A method and device for starting and stopping hydrogen fuel cells in a hydrogen fuel cell vehicle

Abstract

This invention relates to a method and apparatus for starting and stopping a hydrogen fuel cell in a hydrogen fuel cell vehicle, belonging to the field of hydrogen fuel cell vehicle control technology. The method includes: obtaining estimated values ​​for the start-up duration and shutdown duration of the hydrogen fuel cell; and determining the power-limited state of charge (SOC) threshold of the power battery based on the battery temperature. end Determine the SOC threshold for hydrogen fuel cell startup. FCon ; and SOC threshold SOC FCoff The state of charge (SOC) of the power battery is at its maximum. FCon and SOC FCoff During this period, in response to the SOC of the power battery dropping to the specified SOC level, FCon The hydrogen fuel cell is started, and the state of charge (SOC) of the power battery rises to the specified SOC. FCoff The hydrogen fuel cell is then shut down. The start-up and shutdown method provided by this invention can reasonably determine the start-up and shutdown timing of the hydrogen fuel cell, and uses a threshold SOC (State of Charge) to achieve this. on and threshold SOC off The configuration ensures that the hydrogen fuel cell has enough time to reduce its state of charge (SOC) to the state of fuel cell (SOC). end The previous start-up was completed in a way that met the power requirements of the vehicle without causing large fluctuations in SOC that would lead to frequent start-stop cycles.

Description

Technical Field

[0001] This invention relates to a method and apparatus for starting and stopping a hydrogen fuel cell in a hydrogen fuel cell vehicle, belonging to the field of hydrogen fuel cell vehicle control technology. Background Technology

[0002] Because hydrogen fuel cell hybrid vehicles have two power sources—a battery and a hydrogen fuel cell—the vehicle's driving power is provided by both and needs to meet real-time operating demands. A key characteristic of hydrogen fuel cell hybrid vehicle operating conditions is the relatively rapid, real-time dynamic change in the vehicle's power demand, especially in urban driving conditions where start-stop, deceleration, and braking are more frequent. Load changes, start-stop cycles, idling, and high loads all significantly impact the lifespan of hydrogen fuel cells, with frequent load changes having the largest impact, followed by start-stop cycles. Adopting a strategy where the hydrogen fuel cell power follows the vehicle's power demand would inevitably result in the hydrogen fuel cell constantly operating under dynamic load variations.

[0003] Therefore, to protect the hydrogen fuel cell, the control strategy limits the rate of power change and the range of power usage to reduce the rate of lifespan degradation, with the battery responding to faster changes in power demand. However, this may lead to greater fluctuations in the battery's SOC (State of Charge, representing the percentage of electrical charge stored in the battery) under different operating conditions, making it more prone to frequent start-stop cycles. Frequent start-stop cycles also significantly reduce the lifespan of the hydrogen fuel cell.

[0004] When a hydrogen fuel cell hybrid vehicle employs an auxiliary range-extending energy management strategy, it operates in pure electric mode during the charging of depleting (CD) phase. Once the battery charge drops to a target limit, it switches to charging of sustaining (CS) mode, operating in hydrogen hybrid mode. The hydrogen fuel cell keeps the state of charge (SOC) of the battery relatively stable. However, when using a blended range-extending control strategy, there is no independent pure electric driving mode (CD) phase, and the hydrogen fuel cell operates intermittently throughout.

[0005] When the vehicle control unit (VCU) issues a start-stop request, the hydrogen fuel cell's start-up and shutdown processes are entirely controlled independently by the fuel cell control unit (FCU). The timing of completion is not determined by the VCU; the VCU can only decide when to issue the start-stop request. More seriously, the start-stop of a hydrogen fuel cell is significantly affected by temperature. The times for warm-up, cold-up, and low-temperature cold-up, as well as the times for shutdown at normal and low temperatures, are generally much longer than those of an internal combustion engine range extender system. An internal combustion engine start-stop typically takes about 1 second, while the shortest start-up time for a hydrogen fuel cell—from warm-up to rated power—is over 10 seconds, and the shortest shutdown time—at normal temperature—is around 180 seconds. Therefore, frequent start-stop cycles may prevent the hydrogen fuel cell from responding promptly.

[0006] Currently, hybrid vehicles often employ the Equivalent Consumption Minimum Strategy (ECMS), a fuel economy-based instantaneous optimization method applicable to hydrogen fuel cell hybrid electric vehicles. However, typical ECMS primarily affects fuel economy by calculating the equivalent hydrogen consumption of the battery power, without adequately addressing the issue of extending the lifespan of the hydrogen fuel cell. This can lead to frequent start-stop cycles, idling, or high-power operation of the hydrogen fuel cell during control, which is detrimental to its lifespan. ECMS strategies limit the power usage range and power change rate, necessitating reasonable control of the hydrogen fuel cell's start-stop operation. Summary of the Invention

[0007] The purpose of this invention is to reduce the number of start-stop cycles of hydrogen fuel cells by optimizing the start-stop control strategy.

[0008] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0009] In a first aspect, the present invention provides a hydrogen fuel cell start-stop control method for a hydrogen fuel cell vehicle, wherein the drive system of the hydrogen fuel cell vehicle includes a hydrogen fuel cell and a power battery, and the method includes:

[0010] Based on the ambient temperature of the hydrogen fuel cell vehicle and the temperature of the hydrogen fuel cell, the estimated start-up time and estimated shutdown time of the hydrogen fuel cell are determined.

[0011] Based on the rated power consumption of the hydrogen fuel cell vehicle and the estimated start-up time, the calculation is performed when the state of charge (SOC) of the power battery drops to the power-limited threshold (SOC). end The current state of charge (SOC) threshold required to start a hydrogen fuel cell FCon ;

[0012] Based on the rated power consumption of the hydrogen fuel cell vehicle, the estimated start-up time of the hydrogen fuel cell, and the estimated shutdown time, the calculation is performed when the SOC of the power battery drops to the power-limited threshold SOC. end The previous SOC threshold for completing one hydrogen fuel cell shutdown and then another hydrogen fuel cell startup was... FCoff ;

[0013] The power battery is in a working state and the state of charge (SOC) of the power battery is at its maximum. FCon and SOC FCoff In between,

[0014] In response to the SOC of the power battery dropping to the SOC FCon Start the hydrogen fuel cell, and

[0015] In response to the SOC of the power battery rising to the SOC FCoff Then, shut down the hydrogen fuel cell.

[0016] Optionally, obtaining the estimated start-up time of the hydrogen fuel cell based on the ambient temperature of the hydrogen fuel cell and the temperature of the hydrogen fuel cell includes:

[0017] The start-up type of the hydrogen fuel cell is determined based on the ambient temperature of the hydrogen fuel cell vehicle and the temperature of the hydrogen fuel cell.

