front are used as all the target battery stacks that currently need to be shut down.

[0077] When it is determined that a stack shutdown operation needs to be performed based on the current power demand of the entire vehicle, by giving priority to shutting down stacks with smaller average cell voltages, it is beneficial to balance the performance degradation of each stack, that is, to balance the output performance of each stack at the same current.

[0078] In step S204 of some embodiments, all target stacks are controlled to perform a shutdown operation, and corresponding implementations include the following:

[0079] For each target fuel cell stack, the relay switch configured for the target fuel cell stack is controlled to be in the disconnected state; the first solenoid valve group configured for the target fuel cell stack is controlled to be in the fully open state, and then the air supply module is controlled to perform air blowing on the target fuel cell stack for a first preset time, that is, the air supply module is constrained to provide a larger flow of air to the target fuel cell stack; the first solenoid valve group configured for the target fuel cell stack is controlled to be in the fully closed state, and then the target fuel cell stack is controlled to perform oxygen-consuming discharge for a second preset time; the second solenoid valve group configured for the target fuel cell stack is controlled to be in the fully closed state, and then after a third preset time, the third solenoid valve group configured for the target fuel cell stack is controlled to be in the fully closed state.

[0080] Among them, 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 within the range of [20s, 40s], the second preset time length is selected within the range of [3s, 5s], and the third preset time length is set to 20s.

[0081] For example, in combination Figures 2 to 5 When it is determined that the battery stack 101_1 is the target battery stack that needs to be shut down, the relay switch P1 configured for the battery stack 101_1 is controlled to be in an off state, and the DC-DC converter is used to adjust the current; the first input solenoid valve 111_1 and the first output solenoid valve 112_1 configured for the battery stack 101_1 are controlled to be in a fully open state (i.e., the opening is 100%), and then the air supply module is controlled to perform a large flow of air purge on the battery stack 101_1 and it needs to last for the first preset time; the first input solenoid valve 111_1 configured for the battery stack 101_1 is controlled to be in a fully open state (i.e., the opening is 100%). and the first output solenoid valve 112_1 are in a fully closed state (i.e., the opening is 0%), and then the fuel cell stack 101_1 is controlled to perform oxygen-consuming discharge and needs to last for the second preset time; the second input solenoid valve 131_1 and the second output solenoid valve 132_1 configured for the fuel cell stack 101_1 are controlled to be in a fully closed state (i.e., the opening is 0%), and then after the third preset time, the third input solenoid valve 151_1 and the third output solenoid valve 152_1 configured for the fuel cell stack 101_1 are controlled to be in a fully closed state (i.e., the opening is 0%), thereby realizing the closing operation of the fuel cell stack 101_1.

[0082] The shutdown operation is performed by controlling the target fuel cell stack according to a specific process, namely, first cutting off the influence of the high-voltage power module on the target fuel cell stack, then cutting off the influence of the air supply module on the target fuel cell stack, then cutting off the influence of the hydrogen supply module on the target fuel cell stack, and finally cutting off the influence of the thermal management module on the target fuel cell stack, so that the target fuel cell stack can safely stop the electrochemical reaction and perform effective thermal management, thereby ensuring that the target fuel cell stack is not damaged.

[0083] It should be noted that after determining all the target fuel cells that currently need to be shut down, all the target fuel cells can be controlled to be shut down at the same time; or a sequence can be formulated based on the historical operating parameter values ​​of all the target fuel cells, and then all the target fuel cells can be controlled to be shut down according to the sequence.

[0084] Specifically, in some embodiments, the historical operating parameter values ​​of all target fuel cells include the historical operating hours of all target fuel cells. A priority order is established based on the historical operating hours of all target fuel cells. The priority order is mainly used to prioritize the shutdown of target fuel cells with relatively long historical operating hours, and then all target fuel cells are controlled to perform shutdown operations according to the priority order.

[0085] Specifically, in some embodiments, the historical operating parameter values ​​of all target fuel cells include the average cell voltage of all target fuel cells. A priority order is established based on the average cell voltage of all target fuel cells. The priority order is mainly used to limit the target fuel cells with relatively small average cell voltage to be shut down first, and then all target fuel cells are controlled to perform shutdown operations according to the priority order.

[0086] The stack shutdown control method proposed in the embodiment of the present application determines the target stack that needs to be shut down currently based on the historical operating parameter values ​​of multiple stacks and performs a shutdown operation on it when the power demand is relatively small, which is beneficial to balancing the operating life of multiple stacks.

[0087] In addition, an embodiment of the present application also provides a vehicle, which includes the above-mentioned multi-stack parallel controllable fuel cell system. The vehicle generally needs to have sufficient power and endurance. The vehicle can be a heavy truck, such as a long-distance tractor, a mining 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 of the above-mentioned system embodiments are all applicable to the present vehicle embodiment, the functions specifically implemented by the present vehicle embodiment are the same as those of the above-mentioned system embodiments, and the beneficial effects achieved are also the same as those achieved by the above-mentioned system embodiments.

