CN102167036B - Control method of fuel cell hybrid vehicle - Google Patents

Abstract

The invention relates to a fuel cell hybrid vehicle control method, the steps are as follows: 1) a motor state switching module, a driver command interpretation module, a power battery charge state verification module, a road condition self-adaptive compensation module, Vehicle diagnostic correction module and equivalent hydrogen consumption optimization distribution module; 2) The vehicle controller reads the gear signal, pedal signal and TTCAN bus data; 3) The motor state switching module switches the motor state; 4) The driver command interpretation module determines Motor target torque; 5) SOC value, TTCAN bus voltage, and power battery current are verified by the power battery state-of-charge verification module; 6) Road condition adaptive compensation module calculates vehicle auxiliary power and DC/DC dynamic compensation time constant; 7) The vehicle diagnosis and correction module corrects the motor target torque and DC/DC target current; 8) In the equivalent hydrogen consumption optimization distribution module, the vehicle target power is optimally allocated between the power battery and the fuel cell; 9) The corrected The motor target torque and the DC/DC target current are sent to the motor controller and the DC/DC controller to realize the output power control of the motor and the fuel cell.

Description

A control method for a fuel cell hybrid electric vehicle

technical field

The invention relates to a vehicle control method, in particular to a fuel cell hybrid vehicle control method for general urban working conditions.

Background technique

Lack of petroleum resources and environmental pollution are major concerns of governments, scientific research institutions and multinational corporations, and many governments and corporations invest a lot of resources in researching technical solutions to this problem. Fuel cells (or proton exchange membrane fuel cells) rely on the chemical reaction of hydrogen and oxygen to generate electricity and water, with low noise and no pollution, so they are considered to be an important technical solution to resource and environmental problems.

Currently, fuel cells are mainly used in fuel cell hybrid vehicles. Fuel cell hybrid vehicles generally adopt the configuration of fuel cell plus power battery or super capacitor. The power battery (or super capacitor) provides overload power during loading to avoid sudden changes in the working conditions of the fuel cell; when braking, the power battery (or super capacitor) absorbs part of the braking energy to improve system economy. The fuel cell hybrid power system includes multiple power sources (such as fuel cell power source and power battery power source), and the vehicle controller controls the multiple power sources to work.

With regard to the hybrid configuration of fuel cell hybrid electric vehicles, the prior art provides an "energy type" hybrid power system. As shown in Figure 1 (the thin solid line in the figure represents the high-voltage connection, and the thick solid line represents the mechanical connection), in this configuration, the fuel cell system passes through a DC/DC converter (Direct Current to Direct Current converter, DC/DC) It is connected in parallel with the power battery, and then converted to AC to drive the three-phase asynchronous motor through a DC/AC inverter (Direct Current to Alternating Current inverter, DC/AC). Various vehicle control methods for fuel cell hybrid electric vehicles are also provided in the prior art, including rule-based vehicle control methods, instantaneous optimization, global optimization, and braking energy feedback vehicle control methods, etc., but there is no general-purpose Vehicle control method for urban working conditions.

Contents of the invention

In view of the above problems, the object of the present invention is to provide a fuel cell hybrid vehicle control method that can solve urban working conditions with low average speed, high proportion of acceleration and deceleration conditions, and large braking energy consumption.

In order to achieve the above object, the present invention adopts the following technical solutions: a fuel cell hybrid vehicle control method, including the following steps: 1) setting a motor state switching module, a driver command interpretation module, and a power battery charging module in the vehicle controller; State verification module, road condition self-adaptive compensation module, vehicle diagnosis and correction module, and equivalent hydrogen consumption optimization distribution module, wherein TTCAN is a time-triggered controller local area network; and TTCAN communication port to read the driver gear signal, driver pedal signal and TTCAN bus communication data; , reversing”; 4) The driver command interpretation module determines the motor state according to the motor state signal set by the motor state switching module, and then determines the target torque of the motor; 5) The power battery state of charge verification module The SOC value sent by the power battery management system, as well as the TTCAN bus voltage and the power battery current are verified, wherein the SOC value is the power battery state-of-charge verification value; 6) The road condition adaptive compensation module is based on the received component status information , online calculation of vehicle auxiliary power P _aux , DC/DC dynamic compensation time constant τ _dc , and compensation and adaptive adjustment of power battery SOC value and fuel cell performance degradation; 7) The vehicle diagnosis and correction module according to each component 8) In the equivalent hydrogen consumption optimization distribution module, the target power of the whole vehicle is optimally distributed between the power battery and the fuel cell, so that the system is equivalent The hydrogen consumption is minimized and the SOC value is kept balanced; 9) The vehicle controller sends the corrected motor target torque and DC/DC target current to the motor controller and DC/DC controller respectively through the TTCAN bus to realize the control of the motor and Output power control of fuel cells.