[0018] The estimated start-up time of the hydrogen fuel cell is obtained based on the start-up type of the hydrogen fuel cell;

[0019] The startup types include hot engine startup, cold engine startup, and low-temperature cold startup:

[0020] The formula for calculating the estimated start-up time during hot engine startup is:

[0021] In the formula, △T on1 T represents the estimated start-up time of a hot engine. on1 Indicates the preset warm-up time; k on1 This indicates the preset warm-up start-up time adjustment ratio factor;

[0022] The formula for calculating the estimated start-up time during cold start calculations is as follows:

[0023] In the formula, △T on2 T represents the estimated startup time during cold start-up; on2 Indicates the preset cold start time; k on2 This indicates the preset cold start-up time adjustment ratio factor;

[0024] The formula for calculating the estimated start-up time during a cold start at low temperatures is as follows:

[0025] In the formula, △T on3 This represents the estimated start-up time for a cold start at low temperatures; T on3 Indicates the preset low-temperature chiller start-up time; k on3 This indicates the preset low-temperature chiller start-up time adjustment ratio factor;

[0026] The estimated startup time is determined based on the startup type, which corresponds to ΔT. on1 , △T on2 , △T on3 One of them.

[0027] Optionally, obtaining the estimated shutdown time of the hydrogen fuel cell based on the ambient temperature of the hydrogen fuel cell vehicle and the temperature of the hydrogen fuel cell includes:

[0028] The shutdown type of the hydrogen fuel cell is determined based on the ambient temperature of the hydrogen fuel cell vehicle and the temperature of the hydrogen fuel cell.

[0029] The estimated shutdown duration of the hydrogen fuel cell is obtained based on the shutdown type of the hydrogen fuel cell;

[0030] The shutdown types include normal temperature shutdown and low temperature shutdown;

[0031] The formula for calculating the estimated shutdown time at room temperature is:

[0032] In the formula, △T off1 This represents the estimated shutdown time when the device is turned off at room temperature; T off1 Indicates the preset normal temperature shutdown time; k off1 This indicates the adjustment factor for the preset room temperature shutdown time.

[0033] The formula for calculating the estimated shutdown time during low-temperature shutdown is as follows:

[0034] In the formula, △T off2 This represents the estimated shutdown time during low-temperature shutdown; T off2 Indicates the preset low-temperature shutdown duration; k off2 This indicates the adjustment factor for the preset low-temperature shutdown duration;

[0035] The estimated shutdown duration is determined based on the shutdown type, which corresponds to △T. off1 , △T off2 One of them.

[0036] Optionally, in response to the SOC of the power battery dropping to the SOC FCon Before starting the hydrogen fuel cell, determine the duration ΔT that the hydrogen fuel cell has been shut down while the power battery is operating alone. FCoff Is it greater than or equal to the limit T? FCoff ,

[0037] ;

[0038] If the determination is yes, then the hydrogen fuel cell is started; if the determination is no, then the hydrogen fuel cell is not started.

[0039] Where T FCoff The calculation formula is:

[0040] ;

[0041] In the formula, k T1 This represents the adjustment factor for the preset minimum downtime of the hydrogen fuel cell, where 1.0 ≤ k. T1 ≤2,T off1 This indicates the pre-acquired shutdown time at room temperature.

[0042] Optionally, in response to the SOC of the power battery rising to the SOC FCoff Before shutting down the hydrogen fuel cell, determine the duration ΔT that the hydrogen fuel cell has been operating while the power battery and the hydrogen fuel cell are working together. FCon Is it greater than or equal to T? FCon ,

[0043] ;

[0044] If the determination is yes, then the hydrogen fuel cell is shut down; if the determination is no, then the hydrogen fuel cell is not shut down.

[0045] Where T FCon The calculation formula used is:

[0046] ;

[0047] k T2 This represents the adjustment factor for the preset minimum operating time of the hydrogen fuel cell, 0.9≤k T2 ≤2; This represents the sum of the pre-acquired hot engine start-up time and the normal temperature shutdown time.

[0048] Optionally, the hydrogen fuel cell vehicle has a battery maintenance mode, in which the state of charge (SOC) of the power battery is controlled to fluctuate within a control range. In this battery maintenance mode:

[0049] The SOC FCon The calculation formula is:

[0050] ;

[0051] In the formula, SOC end This indicates the power-limited SOC threshold of the power battery; Q b Indicates the battery charge; V oc Indicates the voltage of the power battery; P d P represents the rated power of the drive system. ac The rated power of the accessory system is indicated by ΔT. The rated power consumption of the hydrogen fuel cell vehicle is the sum of the rated power of the drive system and the rated power of the accessory system. on This represents the estimated startup time.

[0052] The SOCFCoff The calculation formula is:

[0053]

[0054] ;

[0055] In the formula, SOC end This indicates the power-limited SOC threshold of the power battery; Q b Indicates the battery charge; V oc Indicates the voltage of the power battery; P d P represents the rated power of the drive system. ac The rated power of the accessory system is indicated by ΔT. The rated power consumption of the hydrogen fuel cell vehicle is the sum of the rated power of the drive system and the rated power of the accessory system. on This represents the estimated startup time, ΔT. off This represents the estimated shutdown duration.

[0056] Optionally, in battery maintenance mode, the power-limited SOC threshold is... end Based on the pre-obtained temperature and power-limited SOC threshold of the power battery end The relationship curve is obtained.

[0057] Optionally, the hydrogen fuel cell vehicle has a hydrogen hybrid mode, in which the SOC FCon It also depends on the vehicle's average speed when the power battery is working alone. Driving causes the SOC to move along the SOC ref Changing power P s Perform calculations; SOC ref Indicates the reference value for SOC;

[0058] In the hydrogen-mixed mode:

[0059] The SOC FCon The calculation formula is:

[0060] ;

[0061] In the formula, SOC end This indicates the power-limited SOC threshold of the power battery; Q b Indicates the battery charge; V oc Indicates the voltage of the power battery; P d P represents the rated power of the drive system. ac The rated power of the accessory system is indicated by P; the rated power consumption of the hydrogen fuel cell vehicle is the sum of the rated power of the drive system and the rated power of the accessory system. s This indicates that when the power battery is working independently, the vehicle travels at an average speed. Driving causes the SOC to move along the SOC ref Variable power; SOC ref The SOC represents a reference value. ref Changes in cumulative driving mileage of hydrogen fuel cell vehicles; △T on This represents the estimated startup time.

[0062] Wherein, the SOC end The calculation method is as follows:

[0063] Calculate the estimated startup time ΔT on Afterwards, the cumulative driving range of hydrogen fuel cell vehicles , The calculation formula is:

[0064] ;

[0065] In the formula: Indicates average vehicle speed; This represents the cumulative mileage traveled by the vehicle at time t.

[0066] Utilizing SOC ref Calculate the estimated startup time ΔT on The lower limit of the state of charge (SOC) of the power battery after power generation end :

[0067] SOC ref The calculation formula is:

[0068] ;

[0069] SOC ref (t) represents the reference value of SOC at time t; SOC st Indicates the initial state of charge (SOC) under operating conditions; SOC f Indicates the minimum reference limit for SOC; D veh (t) represents the cumulative mileage traveled by the vehicle at time t; D total This represents the expected driving range of the vehicle.

