阅读说明：本技术 燃料电池温度控制方法 (Fuel cell temperature control method ) 是由 石建珍 刘豹 于 2021-05-20 设计创作，主要内容包括：本发明提供了一种燃料电池温度控制方法,先获取得到当前环境温度下当前燃料电池输出功率下的风扇占空比、PID控制补偿的风扇占空比和模型预测的应该输出的风扇占空比,之后将三者相加得到风扇最终占空比,散热系统的风扇控制器按该风扇最终占空比控制风扇工作以控制燃料电池温度。本发明方法简单可行,可更快更精准地降低燃料电池的温度。(The invention provides a fuel cell temperature control method, which comprises the steps of firstly obtaining the duty ratio of a fan under the current output power of a fuel cell under the current environment temperature, the duty ratio of the fan compensated by PID control and the duty ratio of the fan which is predicted by a model and should be output, then adding the duty ratio of the fan, the duty ratio of the fan compensated by PID control and the duty ratio of the fan predicted by the model to obtain the final duty ratio of the fan, and controlling the fan to work by a fan controller of a heat dissipation system according to the final duty ratio of the fan to control the temperature of the fuel cell. The method is simple and feasible, and can reduce the temperature of the fuel cell more quickly and accurately.)

1. A fuel cell temperature control method characterized by: the method comprises the following steps:

the VCU obtains the current environment temperature in real time and calculates the real-time temperature compensation coefficient T according to the formula (1)_KThe VCU checks a table of correspondence between the output power of the fuel cell and the duty ratio of the fan according to the current output power of the fuel cell to obtain the duty ratio of the fan corresponding to the current output power of the fuel cell, and multiplies the duty ratio of the fan corresponding to the current output power of the fuel cell by the real-time temperature compensation coefficient to obtain the duty ratio of the fan under the current output power of the fuel cell at the current ambient temperature;

wherein, T_nowIs the current ambient temperature, T_calIs the ambient temperature at calibration;

II, the VCU obtains the duty ratio of a fan controlled and compensated by PID after PID processing according to the difference value between the actual temperature of the fuel cell and the target temperature of the fuel cell acquired in real time;

III, establishing a thermal management water temperature change prediction equation (2), carrying out discretization processing on the thermal management water temperature change prediction equation (2) for a certain time t to obtain a corresponding relation between the heat dissipation strength of the heat dissipation system and the temperature change rate of cooling liquid in the heat dissipation system, obtaining the total duty ratio of fans within the certain time t, obtaining the average duty ratio of fans predicted by a model according to the total duty ratio of the fans within the certain time t, determining the corresponding relation between the temperature change rate of the cooling liquid in the heat dissipation system and the average duty ratio of the fans predicted by the model, and predicting the duty ratio of the fans predicted by the model according to the relation between the temperature change rate of the cooling liquid in the heat dissipation system and the average duty ratio of the fans predicted by the model and the difference between the current temperature of the cooling liquid in the cooling system and the target temperature of the cooling liquid in the cooling system;

wherein m is the mass of the cooling liquid in the heat dissipation system, C_pdT/dT is the temperature change rate of the cooling liquid in the heat dissipation system within a certain time t, I is the real-time current of the fuel cell, U₀Open-circuit voltage of the fuel cell, U real-time voltage of the fuel cell, A effective heat dissipation area of the heat dissipation system, h heat dissipation strength of the heat dissipation system, T real-time temperature of cooling liquid in the heat dissipation system, and T₀Is the current ambient temperature;

and IV, adding the fan duty ratio under the current fuel cell output power at the current environment temperature obtained in the step I, the fan duty ratio compensated by PID control obtained in the step II and the fan duty ratio predicted to be output by the model obtained in the step III to obtain the final fan duty ratio, and controlling the fan to work by a fan controller of the heat dissipation system according to the final fan duty ratio to control the temperature of the fuel cell.

2. The fuel cell temperature control method according to claim 1, characterized in that: in the step I, a corresponding table of the output power of the fuel cell and the duty ratio of the fan is stored in the VCU in advance.

3. The fuel cell temperature control method according to claim 1 or 2, characterized in that: and step I, step II and step III are carried out synchronously.

4. The fuel cell temperature control method according to claim 1 or 2, characterized in that: in the step III, the time t is 5 s.

5. A fuel cell temperature control method according to claim 3, characterized in that: in the step III, the time t is 5 s.

Technical Field

The present invention relates to a fuel cell temperature control method.