In the step 3), the switching steps of the motor state switching module are as follows: ① judge whether the driver’s gear signal is neutral, if so, set the motor state to idle, otherwise enter the next step; ② judge whether the gear signal is Reverse gear, if it is, set the state of the motor to reverse; otherwise, go to the next step; ③Judge whether the brake pedal is greater than the braking threshold, if yes, set the state of the motor to brake; otherwise, go to the next step; ④Judge the brake pedal Whether it is less than or equal to the braking threshold, and the accelerator pedal is greater than the acceleration threshold, if yes, set the motor state to driving, otherwise, set the motor state to coasting.

上式中α为司机踏板位置信号，取值范围0～1；T_qd,max为电机最大驱动转矩，根据电机在驱动状态下的外特性曲线及目标转矩关系图，得到驱动目标转矩

的值；所述司机命令解释模块确定电机在制动状态下时，则电机目标转矩为制动目标转矩

上式中γ为制动踏板系数，T_qb,max为最大制动转矩，根据电机在制动状态下的外特性曲线及目标转矩关系图，得到制动目标转矩

的值。In the step 4), when the driver command interpretation module determines that the motor is in the state of idling, reversing, driving and coasting, the motor target torque is the driving target torque

In the above formula, α is the position signal of the driver’s pedal, and the value range is 0 to 1; T _qd,max is the maximum driving torque of the motor. According to the external characteristic curve and the target torque relationship diagram of the motor in the driving state, the driving target torque can be obtained

When the driver command interpretation module determines that the motor is in the braking state, the motor target torque is the braking target torque

In the above formula, γ is the coefficient of the brake pedal, and T _qb,max is the maximum braking torque. According to the external characteristic curve and the target torque relationship diagram of the motor in the braking state, the braking target torque can be obtained

value.

The brake pedal coefficient γ, when adopting the series braking energy feedback strategy, the brake pedal coefficient γ can be obtained by the following formula: γ=4(β-β ₁ )(β-β ₂ )(β ₁ - β ₂ ) ^-2 , in the above formula, β is the brake pedal position signal, β ₁ and β ₂ are the parameters of the brake feedback strategy, which affect the braking effect of the vehicle, and are calibrated according to the actual situation.

In the step 5), the verification process of the power battery state of charge verification module is as follows: ① Use the least squares recursive algorithm to estimate the current power battery open circuit voltage and average charge and discharge internal resistance online, and combine the power battery open circuit The voltage-SOC curve and the charge-discharge internal resistance-SOC curve reversely deduce the SOC value; ②according to the SOC value sent by the power battery management system, combined with the power battery open-circuit voltage-SOC curve and the charge-discharge internal resistance-SOC curve, the power battery open circuit is calculated Voltage and average charge and discharge internal resistance; ③Based on the open circuit voltage, average charge and discharge internal resistance calculated in step ②, and the SOC value sent by the power battery management system, calculate the open circuit voltage and average charge and discharge Internal resistance, and the relative error of the SOC value; ④ If the relative error of the three parameter values is less than 10%, the power battery state of charge verification module determines that the SOC value sent by the power battery management system is credible, otherwise the power battery charge The power state verification module uses the estimated SOC value obtained in step ① to replace the SOC value sent by the power battery management system.

In the step 6), in the road condition adaptive compensation module, the auxiliary power P _aux of the vehicle is estimated online by using a first-order low-pass filter algorithm according to the TTCAN bus data:

${\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; aux</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; bat</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; in</span>}}}{{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; aux</span>}}\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; ,</span>$

In the above formula, P _dc is the DC/DC output power, P _bat is the power battery output power, P _m,in is the motor input power, all of which can be read from the TTCAN bus data, τ _aux is the filter constant, and s is the complex number of the transfer function variable; the DC/DC dynamic compensation time constant τ _dc is calculated as follows: τ _dc = λ ₁ Δτ _dc1 + λ ₂ Δτ _dc2 + λ ₃ Δτ _dc3 +τ _dc0 , where λ ₁ , λ ₂ , λ ₃ is the weighting coefficient of fuel cell performance degradation: λ ₁ =0.4, λ ₂ =0.4, λ ₃ =0.2, τ _dc0 =5s, Δτ _dc1 , Δτ _dc2 and Δτ _dc3 are the three-parameter open circuit voltage U ₀ according to the fuel cell system UI curve , the correction value determined by the ohmic internal resistance R _fc and the concentration polarization parameter b, Δτ _dc1 , Δτ _dc2 and Δτ _dc3 change with the performance degradation of the fuel cell stack.