[0070] SOC end The calculation formula is:

[0071]

[0072] ;

[0073] In the formula, Represents t+△T on Reference value for SOC at any given time; Represents t+△T onThe vehicle's cumulative mileage at any given time;

[0074] And, in the hydrogen mixing mode:

[0075] The SOC FCoff The calculation formula is:

[0076] ;

[0077] In the formula, SOC end This indicates the power-limited SOC threshold of the power battery; Q b Indicates the battery charge; V oc Indicates the voltage of the power battery; P d P represents the rated power of the drive system. ac The rated power of the accessory system is indicated; the rated power consumption of the hydrogen fuel cell vehicle is the sum of the rated power of the drive system and the rated power of the accessory system; P s This indicates that when the power battery is working independently, at vehicle speed Make SOC along SOC ref Variable power; SOC ref The SOC represents a reference value. ref △T varies with mileage; on Indicates the estimated startup time; △T off This represents an estimated shutdown duration.

[0078] Wherein, the SOC end The calculation method is as follows:

[0079] Calculate the estimated startup time ΔT on And the estimated shutdown duration △T off Driving range of hydrogen fuel cell vehicles , The calculation formula is:

[0080] ;

[0081] In the formula: Indicates average vehicle speed; This represents the cumulative mileage traveled by the vehicle at time t.

[0082] Utilizing SOC ref Calculate the estimated startup time ΔT on And the estimated shutdown duration △T off Subsequent power battery SOC lower limit end :

[0083] ;

[0084] In the formula, SOCref (t) represents the SOC reference value at time t; SOC st Indicates the initial state of charge (SOC) under operating conditions; SOC f Indicates the minimum reference limit for SOC; D veh (t) represents the cumulative mileage traveled by the vehicle at time t; D total This represents the expected driving range of the vehicle.

[0085]

[0086] ;

[0087] In the formula, Represents t+△T on +△T off The vehicle's cumulative mileage at any given time; Represents t+△T on +△T off SOC reference value at any given time.

[0088] Secondly, the present invention also provides a hydrogen fuel cell start-stop control device for a hydrogen fuel cell vehicle, comprising:

[0089] An estimation module is used to determine the estimated start-up time and estimated shutdown time of the hydrogen fuel cell based on the ambient temperature of the hydrogen fuel cell and the temperature of the hydrogen fuel cell.

[0090] The calculation module is used to calculate the SOC (State of Charge) of the power battery when it drops to the power-limited threshold, based on the rated power consumption of the hydrogen fuel cell vehicle and the estimated start-up time. end The current state of charge (SOC) threshold required to start a hydrogen fuel cell FCon ;

[0091] And based on the rated power consumption of the hydrogen fuel cell vehicle, the estimated start-up time and estimated shutdown time of the hydrogen fuel cell, the calculation is performed when the SOC of the power battery drops to the power-limited threshold SOC. end The previous SOC threshold for completing one hydrogen fuel cell shutdown and then another hydrogen fuel cell startup was... FCoff ;

[0092] A response module is configured to operate when the power battery is in a working state and the state of charge (SOC) of the power battery is at its maximum operating point (SOC). FCon and SOC FCoff Between; in response to the SOC of the power battery dropping to the SOC FCon The hydrogen fuel cell is started, and the state of charge (SOC) of the power battery rises to the specified SOC. FCoff Then, shut down the hydrogen fuel cell.

[0093] Thirdly, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the aforementioned hydrogen fuel cell start-stop control method for a hydrogen fuel cell vehicle.

[0094] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0095] 1. The start-stop method provided by this invention, when applied to the energy management methods of existing hydrogen fuel cell vehicles, can reasonably determine the start-stop timing of the hydrogen fuel cell and, through a threshold SOC (State of Charge)... on and threshold SOC off The setting ensures that the hydrogen fuel cell has enough time to start up before the SOC drops to the point where the power battery's discharge power is limited. This satisfies the vehicle's power requirements without causing large fluctuations in SOC that could lead to frequent start-stop cycles, thus slowing down the hydrogen fuel cell's lifespan degradation rate.

[0096] 2. The hydrogen fuel cell start-stop control method provided by this invention can be directly applied to the energy management methods of existing hydrogen fuel cell vehicles (such as the equivalent minimum hydrogen consumption control strategy ECMS), so that while the energy management method takes the minimum total hydrogen consumption as the control objective for economic factors, it also has a limiting standard for the start-stop control of hydrogen fuel cells, thereby extending the life of hydrogen fuel cells.

[0097] 3. When the hydrogen fuel cell start-stop control method provided by this invention is applied to the energy management methods of existing hydrogen fuel cell vehicles, it can also make the operation of hydrogen fuel cell vehicles under the overall energy management strategy more stable. Because the start-up and shutdown times of hydrogen fuel cells are much longer than those of internal combustion engines, existing energy management strategies lack control standards for the start-stop of hydrogen fuel cells. This results in the power battery operating independently during the shutdown period, and when the driver requests high power, the power battery's SOC may quickly drop to the power-limited threshold SOC. end During this process, the hydrogen fuel cell cannot start up quickly, causing the state of charge (SOC) of the power battery to drop to the power-limited threshold SOC. end Subsequently, the driver's power request may be difficult to meet, which could directly affect the normal operation of the hydrogen fuel cell vehicle. Attached Figure Description

[0098] Figure 1 This is a flowchart illustrating a start-stop control method for a hydrogen fuel cell in a new energy vehicle, as provided in Example 1.

[0099] Figure 2 This is a schematic diagram of the start-stop control principle of a hydrogen fuel cell in Example 1 when applied to the power sustainment (CS) mode of a hydrogen fuel cell vehicle.

[0100] Figure 3 This is a schematic diagram illustrating the start-stop control principle of a hydrogen fuel cell when the start-stop control method of a new energy vehicle in Example 1 is applied to the hydrogen blended mode of a hydrogen fuel cell vehicle. Detailed Implementation

[0101] It should be noted that the technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations on the technical solution of the present invention. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0102] The term "and / or" simply describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Additionally, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0103] Example 1

[0104] Combination Figure 1 This embodiment provides a start-stop control method for hydrogen fuel cells in new energy vehicles. The drive system of the hydrogen fuel cell vehicle includes a hydrogen fuel cell and a power battery. The method includes:

[0105] Step S1: Obtain the estimated start-up time and estimated shutdown time of the hydrogen fuel cell based on the ambient temperature of the hydrogen fuel cell and the temperature of the hydrogen fuel cell.

[0106] Step S1 specifically includes:

[0107] The start-up and shutdown types of the hydrogen fuel cell are determined based on the ambient temperature of the hydrogen fuel cell vehicle and the temperature of the hydrogen fuel cell.

[0108] The estimated start-up time and estimated shutdown time are obtained based on the start-up type and shutdown type of the hydrogen fuel cell;

[0109] The startup types include hot engine startup, cold engine startup, and low-temperature cold startup:

[0110] When the hydrogen fuel cell system is already in operation and at a high temperature, the start-up type is determined to be a hot engine start.

[0111] When a hydrogen fuel cell is started from a non-operational state, and the temperature of the hydrogen fuel cell is low, the start-up type is determined to be a cold start.

