燃料电池EIS检测中DC/DC变换器的预测控制研究

摘要

电化学阻抗谱(EIS)是燃料电池性能的重要指标,对其精确检测是燃料电池系统高效、可靠运行的重要保障.此处EIS检测是将DC/DC纹波进行调制,作为激励源引入燃料电池,该方法对DC/DC控制器的快速性和稳定性提出了很高要求.提出了一种超调量小、调节时间短的模型预测控制算法作为控制策略,首先建立Boost电路模型,通过近似化和线性化,获取线性状态空间方程;在参考电压中引入三角波扰动,通过显式模型预测控制算法计算,得到最优的占空比反馈给Boost电路的开关管,从而满足控制的快速性和稳定性.最后通过仿真和实验结果,验证了模型预测控制的有效性和可行性.%Electrochemical impedance spectroscopy(EIS) is one of the important indicators for the fuel cell performance,so its accurate measurement is necessary for the fuel cell system's efficient and reliable operation.The fuel cell EIS measurement is to modulate DC/DC ripple which is introduced into the fuel cell as excitation source.In order to meet requirements of rapidity and stability in DC/DC controller,model predictive control algorithm is proposed.First of all,the linear state space equation is obtained by linearizing Boost circuit model.The triangular wave disturbance is added in the reference voltage which is used to compute the optimal duty cycle by using explicit model predictive control algorithm.The duty cycle is used to control the IGBT of the circuit system,thereby achieve the rapidity and stability of the control.Finally,the simulation and experimental results demonstrate the feasibility and effectiveness of the model predictive control.