In the step 9), the corrected calculation formulas of the motor target torque and DC/DC target current are as follows:

$\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; mod</span>}\mathrm{<span\; class="notranslate">\; identified</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&Delta;I</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; mod</span>}\mathrm{<span\; class="notranslate">\; identified</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&Delta;I</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; mod</span>}\mathrm{<span\; class="notranslate">\; identified</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}^{<span\; class="notranslate">\; *</span>}\\ {\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; mod</span>}\mathrm{<span\; class="notranslate">\; identified</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&Delta;T</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; mod</span>}\mathrm{<span\; class="notranslate">\; identified</span>}}^{<span\; class="notranslate">\; *</span>}\end{array}\right.<span\; class="notranslate">\; ,</span>$

为电机目标转矩，

为电机目标转矩诊断修正值，

为未经修正的DC/DC目标电流，

为考虑动力电池SOC值平衡的DC/DC目标电流修正值，

为DC/DC目标电流诊断修正值，

为驱动电机目标转矩诊断修正值。In the above formula

is the motor target torque,

is the motor target torque diagnosis correction value,

is the uncorrected DC/DC target current,

In order to consider the DC/DC target current correction value of the power battery SOC value balance,

is the DC/DC target current diagnostic correction value,

Diagnostic correction value for the target torque of the drive motor.

Due to the adoption of the above technical solutions, the present invention has the following advantages: 1. The present invention considers system economy, fuel cell durability and vehicle safety, and solves the problem of energy management in urban working conditions. 2. The present invention provides a comprehensive energy management method for a fuel cell hybrid electric bus. The vehicle controller determines the motor target torque and DC/DC target current, transfer motor target torque and DC/DC target current to TTCAN bus. 3. The present invention can optimize the system economy under urban working conditions, ensure the SOC balance of the power battery, prolong the service life of the fuel cell as much as possible, and ensure the safety of the whole vehicle. The fuel cell city bus using the present invention has successfully carried out Olympic demonstration and Beijing public transport demonstration operation, reaching domestic first-class and international advanced level, so it can be widely used in the control application of fuel cell hybrid vehicles.

Description of drawings

Fig. 1 is a control schematic diagram in the prior art

Fig. 2 is a schematic diagram of the composition of the vehicle controller of the present invention

Fig. 3 is a flow chart of the work of the vehicle controller of the present invention

Fig. 4 is the working flow diagram of the motor state switching module of the present invention

Fig. 5 is a schematic diagram of the state switching relationship of the motor of the present invention

Fig. 6 is the working flow chart of driver's command interpretation module of the present invention

Fig. 7 is the relationship diagram between the external characteristic curve and the motor braking target torque of the motor in the driving state of the present invention

Fig. 8 is the external characteristic curve and the target torque relationship diagram of the motor of the present invention under the braking state

Fig. 9 is a working flow diagram of the SOC verification module of the present invention

Fig. 10 is a working flow diagram of the road condition adaptive compensation module of the present invention

Fig. 11 is the relationship diagram of the present invention's dynamic compensation time constant Δτ _dc and three parameters

Fig. 12 is a working flow diagram of the whole vehicle diagnosis and correction module of the present invention

Fig. 13 is a block diagram of the vehicle diagnosis correction algorithm of the present invention

Figure 14 is a work flow diagram of the equivalent hydrogen consumption optimization distribution module of the present invention

Fig. 15 is a graph of the relationship between the optimal power of the power battery and the SOC when the power battery SOC balance correction coefficient μ=0.6 in the present invention

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

As shown in Figure 2 and Figure 3, the vehicle controller of the present invention includes a motor state switching module, a driver command interpretation module, a SOC (State of Charge, power battery state of charge) verification module, a road condition adaptive compensation module, The vehicle diagnosis and correction module and the equivalent hydrogen consumption optimization distribution module also have interfaces such as digital ports, analog ports, and TTCAN communication ports. The SOC, bus voltage, power battery current and other signals in the figure are measured and calculated by the BMS (Battery Management System, power battery management system) in the existing equipment, and then sent to the TTCAN (Time Triggered Controller Area Network, time-triggered control device local area network) bus; the motor speed signal is measured and calculated by the motor controller in the existing equipment, and sent to the TTCAN bus; the component status information is managed by each component controller (motor controller, DC/DC controller, power battery) system, fuel cell controller, etc.) after measurement and calculation, it is sent to the TTCAN bus.

Vehicle control method of the present invention comprises the following steps:

1. Read data

The vehicle controller reads the driver's gear signal, driver's pedal signal and TTCAN bus communication data from the digital quantity, analog quantity and TTCAN communication port. For example, the vehicle controller reads the driver's gear signal from the digital port, reads the driver's pedal signal from the analog port, and reads the TTCAN bus communication data from the TTCAN communication port. In addition, according to the needs of different systems, the vehicle controller can also read signals from leakage sensors, brake pressure sensors, etc. Signal.

2. Motor state switching

As shown in Figure 4 and Figure 5, the motor state switching module of the vehicle controller switches the motor state between "driving, idling, coasting, braking, and reversing" according to the driver's gear signal and the driver's pedal signal.