[0112] When the ambient temperature is below a preset threshold (e.g., zero degrees Celsius), the startup type is determined to be low-temperature cold start.

[0113] The formula for calculating the estimated start-up time during hot engine startup is as follows:

[0114] (1)

[0115] In the formula, △T on1 T represents the estimated start-up time of a hot engine. on1 Indicates the preset warm-up time; k on1 This indicates the preset warm-up start-up time adjustment ratio factor;

[0116] The formula for calculating the estimated start-up time during cold start-up is as follows:

[0117] (2)

[0118] In the formula, △T on2 T represents the estimated startup time during cold start-up; on2 Indicates the preset cold start time; k on2 This indicates the preset cold start-up time adjustment ratio factor;

[0119] The formula for calculating the estimated start-up time during a cold start at low temperatures is as follows:

[0120] (3)

[0121] In the formula, △T on3 This represents the estimated start-up time for a cold start at low temperatures; T on3 Indicates the preset low-temperature chiller start-up time; k on3 This indicates the preset low-temperature chiller start-up time adjustment ratio factor;

[0122] The estimated startup time ΔT on The determined startup type corresponds to △T. on1 , △T on2 , △T on3 One of them;

[0123] In this embodiment, the heat engine start-up time T on1 The cold start time T is 10 seconds. on2 The cold start time T is 15 seconds. on3The standard value is 480 seconds. For different vehicle applications, the specific data above can be adjusted according to actual conditions. The adjustment factors for warm-up engine start-up time, cold-up engine start-up time, and low-temperature cold-up engine start-up time are all calibrated values, generally taken as greater than 1. Because the start-up times provided by hydrogen fuel cell manufacturers at different temperatures are generally inconsistent with actual vehicle test results, and there may be unconsidered factors interfering, it is necessary to calibrate each proportional factor to ensure the accuracy of the estimated start-up time.

[0124] Different start-up types correspond to different estimated start-up times, which directly affect subsequent start-up and shutdown control. Therefore, it is necessary to determine the start-up type of the hydrogen fuel cell in advance.

[0125] The shutdown types include normal temperature shutdown and low temperature shutdown:

[0126] When shutting down at room temperature, the formula for calculating the estimated shutdown time is:

[0127] (4)

[0128] In the formula, △T off1 This represents the estimated shutdown time when the device is turned off at room temperature; T off1 Indicates the preset normal temperature shutdown time; k off1 This indicates the adjustment factor for the preset normal temperature shutdown time.

[0129] The formula for calculating the estimated shutdown time during low-temperature shutdown is as follows:

[0130] (5)

[0131] In the formula, △T off2 This represents the estimated shutdown time during low-temperature shutdown; T off2 Indicates the preset low-temperature shutdown duration; k off2 This indicates the adjustment factor for the preset low-temperature shutdown duration;

[0132] The estimated shutdown duration △T off The determined shutdown type corresponds to △T. on1 , △T on2 , △T on3 One of them.

[0133] In this embodiment, the shutdown time at normal temperature is 180 seconds, and the shutdown time at low temperature is 400 seconds. This data can be flexibly adjusted according to the application vehicle. Both the normal temperature shutdown time adjustment factor and the low temperature shutdown time adjustment factor are calibrated values, generally taken as greater than 1. Because the start-up times provided by hydrogen fuel cell manufacturers at different temperatures are generally inconsistent with actual vehicle test results, and there may be unconsidered factors interfering, it is necessary to calibrate the normal temperature shutdown time adjustment factor and the low temperature shutdown time adjustment factor to ensure the accuracy of the start-up time estimate. Similarly, different shutdown types correspond to different shutdown time estimates, which will directly affect subsequent start-stop control. Therefore, it is necessary to pre-determine the shutdown type of the hydrogen fuel cell.

[0134] Step S2: Based on the rated power consumption of the hydrogen fuel cell vehicle and the estimated start-up time, calculate the power battery SOC when it drops to the power-limited threshold SOC. end The current state of charge (SOC) threshold required to start a hydrogen fuel cell FCon ;

[0135] And based on the rated power consumption of the hydrogen fuel cell vehicle, the estimated start-up time and estimated shutdown time of the hydrogen fuel cell, the calculation is performed when the State of Charge (SOC) drops to the power-limited threshold. end The previous SOC threshold for completing one hydrogen fuel cell shutdown and then another hydrogen fuel cell startup was... FCoff Among them, the power-limited threshold (SOC) end The settings can be based on the data provided by the manufacturer, or determined based on the actual calibration results.

[0136] Specifically, in this embodiment, the start-stop strategy is as follows: ensuring that the SOC of the power battery does not drop to the power-limited threshold SOC due to the start-stop of the hydrogen fuel cell. end Under the premise of reducing the start-stop frequency of hydrogen fuel cells, the lifespan of hydrogen fuel cells can be extended.

[0137] In step S2, the actual start-stop control method is different for different modes of hydrogen fuel cell vehicles. In this embodiment, the hydrogen fuel cell vehicle has a CD mode (pure electric mode) followed by a CS power maintenance mode and a hydrogen hybrid mode when the hydrogen fuel cell and the power battery work together.

[0138] In this embodiment, the hydrogen fuel cell vehicle operates in hydrogen hybrid mode under normal conditions. If the State of Charge (SOC) decreases too rapidly in hydrogen hybrid mode and approaches the SOC... end It will activate CS mode to maintain SOC stability.

[0139] Combination Figure 2The hydrogen fuel cell vehicle operates in the following mode (Charging of Sustaing, CS phase):

[0140] The SOC of the power battery is controlled to fluctuate within a controlled range. The SOC decreases as the power battery outputs power, while simultaneously being recharged using energy generated beyond the preset power during actual operation of the hydrogen fuel cell and regenerative braking, causing the SOC to rise. Therefore, the SOC of the power battery can be stabilized within the controlled range. In battery sustainment mode, the power-limited SOC threshold is... end Based on the pre-obtained temperature and power-limited SOC threshold of the power battery end The relationship curve can be obtained directly from the table.

[0141] To ensure SOC FCon The SOC is the actual threshold under extreme conditions (power battery simply consuming power). FCon The calculation process assumes that the hydrogen fuel cell does not charge the power battery during startup, and also assumes that the power consumption of the hydrogen fuel cell vehicle reaches the rated power consumption, that is, the power of the drive system and the power of the accessory system both reach the rated power. Furthermore, it is assumed that there is no braking energy recovery during the startup of the hydrogen fuel cell.

[0142] This embodiment calculates the change in SOC using the ampere-hour integration method formula:

[0143] (6)

[0144] (7)

[0145] In the formula, I represents the power battery current; Q b Indicates the battery charge; V oc Indicates the voltage of the power battery; P d P represents the rated power of the drive system. ac Indicates the rated power of the accessory system;

[0146] When the vehicle controller (VCU) is actually running, the integral part of formula (6) is converted into discrete summation to obtain formula (8), and then it can be further converted into formula (9) since the numerator and denominator of the summation term are both constant.

