一种带非电解电容的电动汽车充电电源的建模和设计方法

摘要

电动汽车车用电池的寿命通常在50000 h以上,而传统的电动汽车车用充电电源寿命受电解电容的限制只能在8000h左右.为实现充电电源与动力电池的寿命匹配,关键在于将短寿命的DC-link电解电容替换为长寿命的非电解电容或代替电容的其他结构.本文提出了一种基于状态空间平均法的建模方法,重构了包括控制电路和主电路的平均控制模式下的Boost PFC电路.并通过该方法得到全电路的控制框图,最终得到了输出电压对输入电压的闭环传递函数,进而得到了100 Hz两倍工频纹波电压的衰减倍数与DC-link电容之间的关系,证明了DC-link电容容值可以大大低于传统的经验值,实现了长寿命小容值的薄膜电容对短寿命大容值电解电容的替换.最后用仿真和实验样机对该建模方法以及电源的无电解电容化进行了验证.%The battery lifetime used in EV is usually above 50 000 h,while the lifetime of charging power used in traditional EV limited by electrolytic capacitor is only up to 8 000 h.In order to lengthen the lifetime of electrical vehicle charging power,there is an urgent need to replace the DC-link electrolytic capacitors in electrical vehicle charging power supply by non-electrolytic capacitors.This paper proposes a new method to model ACM Boost PFC circuit including main circuit and control system,and the control block diagram of overall circuit is obtained.The close-loop transfer function of output voltage variation with respect to input voltage perturbation is obtained,and then,the attenuation coefficient for 100 Hz twice line frequency ripple voltage is calculated.It is proved that the capacitance value of DC-link can be significantly lower than that of traditional experience value.The electrolytic capacitor with short-lived and large-capacitance is replaced by thin-film capacitor with long-life and small-capacitance.Finally,the modeling method and the non-electrolytic capacitance of the power supply are verified by simulation and experimental prototype.