For example: the vehicle controller first judges whether the driver’s gear signal is neutral, and if so, sets the motor state to idle speed; otherwise, further judges whether the gear signal is reverse gear, and if so, sets the motor state to reverse; otherwise, Further judge whether the brake pedal is greater than the braking threshold, if so, set the motor state to brake; otherwise, further judge whether the brake pedal is less than or equal to the braking threshold, and the accelerator pedal is greater than the acceleration threshold, if yes, set the motor state to drive, otherwise, set the motor state to coast.

3. Driver command explanation

As shown in Figure 2 and Figure 6, the driver command interpretation module determines whether the motor state is a braking state according to the motor state signal set by the motor state switching module, and if it is not a braking state, it is "idle speed", "reversing", "driving" or "sliding" state, at this time the target torque of the motor is the driving target torque

${\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; qd</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; \&alpha;T</span>}}_{\mathrm{<span\; class="notranslate">\; qd</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

的对应关系图，根据式（1）以及图7所示对应关系，可以得到驱动目标转矩

的值。In formula (1), α is the driver’s pedal position signal, and its value ranges from 0 to 1; T _qd,max is the maximum driving torque of the motor, as shown in Figure 7, which is the maximum driving torque T _qd,max in the driving state and the motor Speed n and motor drive target torque

According to the corresponding relationship diagram of , according to formula (1) and the corresponding relationship shown in Figure 7, the driving target torque can be obtained

value.

As shown in Figure 6, if it is in the braking state, the motor target torque at this time is the motor braking target torque

${\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; qb</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; qb</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; max</span>}}\mathrm{<span\; class="notranslate">\; \&gamma;</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

的对应关系图。In formula (2), T _qb,max is the maximum braking torque, as shown in Figure 8, it is the maximum braking torque T _qb,max of the motor in the braking state, the motor speed n and the motor braking target torque

The corresponding relationship diagram.

In formula (2), γ is the brake pedal coefficient. When the braking energy feedback strategy is not adopted, γ=0; when the series braking energy feedback strategy is adopted, γ is obtained by the following formula:

γ=4(β-β ₁ )(β-β ₂ )(β ₁ -β ₂ ) ^-2 , (3)

In formula (3), β is the position signal of the brake pedal, and β ₁ and β ₂ are the parameters of the brake feedback strategy. This parameter affects the braking effect of the vehicle and is calibrated according to the actual situation.

4. SOC verification

As shown in Figure 2 and Figure 9, the SOC verification module verifies the SOC value sent by the BMS, as well as the TTCAN bus voltage and power battery current. The verification process is as follows:

1) According to the charge and discharge current and voltage signals of the power battery, use RLS (Recursive Least Squares Algorithm, the least squares recursive algorithm) to estimate the current power battery open circuit voltage and average charge and discharge internal resistance online, and combine the power battery open circuit voltage-SOC curve and Charge and discharge internal resistance-SOC curve reverses the SOC value. Among them, the average charging and discharging internal resistance refers to the average value of the charging internal resistance and discharging internal resistance of the power battery under a certain SOC.

2) According to the SOC value sent by the BMS, combined with the open-circuit voltage-SOC curve of the power battery and the charge-discharge internal resistance-SOC curve, the open-circuit voltage and the average charge-discharge internal resistance of the power battery are calculated.

3) Calculate the relative open circuit voltage, average charge and discharge internal resistance, and SOC value estimated in step 1) based on the calculated open circuit voltage, average charge and discharge internal resistance, and SOC value sent by the BMS in step 2). error.

4) If the calculated relative errors of the open circuit voltage, average charge and discharge internal resistance, and the SOC value sent by the BMS are all less than 10%, the SOC verification module determines that the SOC value sent by the BMS is credible, otherwise the SOC calibration The verification module uses the estimated SOC value obtained in step 1) to replace the SOC value sent by the BMS; the determined SOC value is transmitted from the SOC verification module to the equivalent hydrogen consumption optimization distribution module.

5. Road Condition Adaptive Compensation

As shown in Figure 10, the road condition adaptive compensation module calculates the vehicle auxiliary power P _aux and DC/DC dynamic compensation time constant τ _dc online according to the received component status information, and performs corresponding calculations on the power battery SOC value and fuel cell performance degradation. Compensation and adaptive adjustment.

Among them, the auxiliary power P _aux of the vehicle can be estimated online by using the first-order low-pass filter algorithm according to the TTCAN bus data:

${\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; aux</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; bat</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; in</span>}}}{{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; aux</span>}}\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

In formula (4), P _dc is the DC/DC output power, P _bat is the power battery output power, P _m,in is the motor input power, all of which can be read from the TTCAN bus data, and τ _aux is the filter constant. s is the complex variable of the transfer function.