[0147] (8)

[0148] (9)

[0149] In the formula, SOC end This indicates the power-limited SOC threshold of the power battery; Q bIndicates the battery charge; V oc Indicates the voltage of the power battery; P d P represents the rated power of the drive system. ac The rated power of the accessory system is indicated; the rated power consumption of the hydrogen fuel cell vehicle is the sum of the rated power of the drive system and the rated power of the accessory system; △T on This represents the estimated startup time.

[0150] Formula (9) is the final SOC obtained by sorting. FCon The calculation formula.

[0151] Because the shutdown and startup of a hydrogen fuel cell cannot be completed instantaneously, SOC FCoff It is necessary to ensure that the state of charge (SOC) of the power battery is still greater than the state of charge (SOC) when the hydrogen fuel cell is shut down and restarted. end This ensures the vehicle's overall power performance.

[0152] Based on these requirements, this embodiment is based on SOC FCoff In the calculation, it is assumed that the hydrogen fuel cell does not charge the power battery during the period from the start of the energy management strategy requesting the hydrogen fuel cell to the completion of the shutdown. Furthermore, it is assumed that the power battery's energy consumption decreases at its fastest rate in pure electric mode. The minimum SOC of the hydrogen fuel cell under extreme conditions (hydrogen fuel cell solely consuming electricity) is then calculated. FCoff SOC FCOff It can be calculated using the following formula (10).

[0153] The SOC FCoff The formula is:

[0154] (10)

[0155] (11)

[0156] In the formula, SOC end This indicates the power-limited SOC threshold of the power battery; Q b Voc represents the battery charge; Voc represents the battery voltage; P d P represents the rated power of the drive system. ac The rated power of the accessory system is indicated; the rated power consumption of the hydrogen fuel cell vehicle is the sum of the rated power of the drive system and the rated power of the accessory system; △T on This represents the estimated startup time, ΔT. off This represents the estimated shutdown duration.

[0157] Combination Figure 3 The hydrogen fuel cell vehicle operates in the following mode: (Blended range extension control mode)

[0158] In hydrogen hybrid mode, due to the control strategy, the SOC of the power battery is difficult to maintain within a control range, and the corresponding power battery SOC reference value is... ref This represents a decreasing straight line that varies with driving mileage. State of Charge (SOC) in Battery Hold Mode. ref In reality, it's a fixed value, and the SOC fluctuates around this fixed value.

[0159] In hydrogen hybrid mode, the SOC of the power battery will revolve around the SOC. ref Float, and gradually reach SOC FCoff To meet the shutdown conditions of hydrogen fuel cells or reach SOC FCon The conditions for starting a hydrogen fuel cell are met. Therefore, during the operation of a hydrogen fuel cell vehicle, the hydrogen fuel cell will start and shut down at regular intervals.

[0160] In the hydrogen hybrid mode, the SOC of the power battery varies with the driving range of the hydrogen fuel cell vehicle.

[0161] The SOC FCon The calculation formula is:

[0162] (12)

[0163] In the formula, SOC end This indicates the power-limited SOC threshold of the power battery; Q b Voc represents the battery charge; Voc represents the battery voltage; P d P represents the rated power of the drive system. ac The rated power of the accessory system is indicated; the rated power consumption of the hydrogen fuel cell vehicle is the sum of the rated power of the drive system and the rated power of the accessory system; P s This indicates that when the power battery is working alone, the vehicle travels at an average speed. Driving can make the SOC follow the SOC ref Variable power; SOC ref The SOC represents a reference value. ref Changes with mileage; △T on This represents the estimated startup time. The SOC is mentioned here. end The calculation method is as follows:

[0164] Calculate the estimated startup time ΔT on Cumulative driving range of post-hydrogen fuel cell vehicles , △T on Average speed for internal driving distance The estimation is performed using the following formula:

[0165] (13)

[0166] In the formula: Indicates average vehicle speed; This represents the cumulative mileage traveled by the vehicle at time t.

[0167] This embodiment utilizes SOC ref Calculate the estimated startup time ΔT on Subsequent power battery SOC lower limit end ,

[0168] Among them, the SOC reference value varies with mileage. ref The calculation formula is:

[0169] (14)

[0170] In the formula, SOC ref (t) represents the SOC reference value at time t; SOC st Indicates the initial state of charge (SOC) under operating conditions; SOC f Indicates the minimum reference limit for SOC; D veh (t) represents the cumulative mileage traveled by the vehicle at time t; D total This represents the expected driving range of the vehicle.

[0171] (15)

[0172] (16)

[0173] In the formula, For t+△T on The vehicle's cumulative mileage at any given time.

[0174] And, in the hydrogen mixing mode:

[0175] The SOC FCoff The calculation formula is:

[0176] (17)

[0177] In the formula, SOC end This indicates the power-limited SOC threshold of the power battery; Q b Indicates the battery charge; V oc Indicates the voltage of the power battery; P d P represents the rated power of the drive system. ac The rated power of the accessory system is indicated by P; the rated power consumption of the hydrogen fuel cell vehicle is the sum of the rated power of the drive system and the rated power of the accessory system. s This indicates that when the power battery is working independently, at vehicle speed It can make SOC along SOC ref Variable power; SOC ref △T represents a reference value indicating how SOC changes with mileage; on Indicates the estimated startup time; △T off This represents an estimated shutdown duration.

[0178] Wherein, the SOC end The calculation method is as follows:

[0179] Calculate the estimated startup time ΔT on And the estimated shutdown duration △T off Driving range of hydrogen fuel cell vehicles , △T on +△T off Average speed for internal driving distance Make an estimate, The calculation formula is:

[0180] (18)

[0181] In the formula: Indicates average vehicle speed; This represents the cumulative mileage traveled by the vehicle at time t.

[0182] Utilizing SOC ref Calculate the estimated startup time ΔT on And the estimated shutdown duration △T off Subsequent power battery SOC lower limit end :

[0183] (19)

[0184] In the formula, SOC ref (t) represents the SOC reference value at time t; SOC st Indicates the initial state of charge (SOC) under operating conditions; SOC f Indicates the minimum reference limit for SOC; D veh (t) represents the cumulative mileage traveled by the vehicle at time t; D total This represents the expected driving range of the vehicle.

[0185] (20)

[0186] (twenty one)

[0187] In the formula, Represents t+△T on +△T off The vehicle's cumulative mileage at any given time.

[0188] In one specific embodiment, in formulas (12) and (17), the weighted average driving power P based on mileage is used. ds Replaces driving power P d To perform calculations, the P ds The calculation formula is:

[0189] (twenty two)

[0190] In the formula, E1 represents the drive system energy consumption at time t1 corresponding to a travel distance S; E2 represents the drive system energy consumption at time t2 corresponding to a travel distance S; E3 represents the drive system energy consumption at time t3 corresponding to a travel distance S; E4 represents the drive system energy consumption at time t4 corresponding to a travel distance S; k1~k4 represent the mileage power weighting coefficients, satisfying k1+k2+k3+k4 =1, where k1=0.1, k2=0.2, k3=0.4, k4=0.3. The travel distance S = 5~10km.