Background

A fuel cell is a complex energy conversion device, and is considered to be an ultimate energy source in the 21 st century because of its advantages of high power generation efficiency, low environmental pollution, high specific energy, low noise, and the like.

While fuel cells require the proper temperature in service in order for the system to achieve its best performance. When the temperature of the galvanic pile is too low, the catalyst falls off from the membrane due to thermal expansion and cold contraction, and the performance of the fuel cell is influenced; when the temperature of the electric pile is too high, Pt in the catalyst is sintered, catalyst particles become large, the surface area is reduced, and the performance of the fuel cell is reduced. A reasonable temperature is of utmost importance. However, the pipeline of a heat dissipation system of the fuel-electric system is long, the phenomena of water temperature regulation overshoot and time delay are very obvious, the traditional PID regulation algorithm is difficult to regulate the parameters of the water temperature regulator, overshoot oscillation easily exists when the regulation is violent, the problem of overlong regulation time is caused when the regulation is moderate, and the temperature control of the fuel cell is not facilitated.

Disclosure of Invention

The invention aims to provide a simple and feasible fuel cell temperature control method, which can reduce the temperature of a fuel cell more quickly and accurately.

The invention is realized by the following scheme:

a fuel cell temperature control method comprises the following steps:

the VCU (vehicle control unit) acquires the current ambient temperature in real time and calculates the real-time temperature compensation coefficient according to the formula (1)T _K The VCU checks a table of correspondence between the output power of the fuel cell and the duty ratio of the fan according to the current output power of the fuel cell to obtain the duty ratio of the fan corresponding to the current output power of the fuel cell, and multiplies the duty ratio of the fan corresponding to the current output power of the fuel cell by the real-time temperature compensation coefficient to obtain the duty ratio of the fan under the current output power of the fuel cell at the current ambient temperature;

……………………………………………………（1），

wherein the content of the first and second substances,T _now is the current ambient temperature and is,T _cal is the ambient temperature at calibration;

the IIVCU obtains the duty ratio of the fan controlled and compensated by the PID after the PID processing according to the difference value between the actual temperature of the fuel cell and the target temperature of the fuel cell which is acquired in real time, the PID processing step is carried out according to the prior art, and the adjustment of the parameters related to the PID processing can be simplified in the actual processing process, so that the influence weight of the duty ratio of the fan controlled and compensated by the PID obtained after the PID processing to the final duty ratio of the fan is smaller;

III, establishing a thermal management water temperature change prediction equation (2), carrying out discretization processing on the thermal management water temperature change prediction equation (2) for a certain time t to obtain a corresponding relation between the heat dissipation strength of the heat dissipation system and the temperature change rate of cooling liquid in the heat dissipation system, obtaining the total duty ratio of fans within the certain time t, obtaining the average duty ratio of fans predicted by a model according to the total duty ratio of the fans within the certain time t, determining the corresponding relation between the temperature change rate of the cooling liquid in the heat dissipation system and the average duty ratio of the fans predicted by the model, and predicting the duty ratio of the fans predicted by the model according to the relation between the temperature change rate of the cooling liquid in the heat dissipation system and the average duty ratio of the fans predicted by the model and the difference between the current temperature of the cooling liquid in the cooling system and the target temperature of the cooling liquid in the cooling system;

……………………………………（2），

wherein m is the mass of the cooling liquid in the heat dissipation system, C_pdT/dT is the temperature change rate of the cooling liquid in the heat dissipation system within a certain time t, I is the real-time current of the fuel cell, U₀Open-circuit voltage of the fuel cell, U real-time voltage of the fuel cell, A effective heat dissipation area of the heat dissipation system, h heat dissipation strength of the heat dissipation system, T real-time temperature of cooling liquid in the heat dissipation system, and T₀Is the current ambient temperature;

and IV, adding the fan duty ratio under the current fuel cell output power at the current environment temperature obtained in the step I, the fan duty ratio compensated by PID control obtained in the step II and the fan duty ratio predicted to be output by the model obtained in the step III to obtain the final fan duty ratio, and controlling the fan to work by a fan controller of the heat dissipation system according to the final fan duty ratio to control the temperature of the fuel cell.

Further, in the step I, a corresponding table of the output power of the fuel cell and the duty ratio of the fan is stored in the VCU in advance, the corresponding table is obtained according to the calibration of the real vehicle test, and the environmental temperature when the corresponding table is calibrated isT _cal 。

Further, the step I, the step II and the step III are synchronously carried out.

Further, in the step III, the time t is 5 s.