After that, the data is read from the TTCAN bus, and the least squares online recursive algorithm is used to estimate the three parameters of the fuel cell UI curve U ₀ (open circuit voltage), R _fc (ohmic internal resistance) and b (concentration polarization parameter). According to the curve shown in FIG. 11 , the values corresponding to Δτ _dc1 , Δτ _dc2 and Δτ _dc3 are calculated. Among them, Δτ _dc1 , Δτ _dc2 and Δτ _dc3 are the correction values determined according to the three parameters U ₀ , R _fc and b of the fuel cell UI curve respectively. As the performance of the fuel cell stack declines, the DC/DC dynamic compensation time constant becomes larger, In order to make the output power of the electric stack change more slowly, thereby protecting the fuel cell. Therefore, Δτ _dc1 decreases with U ₀ , Δτ _dc2 increases with R _fc , and Δτ _dc3 increases with b. Then, calculate the DC/DC dynamic compensation time constant τ _dc according to the following formula:

τ _dc = λ ₁ Δτ _dc1 + λ ₂ Δτ _dc2 + λ ₃ Δτ _dc3 + τ _dc0 , (5)

In formula (5), λ ₁ , λ ₂ , λ ₃ are the weighting coefficients of fuel cell performance degradation: λ ₁ =0.4, λ ₂ =0.4, λ ₃ =0.2. τ _dc0 =5s. DC/DC target current correction value considering power battery SOC balance Calculate according to the formula:

${\mathrm{<span\; class="notranslate">\; \&Delta;I</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; mod</span>}\mathrm{<span\; class="notranslate">\; identified</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; k</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; mb</span>}}^{<span\; class="notranslate">\; *</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; ocv</span>}}\mathrm{<span\; class="notranslate">\; Qs</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

为电机制动功率（取绝对值），η_m为电机效率，s为传递函数的复数变量，U_ocv为动力电池端电压。通过式（6），当整车制动能量通过电机回收至动力电池时，燃料电池输出功率相应减小一部分，从而防止动力电池SOC过高。In formula (6), Q is the capacity of the power battery, k is the slope of the intersection of the optimal power-SOC curve of the power battery and the x-axis, K _p is the correction coefficient, and the value is between 1 and 1.5.

is the braking power of the motor (take the absolute value), η _m is the efficiency of the motor, s is the complex variable of the transfer function, and U _ocv is the terminal voltage of the power battery. According to formula (6), when the braking energy of the whole vehicle is recovered to the power battery through the motor, the output power of the fuel cell is correspondingly reduced to prevent the SOC of the power battery from being too high.

6. Vehicle diagnosis and correction

和DC/DC目标电流诊断修正值

图中各变量意义为：As shown in Figure 12, the vehicle diagnosis and correction module corrects the motor target torque and DC/DC target current according to the limitation of the working range of each component to prevent overvoltage, overcurrent and overtemperature. As shown in Fig. 13, it is a block diagram of the whole vehicle diagnosis and correction method. The calculation result of the vehicle diagnosis correction method is the motor target torque diagnosis correction value

and DC/DC target current diagnostic correction values

The meanings of the variables in the figure are:

λ _cL Motor target torque correction coefficient determined according to leakage degree

λ _fc Motor target torque correction factor determined according to fuel cell diagnostic information

λ _hL Motor target torque correction factor determined according to the degree of hydrogen leakage

λ _mcu Motor target torque correction coefficient determined according to MCU temperature

λ _{m, temp} is the motor target torque correction factor determined according to the motor temperature

λ _Tbat Motor target torque correction coefficient determined according to power battery temperature

λ _Ubat Motor target torque correction coefficient determined according to the bus voltage

μ _cL is the DC/DC target power correction factor determined according to the degree of leakage

μ _dc1 is the DC/DC target power correction factor determined according to the DC/DC output current I _dc

μ _dc2 DC/DC target power correction factor determined according to DC/DC operating temperature T _dc

μ _dc3 DC/DC target power correction factor determined according to DC/DC input voltage U _fc

μ _fc DC/DC target power correction factor determined according to fuel cell diagnostic information

μ _hL DC/DC target power correction factor determined according to the degree of hydrogen leakage

μ _Tfc is the DC/DC target power correction factor determined according to the fuel cell cooling water temperature

根据燃料电池冷却水温度确定的DC/DC目标电流修正值(A)

DC/DC target current correction value (A) determined according to fuel cell cooling water temperature

根据MCU温度确定的电机目标转矩修正值(N.m)

Motor target torque correction value (Nm) determined according to MCU temperature

根据电机温度确定的电机目标转矩修正值(N.m)

Motor target torque correction value determined according to motor temperature (Nm)

根据动力电池温度确定的电机目标转矩修正值(N.m)

Motor target torque correction value determined according to power battery temperature (Nm)

7. Optimized distribution of equivalent hydrogen consumption

As shown in Figure 14, in the equivalent hydrogen consumption optimization distribution module, the target power of the whole vehicle is optimally distributed between the power battery and the fuel cell, so as to minimize the equivalent hydrogen consumption of the system and keep the balance of the SOC value, which can maximize the Optimize the efficiency of the fuel cell system and ensure that the power battery has sufficient power to ensure the power of the vehicle. In the optimal allocation of equivalent hydrogen consumption, it is first necessary to calculate the optimal power P _bat,opt of the power battery:

${\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; bat</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; opt</span>}}<span\; class="notranslate">\; =</span>\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; the\; bus</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; min</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; ocv</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; the\; bus</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; min</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; dis</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="K"\; filenames="HDA0000053476110000071.png"\; state="\{\{state\}\}">K</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; \&le;</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; min</span>}}\\ {\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; ocv</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="K"\; filenames="HDA0000053476110000071.png"\; state="\{\{state\}\}">K</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; 4</span>}\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; dis</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; min</span>}}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="K"\; filenames="HDA0000053476110000071.png"\; state="\{\{state\}\}">K</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; 1</span>}\\ \mathrm{<span\; class="notranslate">\; 0,1</span>}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="K"\; filenames="HDA0000053476110000071.png"\; state="\{\{state\}\}">K</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; /</span><span\; class="notranslate">\; (</span>\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{{\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; chg</span>}}}\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{{\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; dis</span>}}}<span\; class="notranslate">\; )</span>\\ {\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; ocv</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="K"\; filenames="HDA0000053476110000071.png"\; state="\{\{state\}\}">K</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{{\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; chg</span>}}}\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{{\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; dis</span>}}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; 4</span>}\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; chg</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; /</span><span\; class="notranslate">\; (</span>\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{{\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; chg</span>}}}\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{{\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; dis</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="K"\; filenames="HDA0000053476110000071.png"\; state="\{\{state\}\}">K</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; cax</span>}}<span\; class="notranslate">\; /</span><span\; class="notranslate">\; (</span>\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{{\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; chg</span>}}}\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{{\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; dis</span>}}}<span\; class="notranslate">\; )</span>\\ <span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; the\; bus</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; the\; bus</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; ocv</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; chg</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="K"\; filenames="HDA0000053476110000071.png"\; state="\{\{state\}\}">K</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; \&Greater\; Equal;</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; /</span><span\; class="notranslate">\; (</span>\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{{\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; chg</span>}}}\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{{\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; dis</span>}}}<span\; class="notranslate">\; )</span>\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 7</span>}<span\; class="notranslate">\; )</span>$

In formula (7), U _bus,min is the minimum value of the bus voltage, U _bus,max is the maximum value of the bus voltage, U _ocv is the power battery terminal voltage, R _dis is the discharge internal resistance, R _chg is the charging internal resistance, and is the average discharge efficiency and average charge efficiency of the power battery, K' ₁ and x are custom parameters:

$\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="K"\; filenames="HDA0000053476110000071.png"\; state="\{\{state\}\}">K</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; \&kappa;</span>}\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{{\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; chg</span>}}}\\ {\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; min</span>}}<span\; class="notranslate">\; =</span>\sqrt{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; 4</span>}\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; the\; bus</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; min</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; the\; bus</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; min</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; ocv</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; ocv</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}\\ {\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; =</span>\sqrt{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; 4</span>}\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; the\; bus</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; the\; bus</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; ocv</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; ocv</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}\end{array}\right.<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 8</span>}<span\; class="notranslate">\; )</span>$

In formula (8), κ is the correction coefficient, which is defined as:

κ＝1-2μ(SOC-0.5(SOC _H +SOC _L ))(SOC _H -SOC _L ), (9)

In formula (9), μ is the power battery SOC balance correction coefficient. SOC _H is the upper limit value of SOC, and _SOCL is the lower limit value of SOC. According to different road conditions, adjust the value of the power battery SOC balance correction coefficient μ to ensure that the SOC is within the range of [ _SOCL , _SOCH ]. As shown in Figure 15, it is the calculation result of the relationship between the optimal power of the power battery and the SOC when the power battery SOC balance correction coefficient μ=0.6.

According to the optimal power of the power battery, the optimal target power of DC/DC can be calculated for:

${\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; opt</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; max</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; /</span>{\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; aux</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; bat</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; opt</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; min</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; )</span>$

为驱动电机目标功率，是电机制动目标转矩与电机实际转速的乘积，P_bat，opt为动力电池最优功率。DC/DC动态目标电流

为：In formula (10), P _dc,max is the maximum output power of DC/DC, P _dc,min is the minimum output power, P _aux is the auxiliary power of the vehicle (calculated in the road condition adaptive compensation module), η _m is the motor efficiency,

is the target power of the driving motor, and is the target torque of the motor braking The product of the actual speed of the motor, P _{bat, opt} is the optimal power of the power battery. DC/DC dynamic target current

for:

${\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="I\; dc"\; filenames="HDA0000053476110000071.png"\; state="\{\{state\}\}">I</figure-callout></span><figure-callout\; id="1"\; label="I\; dc"\; filenames="HDA0000053476110000071.png"\; state="\{\{state\}\}">\; </figure-callout>}}_{\mathrm{<span\; class="notranslate">\; </span>}}^{\mathrm{<span\; class="notranslate">dc</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; opt</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; /</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; the\; bus</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 11</span>}<span\; class="notranslate">\; )</span>$

为：In formula (11), U _bus is the bus voltage. Perform first-order filtering on the DC/DC dynamic target current to obtain the DC/DC target current

for:

${\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="dc"\; filenames="HDA0000053476110000071.png"\; state="\{\{state\}\}">dc</figure-callout></span>}\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; *</span>}}{{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}}\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 12</span>}<span\; class="notranslate">\; )</span>$

为DC/DC动态目标电流。In formula (12), τ _dc is the DC/DC dynamic compensation time constant (calculated in the road condition adaptive compensation module),

is the DC/DC dynamic target current.