[0191] Step S3: When the power battery is in the working state and the state of charge (SOC) of the power battery is at its maximum operating state. FCon and SOC FCoff Between; in response to the SOC of the power battery dropping to the SOC FCon The hydrogen fuel cell is started, and the state of charge (SOC) of the power battery rises to the specified SOC. FCoff Then, shut down the hydrogen fuel cell.

[0192] That is, only when the SOC of the power battery meets the threshold SOC FCon Or threshold SOC FCoff Under certain conditions, the hydrogen fuel cell can be started or stopped. When the SOC of the power battery is between two thresholds, the hydrogen fuel cell remains in the started state. This effectively limits the start-up and shutdown of the hydrogen fuel cell based on the SOC reference value, thereby extending the service life of the hydrogen fuel cell.

[0193] Meanwhile, this embodiment uses the threshold SOC FCon and threshold SOC FCoff The calculations ensure that even when the hydrogen fuel cell is shut down, the power battery's state of charge (SOC) will drop to the power-limited threshold SOC. end Previously, the hydrogen fuel cell could also start up promptly, avoiding power limitations when the battery was operating alone, thus meeting the driver's power needs. During the start-up and shutdown of the hydrogen fuel cell, all power requested by the driver was provided by the battery.

[0194] In power maintenance mode or in the hydrogen blending mode, the threshold SOC in step S3 FCon and threshold SOCFCoff The calculation can be performed according to the corresponding calculation method in step S2.

[0195] In a preferred embodiment, to avoid frequent starts of the hydrogen fuel cell, before starting the hydrogen fuel cell, the duration ΔT that the hydrogen fuel cell has been shut down while the power battery is operating alone is determined. FCoff Is it greater than or equal to the limit T? FCoff ,

[0196] (twenty three)

[0197] If the determination is yes, then the hydrogen fuel cell is started; if the determination is no, then the hydrogen fuel cell is not started.

[0198] Where T FCoff The calculation formula is:

[0199] (twenty four)

[0200] In the formula, k T1 This represents the adjustment factor for the minimum downtime of the hydrogen fuel cell, where 1.0 ≤ k. T1 ≤2,T off1 This indicates the pre-acquired shutdown time at room temperature.

[0201] If the vehicle has already reached SOC when it starts end This means determining whether the power battery has the capability to start the hydrogen fuel cell. If it does, the vehicle control system uses the CAN network to request the hydrogen fuel cell controller (FCU) to start the hydrogen fuel cell.

[0202] Meanwhile, to avoid frequent shutdowns of the hydrogen fuel cell, before shutting down the hydrogen fuel cell, the operating time ΔT of the hydrogen fuel cell when the power battery and the hydrogen fuel cell are working together is determined. FCon Is it greater than or equal to T? FCon ,

[0203] (25)

[0204] If the determination is yes, then the hydrogen fuel cell is shut down; if the determination is no, then the hydrogen fuel cell is not shut down.

[0205] Where T FCon The calculation formula used is:

[0206] (26)

[0207] k T2 The minimum operating time adjustment factor for hydrogen fuel cells is 0.9 ≤ k. T2 ≤2; This represents the sum of the pre-acquired hot engine start-up time and the normal temperature shutdown time.

[0208] Example 2

[0209] This embodiment provides an application example of the start-stop control method for hydrogen fuel cell vehicles in Embodiment 1, specifically applied to an energy management method for hydrogen fuel cell electric vehicles, the management method including:

[0210] Step Q1: Calculate the driver's requested power based on the driver control signals collected in real time by the vehicle controller (VCU).

[0211] The vehicle control unit (VCU) collects real-time signals from the driver's accelerator pedal opening, brake pedal opening, brake switch, vehicle speed, and gear position. The torque management module calculates the appropriate drive or braking torque. This torque is then subjected to appropriate low-pass filtering before the smoothed power demand of the driver is calculated (its value is unique at any given time).

[0212] Step Q2: Use the hydrogen fuel cell vehicle start-stop control method described in Example 1 to determine whether the hydrogen fuel cell needs to be started or stopped in the next control cycle.

[0213] Step Q3: If it is determined that the hydrogen fuel cell will be shut down or not started in the next control cycle, the power requested by the driver of the hydrogen fuel cell vehicle will be provided entirely by the power battery. The ECMS optimization algorithm will use the power battery power equal to the power requested by the driver as the control quantity for control.

[0214] or:

[0215] The management method includes:

[0216] Step Q1: Calculate the driver's requested power based on the driver control signals collected in real time by the vehicle controller (VCU).

[0217] The vehicle control unit (VCU) collects real-time signals from the driver's accelerator pedal opening, brake pedal opening, brake switch, vehicle speed, and gear position. The torque management module calculates the appropriate drive or braking torque. This torque is then subjected to appropriate low-pass filtering before the smoothed power demand of the driver is calculated (its value is unique at any given time).

[0218] Step Q2: Use the hydrogen fuel cell vehicle start-stop control method described in Example 1 to determine whether the hydrogen fuel cell needs to be started or stopped in the next control cycle.

[0219] Step Q3: If it is determined that the hydrogen fuel cell will start or not shut down in the next control cycle, the driver's requested power for the hydrogen fuel cell vehicle will be allocated to the power of the power battery and the power of the hydrogen fuel cell.

[0220] Step Q4: Select the minimum and maximum power limit thresholds and the maximum power change rate limit threshold of the hydrogen fuel cell based on the operating status of the hydrogen fuel cell.

[0221] Step Q5: Estimate the feasible hydrogen fuel cell power sequence for the next control cycle based on the minimum and maximum limit thresholds of the hydrogen fuel cell power and the maximum limit threshold of the hydrogen fuel cell power change rate.

[0222] Step Q6: Subtract the hydrogen fuel cell power sequence from the driver's requested power to obtain the preliminary power battery power sequence for the next control cycle. Based on the predetermined feasible power range of the power battery, remove the sequence points in the preliminary power battery power sequence that are outside the power range to obtain the final power battery power sequence and the corresponding final hydrogen fuel cell power sequence.

[0223] The method for determining the feasible power range of the power battery is as follows: The vehicle controller (VCU) of the hydrogen fuel cell receives the total voltage of the power battery, the allowable real-time pulse discharge current limit, the allowable real-time pulse charging current limit, the allowable real-time continuous discharge current limit, and the allowable real-time continuous charging current limit sent by the power battery management system (BMS) in real time through the CAN network. The VCU then calculates the allowable real-time pulse discharge power limit, the allowable real-time pulse charging current power value, the allowable real-time continuous discharge power limit, and the allowable real-time continuous charging power limit. The calculated limits are taken as the feasible power range of the power battery in the hybrid state.

[0224] Step Q7: Calculate the equivalent hydrogen consumption for each power battery in the power battery power sequence and obtain the equivalent hydrogen consumption sequence. Look up the table to obtain the actual hydrogen consumption for each hydrogen fuel cell power in the hydrogen fuel cell power sequence and obtain the actual hydrogen consumption sequence.