The fuel cell temperature control method is simple and feasible, the corresponding relation between the heat dissipation intensity h of the heat dissipation system and the temperature change rate of the cooling liquid in the heat dissipation system and the corresponding relation between the temperature change rate of the cooling liquid in the heat dissipation system and the average fan duty ratio predicted by the model are obtained by establishing a heat management water temperature change prediction equation, and the fan duty ratio required by adjusting to the target temperature of the cooling liquid of the heat dissipation system, namely the fan duty ratio predicted by the model and to be output is predicted, so that the responsiveness of the heat dissipation system can be rapidly improved; meanwhile, in the method, the regulation of the PID parameter is simplified, so that the influence weight of the duty ratio of the PID control compensation fan obtained after PID processing on the final duty ratio of the fan is smaller, the system overshoot is smaller or not, the parameter regulation is simple and effective, and the temperature control of the fuel cell is quicker and more accurate. The method has low dependence on PID and accurate control of model prediction, so that the method has strong applicability, and PID parameters can meet the requirements without readjustment after being transplanted to other vehicle types.

Detailed Description

The present invention will be further described with reference to the following examples, but the present invention is not limited to the description of the examples.

Example 1

A temperature control method of a fuel cell is carried out according to the following steps, wherein the steps I, II and III are carried out synchronously:

the VCU (vehicle control unit) acquires the current ambient temperature in real time and calculates the real-time temperature compensation coefficient according to the formula (1)T _K The VCU checks a table of correspondence between the output power of the fuel cell and the duty ratio of the fan according to the current output power of the fuel cell to obtain the duty ratio of the fan corresponding to the current output power of the fuel cell, and multiplies the duty ratio of the fan corresponding to the current output power of the fuel cell by the real-time temperature compensation coefficient to obtain the duty ratio of the fan under the current output power of the fuel cell at the current ambient temperature; the corresponding table of the output power of the fuel cell and the duty ratio of the fan is stored in a VCU in advance, the corresponding table is obtained according to the real vehicle test calibration, and the environmental temperature when the corresponding table is calibrated isT _cal ；

……………………………………………………（1），

Wherein the content of the first and second substances,T _now is the current ambient temperature and is,T _cal is the ambient temperature at calibration;

the IIVCU obtains the duty ratio of the fan controlled and compensated by the PID after the PID processing according to the difference value between the actual temperature of the fuel cell and the target temperature of the fuel cell which is acquired in real time, the PID processing step is carried out according to the prior art, and the adjustment of the parameters related to the PID processing can be simplified in the actual processing process, so that the influence weight of the duty ratio of the fan controlled and compensated by the PID obtained after the PID processing to the final duty ratio of the fan is smaller;

III, establishing a heat management water temperature change prediction equation (2), carrying out discretization treatment on the heat management water temperature change prediction equation (2) for a certain time t to obtain a corresponding relation between the heat dissipation intensity of the heat dissipation system and the temperature change rate of cooling liquid in the heat dissipation system, and obtaining the total duty ratio of the fan within the certain time t, obtaining the average duty ratio of the fan predicted by the model according to the total duty ratio of the fan within a certain time t, determining the corresponding relation between the temperature change rate of the cooling liquid in the heat dissipation system and the average duty ratio of the fan predicted by the model, predicting to obtain the duty ratio of the fan to be output, which is predicted by the model, according to the relation between the temperature change rate of the cooling liquid in the heat dissipation system and the average duty ratio of the fan predicted by the model and the difference between the current temperature of the cooling liquid in the cooling system and the target temperature of the cooling liquid in the cooling system, wherein the time t is 5 s;

……………………………………（2），

wherein m is the mass of the cooling liquid in the heat dissipation system, C_pdT/dT is the temperature change rate of the cooling liquid in the heat dissipation system within a certain time t, and I is the actual temperature of the fuel cellTime current, U₀Open-circuit voltage of the fuel cell, U real-time voltage of the fuel cell, A effective heat dissipation area of the heat dissipation system, h heat dissipation strength of the heat dissipation system, T real-time temperature of cooling liquid in the heat dissipation system, and T₀Is the current ambient temperature;

and IV, adding the fan duty ratio under the current fuel cell output power at the current environment temperature obtained in the step I, the fan duty ratio compensated by PID control obtained in the step II and the fan duty ratio predicted to be output by the model obtained in the step III to obtain the final fan duty ratio, and controlling the fan to work by a fan controller of the heat dissipation system according to the final fan duty ratio to control the temperature of the fuel cell.