8. The vehicle controller sends the corrected motor target torque and DC/DC target current to the motor controller and DC/DC controller through the TTCAN bus to realize the output power control of the motor and fuel cell.

The calculation method of the corrected motor target torque and DC/DC target current is:

$\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; mod</span>}\mathrm{<span\; class="notranslate">\; identified</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&Delta;I</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; mod</span>}\mathrm{<span\; class="notranslate">\; identified</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&Delta;I</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; mod</span>}\mathrm{<span\; class="notranslate">\; identified</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}^{<span\; class="notranslate">\; *</span>}\\ {\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; mod</span>}\mathrm{<span\; class="notranslate">\; identified</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&Delta;T</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; mod</span>}\mathrm{<span\; class="notranslate">\; identified</span>}}^{<span\; class="notranslate">\; *</span>}\end{array}\right.<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 13</span>}<span\; class="notranslate">\; )</span>$

为电机目标转矩，其在制动状态时为

其余状态为

为电机目标转矩诊断修正值。为未经修正的DC/DC目标电流，

为考虑动力电池SOC值平衡的DC/DC目标电流修正值，为DC/DC目标电流诊断修正值，为驱动电机目标转矩诊断修正值。In formula (13)

is the target torque of the motor, which is in the braking state

The remaining status is

It is the correction value for motor target torque diagnosis. is the uncorrected DC/DC target current,

In order to consider the DC/DC target current correction value of the power battery SOC value balance, is the DC/DC target current diagnostic correction value, Diagnostic correction value for the target torque of the driving motor.

Claims (6)

1. A fuel cell hybrid vehicle control method, comprising the following steps: 1) Set up a motor state switching module, a driver command interpretation module, a power battery charge state verification module, a road condition adaptive compensation module, a vehicle diagnostic correction module and an equivalent hydrogen consumption optimization distribution module in the vehicle controller; 2) The vehicle controller reads the driver's gear signal, driver's pedal signal and TTCAN bus communication data from the digital quantity, analog quantity and TTCAN communication port, wherein TTCAN is a time-triggered controller local area network; 3) The motor state switching module switches the motor state between "driving, idling, coasting, braking, and reversing" according to the driver's gear signal and the driver's pedal signal; 4) The driver command interpretation module determines the motor state according to the motor state signal set by the motor state switching module, and then determines the motor target torque; 5) The power battery state of charge verification module verifies the SOC value sent by the power battery management system, as well as the TTCAN bus voltage and the power battery current, wherein the SOC value is the power battery state of charge verification value; Among them, the verification process of the power battery state of charge verification module is as follows: ① Use the least squares recursive algorithm to estimate the current power battery open circuit voltage and average charge and discharge internal resistance online, and combine the power battery open circuit voltage-SOC curve and charge and discharge internal resistance-SOC curve to reverse the SOC value; ② According to the SOC value sent by the power battery management system, combined with the power battery open circuit voltage-SOC curve and charge and discharge internal resistance-SOC curve, calculate the power battery open circuit voltage and average charge and discharge internal resistance; ③According to the open circuit voltage, average charge and discharge internal resistance, and SOC value sent by the power battery management system calculated in step ②, calculate the relative value of the open circuit voltage, average charge and discharge internal resistance, and SOC value estimated in step ①. error; ④ If the relative errors of the three parameters are all less than 10%, the power battery state of charge verification module determines that the SOC value sent by the power battery management system is credible; otherwise, the power battery state of charge verification module adopts the method obtained in step ① The estimated SOC value of the power battery management system replaces the SOC value sent by the power battery management system; 6) The road condition adaptive compensation module calculates the auxiliary power P _aux of the vehicle and the DC/DC dynamic compensation time constant τ _dc online according to the received component status information, and compensates the SOC value of the power battery and the performance degradation of the fuel cell. Adaptation; 7) The vehicle diagnosis and correction module corrects the motor target torque and DC/DC target current according to the limitation of the working range of each component; 8) In the equivalent hydrogen consumption optimization distribution module, the target power of the whole vehicle is optimally distributed between the power battery and the fuel cell, so as to minimize the equivalent hydrogen consumption of the system and keep the SOC value balanced; 9) The vehicle controller sends the corrected motor target torque and DC/DC target current to the motor controller and DC/DC controller through the TTCAN bus to realize the output power control of the motor and fuel cell. 2. A fuel cell hybrid vehicle control method according to claim 1, characterized in that: in the step 3), the switching steps of the motor state switching module are as follows: ① Determine whether the driver’s gear signal is neutral, if so, set the motor state to idle speed, otherwise go to the next step; ② Determine whether the gear signal is a reverse gear, if so, set the motor state to reverse; otherwise, go to the next step; ③Judge whether the brake pedal is greater than the braking threshold, if so, set the motor state to brake; otherwise, go to the next step; ④ Determine whether the brake pedal is less than or equal to the braking threshold, and the accelerator pedal is greater than the acceleration threshold. If so, set the motor state to driving, otherwise, set the motor state to coasting. 3. The fuel cell hybrid vehicle control method according to claim 1, characterized in that: in step 4), the driver command interpretation module determines when the motor is in the state of idling, reversing, driving and coasting , then the motor target torque is the driving target torque