[0225] Step Q8: The equivalent hydrogen consumption sequence and the actual hydrogen consumption sequence are added together to form the total hydrogen consumption sequence. The ECMS optimization algorithm selects the hydrogen fuel cell power and power battery power corresponding to the minimum hydrogen consumption in the total hydrogen consumption sequence as control quantities for control.

[0226] The minimum hydrogen consumption (ECMS) control strategy is the most commonly used strategy for power demand allocation in current hydrogen fuel cell vehicles. Based on the above application examples, it can be determined that the start-stop control method in Example 1 can be directly applied to energy management methods, and has broad practical application prospects.

[0227] Example 3

[0228] This embodiment provides a hydrogen fuel cell start-stop control device for a hydrogen fuel cell vehicle, comprising:

[0229] An estimation module is used to determine the estimated start-up time and estimated shutdown time of the hydrogen fuel cell based on the ambient temperature of the hydrogen fuel cell and the temperature of the hydrogen fuel cell.

[0230] The calculation module is used to calculate the SOC (State of Charge) of the power battery when it drops to the power-limited threshold, based on the rated power consumption of the hydrogen fuel cell vehicle and the estimated start-up time. end The current state of charge (SOC) threshold required to start a hydrogen fuel cell FCon ;

[0231] And based on the rated power consumption of the hydrogen fuel cell vehicle, the estimated start-up time and estimated shutdown time of the hydrogen fuel cell, the calculation is performed when the State of Charge (SOC) drops to the power-limited threshold. end The previous SOC threshold for completing one hydrogen fuel cell shutdown and then another hydrogen fuel cell startup was... FCoff ;

[0232] A response module is configured to operate when the power battery is in a working state and the state of charge (SOC) of the power battery is at its maximum operating point (SOC). FCon and SOC FCoff Between: in response to the SOC of the power battery dropping to the SOC FCon The hydrogen fuel cell is started, and the state of charge (SOC) of the power battery rises to the specified SOC. FCoff Then, shut down the hydrogen fuel cell.

[0233] Example 4

[0234] This embodiment provides a computer-readable storage medium storing a computer program thereon. When the computer program is executed by a processor, it implements the hydrogen fuel cell start-stop control method for a hydrogen fuel cell vehicle as described in Embodiment 1.

[0235] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0236] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0237] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0238] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0239] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A method for starting and stopping a hydrogen fuel cell in a hydrogen fuel cell vehicle, the hydrogen fuel cell vehicle comprising a hydrogen fuel cell and a power battery; characterized in that: The method includes: Based on the ambient temperature of the hydrogen fuel cell vehicle and the temperature of the hydrogen fuel cell, the estimated start-up time and estimated shutdown time of the hydrogen fuel cell are determined. Based on the rated power consumption of the hydrogen fuel cell vehicle and the estimated start-up time, the calculation is performed when the state of charge (SOC) of the power battery drops to the power-limited threshold (SOC). end The current state of charge (SOC) threshold required to start a hydrogen fuel cell FCon ; Based on the rated power consumption of the hydrogen fuel cell vehicle, the estimated start-up time of the hydrogen fuel cell, and the estimated shutdown time, the calculation is performed when the SOC of the power battery drops to the power-limited threshold SOC. end The previous SOC threshold for completing one hydrogen fuel cell shutdown and then another hydrogen fuel cell startup was... FCoff ; The power battery is in a working state and the state of charge (SOC) of the power battery is at its maximum. FCon and SOC FCoff In between, In response to the SOC of the power battery dropping to the SOC FCon Start the hydrogen fuel cell, and In response to the SOC of the power battery rising to the SOC FCoff Then, shut down the hydrogen fuel cell.

2. The hydrogen fuel cell start-stop control method for hydrogen fuel cell vehicles according to claim 1, characterized in that: The process of obtaining the estimated start-up time of the hydrogen fuel cell based on the ambient temperature of the hydrogen fuel cell vehicle and the temperature of the hydrogen fuel cell includes: The start-up type of the hydrogen fuel cell is determined based on the ambient temperature of the hydrogen fuel cell vehicle and the temperature of the hydrogen fuel cell. The estimated start-up time of the hydrogen fuel cell is obtained based on the start-up type of the hydrogen fuel cell; The startup types include hot engine startup, cold engine startup, and low-temperature cold startup: The formula for calculating the estimated start-up time during hot engine startup is: In the formula, △T on1 T represents the estimated start-up time of a hot engine. on1 Indicates the preset warm-up time; k on1 This indicates the preset warm-up start-up time adjustment ratio factor; The formula for calculating the estimated start-up time during cold start is: In the formula, △T on2 T represents the estimated startup time during cold start-up; on2 Indicates the preset cold start time; k on2 This indicates the preset cold start-up time adjustment ratio factor; The formula for calculating the estimated start-up time during a cold start at low temperatures is as follows: In the formula, △T on3 This represents the estimated start-up time for a cold start at low temperatures; T on3 Indicates the preset low-temperature chiller start-up time; k on3 This indicates the preset low-temperature chiller start-up time adjustment ratio factor; The estimated startup time is determined based on the startup type, which corresponds to ΔT. on1 , △T on2 , △T on3 One of them.

3. The hydrogen fuel cell start-stop control method for hydrogen fuel cell vehicles according to claim 2, characterized in that: The estimated shutdown time of the hydrogen fuel cell, obtained based on the ambient temperature of the hydrogen fuel cell vehicle and the temperature of the hydrogen fuel cell, includes: The shutdown type of the hydrogen fuel cell is determined based on the ambient temperature of the hydrogen fuel cell vehicle and the temperature of the hydrogen fuel cell. The estimated shutdown duration of the hydrogen fuel cell is obtained based on the shutdown type of the hydrogen fuel cell; The shutdown types include normal temperature shutdown and low temperature shutdown; The formula for calculating the estimated shutdown time at room temperature is: In the formula, △T off1 This represents the estimated shutdown time when the device is turned off at room temperature; T off1 Indicates the preset normal temperature shutdown time; k off1 This indicates the adjustment factor for the preset room temperature shutdown time. The formula for calculating the estimated shutdown time during low-temperature shutdown is as follows: In the formula, △T off2 This represents the estimated shutdown time during low-temperature shutdown; T off2 Indicates the preset low-temperature shutdown duration; k off2 This indicates the adjustment factor for the preset low-temperature shutdown duration; The estimated shutdown duration is determined based on the shutdown type, which corresponds to △T. off1 , △T off2 One of them.

4. The hydrogen fuel cell start-stop control method for hydrogen fuel cell vehicles according to claim 1, characterized in that: In response to the SOC of the power battery dropping to the SOC FCon Before starting the hydrogen fuel cell, determine the duration ΔT that the hydrogen fuel cell has been shut down while the power battery is operating alone. FCoff Is it greater than or equal to the limit T? FCoff , If the determination is yes, then the hydrogen fuel cell is started; if the determination is no, then the hydrogen fuel cell is not started. Where T FCoff The calculation formula is: In the formula, k T1 This represents the preset adjustment factor for the minimum downtime of the hydrogen fuel cell, where 1.0 ≤ k. T1 ≤2,T off1 This indicates the pre-acquired shutdown time at room temperature.