[0089] Although the description of the present application has been quite detailed and specifically describes several described embodiments, it is not intended to be limited to any of these details or embodiments or any particular embodiment, but should be regarded as providing a broad possible interpretation of these claims by reference to the attached claims, taking into account the prior art, so as to effectively cover the intended scope of the present application. In addition, the above description of the present application is based on the embodiments foreseeable by the inventor, and its purpose is to provide a useful description, and those non-substantial changes to the present application that have not yet been foreseen may still represent equivalent changes to the present application.

Claims

1. A multi-stack parallel controllable fuel cell system, characterized in that: It includes a battery 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 battery stack module includes a plurality of battery stacks electrically connected in parallel, the positive terminal of each battery stack is connected to the positive terminal of the high-voltage power module to form an electrical circuit, and the negative terminal of each battery stack 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 battery stacks, the single switch unit includes a relay switch and a unidirectional diode, the relay switch and the unidirectional diode are arranged on the electrical circuit related to the positive terminal of the battery stack, and the positive terminal of the high-voltage power module is connected to the positive terminal of the battery stack in turn 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, and the first solenoid valve group is used to control the air supply module to provide air to the fuel cell stack; The second solenoid valve module includes a second solenoid valve group configured for each of the fuel cell stacks, and the second solenoid valve group is used to control the hydrogen supply module to provide hydrogen to the fuel cell stack; The third solenoid valve module includes a third solenoid valve group configured for each of the fuel cell stacks, and the third solenoid valve group is used to control the thermal management module to provide coolant to the fuel cell stack.

2. The multi-stack parallel controllable fuel cell system according to claim 1, characterized in that: The first solenoid valve group configured for each fuel cell stack 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.

3. The multi-stack parallel controllable fuel cell system according to claim 1, characterized in that: The second solenoid valve group configured for each fuel cell stack 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.

4. The multi-stack parallel controllable fuel cell system according to claim 1, 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.

5. A closed stack control method, characterized in that: Applied to the multi-stack parallel controllable fuel cell system according to any one of claims 1 to 4, the closed stack control method comprises: When multiple battery stacks connected in parallel are in normal working condition, the current required power of the vehicle is obtained; Determine the number of battery stacks that need to be shut down according to the current vehicle power demand; When the number of the battery stacks is greater than zero, obtaining historical operating parameter values ​​of the multiple battery stacks; According to the number of the fuel cell stacks and the historical operating parameter values ​​of the multiple fuel cell stacks, all target fuel cell stacks that currently need to be shut down are screened out from the multiple fuel cell stacks, and then all the target fuel cell stacks are controlled to perform a shutdown operation.

6. The closed stack control method according to claim 5, characterized in that: Each of the fuel cell stacks is in a normal working 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 solenoid valve group and the third solenoid valve group configured for the fuel cell stack are in a fully open state.

7. The closed stack control method according to claim 6, characterized in that: The controlling all target fuel cells to perform shutdown operations includes: For each of the target fuel cells, controlling a relay switch configured for the target fuel cell to be in an off state; Controlling a first solenoid valve group configured for the target fuel cell stack to be in a fully open state, and then controlling an air supply module to perform air purge on the target fuel cell stack for a first preset time period; Controlling a first solenoid valve group configured for the target stack to be in a fully closed state, and then controlling the target stack to perform oxygen-consuming discharge for a second preset time; The second solenoid valve group configured for the target fuel cell stack is controlled to be in a fully closed state, and then after a third preset time period, the third solenoid valve group configured for the target fuel cell stack is controlled to be in a fully closed state.

8. The closed stack control method according to claim 5, characterized in that: The historical operating parameter values ​​of the plurality of fuel cells include historical operating hours of the plurality of fuel cells; and selecting all target fuel cells that need to be shut down from the plurality of fuel cells according to the number of fuel cells and the historical operating parameter values ​​of the plurality of fuel cells includes: All the battery stacks with the longest historical working time that match the number of battery stacks are screened out from the multiple battery stacks, and all the screened out battery stacks are used as all the target battery stacks that need to be shut down currently.

9. The closed stack control method according to claim 5, characterized in that: The historical operating parameter values ​​of the plurality of fuel cell stacks include average cell voltages of the plurality of fuel cell stacks; The step of selecting all target battery stacks that need to be shut down from the plurality of battery stacks according to the number of battery stacks and the historical operating parameter values ​​of the plurality of battery stacks includes: All the battery stacks with the smallest average cell voltage and matching the number of battery stacks are screened out from the multiple battery stacks, and all the screened out battery stacks are used as all the target battery stacks that need to be shut down currently.

10. A vehicle, characterized in that: It comprises a multi-stack parallel controllable fuel cell system as described in any one of claims 1 to 4.

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