${\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; qd</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; \&alpha;T</span>}}_{\mathrm{<span\; class="notranslate">\; qd</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$ In the above formula, α is the position signal of the driver’s pedal, and the value range is 0 to 1; T _qd,max is the maximum driving torque of the motor. According to the external characteristic curve and the target torque relationship diagram of the motor in the driving state, the driving target torque can be obtained

value; When the driver command interpretation module determines that the motor is in a braking state, the motor target torque is the braking target torque

$T_{\mathrm{qb}}^{*}=T_{\mathrm{qb},\max }\mathrm{\&gamma;},$ In the above formula, γ is the coefficient of the brake pedal, and T _qb,max is the maximum braking torque. According to the external characteristic curve and the target torque relationship diagram of the motor in the braking state, the braking target torque can be obtained

value. 4. A fuel cell hybrid vehicle control method according to claim 3, characterized in that: the brake pedal coefficient γ, when adopting the series braking energy feedback strategy, the brake pedal coefficient γ Obtained by the following formula: γ=4(β-β ₁ )(β-β ₂ )(β ₁ -β ₂ ) ^-2 , In the above formula, β is the brake pedal position signal, β ₁ and β ₂ are the parameters of the braking feedback strategy, which affect the braking effect of the vehicle, and are calibrated according to the actual situation. 5. A fuel cell hybrid vehicle control method according to claim 1, characterized in that: in said step 6), in said road condition adaptive compensation module, said vehicle auxiliary power P _aux is based on TTCAN bus data, using the first-order low-pass filter algorithm for online estimation: ${\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; aux</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; bat</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; in</span>}}}{{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; aux</span>}}\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; ,</span>$ In the above formula, P _dc is the DC/DC output power, P _bat is the power battery output power, P _m,in is the motor input power, all of which can be read from the TTCAN bus data, τ _aux is the filter constant, and s is the complex number of the transfer function variable; The DC/DC dynamic compensation time constant τ _dc is calculated as follows: τ _dc =λ ₁ Δτ _dc1 +λ ₂ Δτ _dc2 +λ ₃ Δτ _dc3 +τ _dc0 , In the above formula, λ ₁ , λ ₂ , and λ ₃ are the fuel cell performance degradation weighting coefficients: λ ₁ =0.4, λ ₂ =0.4, λ ₃ =0.2, τ _dc0 =5s, Δτ _dc1 is the open circuit according to the fuel cell system UI curve parameters The correction value determined by the voltage U ₀ , Δτ _dc2 is the correction value determined according to the fuel cell system UI curve parameter ohmic internal resistance R _fc , Δτ _dc3 is the correction value determined according to the fuel cell system UI curve parameter concentration polarization parameter b, Δτ _dc1 , Δτ _dc2 and Δτ _dc3 vary with the performance degradation of the fuel cell stack. 6. A fuel cell hybrid vehicle control method according to claim 1, characterized in that: in said step 9), the corrected calculation formulas of the motor target torque and DC/DC target current are as follows : $\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; mod</span>}\mathrm{<span\; class="notranslate">\; identified</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&Delta;I</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; mod</span>}\mathrm{<span\; class="notranslate">\; identified</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&Delta;I</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; mod</span>}\mathrm{<span\; class="notranslate">\; identified</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}^{<span\; class="notranslate">\; *</span>}\\ {\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; mod</span>}\mathrm{<span\; class="notranslate">\; identified</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&Delta;T</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; mod</span>}\mathrm{<span\; class="notranslate">\; identified</span>}}^{<span\; class="notranslate">\; *</span>}\end{array}\right.<span\; class="notranslate">\; ,</span>$ In the above formula

is the motor target torque,

is the motor target torque diagnosis correction value,

is the uncorrected DC/DC target current,

In order to consider the DC/DC target current correction value of the power battery SOC value balance,

is the DC/DC target current diagnostic correction value, Diagnostic correction value for the target torque of the driving motor.

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