5. The hydrogen fuel cell start-stop control method for hydrogen fuel cell vehicles according to claim 1, characterized in that: In response to the rise of the SOC of the power battery to the SOC FCoff Before shutting down the hydrogen fuel cell, determine the duration ΔT that the hydrogen fuel cell has been operating while the power battery and the hydrogen fuel cell are working together. FCon Is it greater than or equal to T? FCon , If the determination is yes, then the hydrogen fuel cell is shut down; if the determination is no, then the hydrogen fuel cell is not shut down. Where T FCon The calculation formula used is: ;k T2 This represents the preset minimum operating time adjustment factor for the hydrogen fuel cell, 0.9≤k T2 ≤2; This represents the sum of the pre-acquired hot engine start-up time and the normal temperature shutdown time.

6. The hydrogen fuel cell start-stop control method for hydrogen fuel cell vehicles according to claim 1, characterized in that: The hydrogen fuel cell vehicle has a battery maintenance mode, in which the state of charge (SOC) of the power battery is controlled to fluctuate within a control range. In this battery maintenance mode: The SOC FCon The calculation formula is: In the formula, SOC end This indicates the power-limited SOC threshold of the power battery; Q b Indicates the battery charge; V oc Indicates the voltage of the power battery; P d P represents the rated power of the drive system. ac The rated power of the accessory system is indicated by ΔT. The rated power consumption of the hydrogen fuel cell vehicle is the sum of the rated power of the drive system and the rated power of the accessory system. on This represents the estimated startup time. The SOC FCoff The calculation formula is: In the formula, SOC end This indicates the power-limited SOC threshold of the power battery; Q b Indicates the battery charge; V oc Indicates the voltage of the power battery; P d P represents the rated power of the drive system. ac The rated power of the accessory system is indicated by ΔT. The rated power consumption of the hydrogen fuel cell vehicle is the sum of the rated power of the drive system and the rated power of the accessory system. on This represents the estimated startup time, ΔT. off This represents the estimated shutdown duration.

7. The hydrogen fuel cell start-stop control method for hydrogen fuel cell vehicles according to claim 6, characterized in that: In battery sustain mode, the power-limited SOC threshold (SOC) end Based on the pre-obtained temperature and power-limited SOC threshold of the power battery end The relationship curve was obtained.

8. The hydrogen fuel cell start-stop control method for hydrogen fuel cell vehicles according to claim 1, characterized in that: The hydrogen fuel cell vehicle has a hydrogen hybrid mode, in which the SOC of the power battery changes with the driving range of the hydrogen fuel cell vehicle. In the hydrogen-mixed mode: The SOC FCon The calculation formula is: In the formula, SOC end This indicates the power-limited SOC threshold of the power battery; Q b Indicates the battery charge; V oc Indicates the voltage of the power battery; P d P represents the rated power of the drive system. ac The rated power of the accessory system is indicated by P; the rated power consumption of the hydrogen fuel cell vehicle is the sum of the rated power of the drive system and the rated power of the accessory system. s This indicates that when the power battery is working independently, the vehicle travels at an average speed. Driving causes the SOC to move along the SOC ref Variable power; SOC ref The SOC represents a reference value. ref Changes in cumulative driving mileage of hydrogen fuel cell vehicles; △T on This represents the estimated startup time. Wherein, the SOC end The calculation method is as follows: Calculate the estimated startup time ΔT on Afterwards, the cumulative driving range of hydrogen fuel cell vehicles , The calculation formula is: In the formula: Indicates average vehicle speed; This represents the cumulative mileage traveled by the vehicle at time t. Utilizing SOC ref Calculate the estimated startup time ΔT on Subsequent power battery SOC lower limit end : SOC ref The calculation formula is: In the formula, SOC ref (t) represents the reference value of SOC at time t; SOC st Indicates the initial state of charge (SOC) under operating conditions; SOC f Indicates the minimum reference limit for SOC; D veh (t) represents the cumulative mileage traveled by the vehicle at time t; D total This represents the expected driving range of the vehicle. SOC end The calculation formula is: ； In the formula, Represents t+△T on Reference value for SOC at any given time; Represents t+△T on The vehicle's cumulative mileage at any given time; And, in the hydrogen mixing mode: The SOC FCoff The calculation formula is: In the formula, SOC end This indicates the power-limited SOC threshold of the power battery; Q b Indicates the battery charge; V oc Indicates the voltage of the power battery; P d P represents the rated power of the drive system. ac The rated power of the accessory system is indicated; the rated power consumption of the hydrogen fuel cell vehicle is the sum of the rated power of the drive system and the rated power of the accessory system; P s This indicates that when the power battery is working independently, at vehicle speed Make SOC along SOC ref Variable power; SOC ref The SOC represents a reference value. ref △T varies with mileage; on Indicates the estimated startup time; △T off This represents an estimated shutdown duration. Wherein, the SOC end The calculation method is as follows: Calculate the estimated startup time ΔT on And the estimated shutdown duration △T off Driving range of hydrogen fuel cell vehicles , The calculation formula is: In the formula: Indicates average vehicle speed; This represents the cumulative mileage traveled by the vehicle at time t. Utilizing SOC ref Calculate the estimated startup time ΔT on And the estimated shutdown duration △T off Subsequent power battery SOC lower limit end : In the formula, SOC ref (t) represents the SOC reference value at time t; SOC st Indicates the initial state of charge (SOC) under operating conditions; SOC f Indicates the minimum reference limit for SOC; D veh (t) represents the cumulative mileage traveled by the vehicle at time t; D total This represents the expected driving range of the vehicle. ； In the formula, Represents t+△T on +△T off The vehicle's cumulative mileage at any given time; Represents t+△T on +△T off SOC reference value at any given time.

9. A start-stop control device for a hydrogen fuel cell vehicle, characterized in that: include: An estimation module is used to determine the estimated start-up time and estimated shutdown time of the hydrogen fuel cell based on the ambient temperature of the hydrogen fuel cell and the temperature of the hydrogen fuel cell. The calculation module is used to calculate the SOC (State of Charge) of the power battery when it drops to the power-limited threshold, based on the rated power consumption of the hydrogen fuel cell vehicle and the estimated start-up time. end The current state of charge (SOC) threshold required to start a hydrogen fuel cell FCon ; And based on the rated power consumption of the hydrogen fuel cell vehicle, the estimated start-up time and estimated shutdown time of the hydrogen fuel cell, the calculation is performed when the SOC of the power battery drops to the power-limited threshold SOC. end The previous SOC threshold for completing one hydrogen fuel cell shutdown and then another hydrogen fuel cell startup was... FCoff ; A response module is configured to operate when the power battery is in a working state and the state of charge (SOC) of the power battery is at its maximum operating point (SOC). FCon and SOC FCoff Between; in response to the SOC of the power battery dropping to the SOC FCon The hydrogen fuel cell is started, and the state of charge (SOC) of the power battery rises to the specified SOC. FCoff Then, shut down the hydrogen fuel cell.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements a hydrogen fuel cell start-stop control method for a hydrogen fuel cell vehicle as described in any one of claims 1-8.

Images