计及总损耗功率的电动汽车母线电容主动快速放电方法  

Active Fast Discharge Method of Bus Capacitor for Electric Vehicle with Total Power Loss

作　　者：张晓军[1] 杨家强[1] 周宇晨 Zhang Xiaojun;Yang Jiaqiang;Zhou Yuchen(School of Electrical Engineering Zhejiang University,Hangzhou 310027 China;School of Engineers Zhejiang University,Hangzhou 310015 China)

机构地区：[1]浙江大学电气工程学院,杭州310027 [2]浙江大学工程师学院,杭州310015

出　　处：《电工技术学报》2024年第6期1737-1748,共12页Transactions of China Electrotechnical Society

基　　金：浙江省自然科学基金重点基金资助项目(LCZ19E070001)。

摘　　要：针对电动汽车遇到碰撞等紧急情况时,高压驱动系统母线电容电压需迅速降到安全电压(60 V),而传统基于PI控制的母线电容主动放电方法存在鲁棒性差、放电时间长和安全性低的问题,提出一种计及总损耗功率的电动汽车母线电容快速放电方法。首先,建立以永磁同步电机绕组作为泄放电阻的母线电容能量流动模型,将逆变器损耗、电机绕组铜耗、电机电感储能等损耗作为总损耗,利用扩展滑模观测器(ESMO)对总损耗功率进行估算,并通过Lyapunov稳定性理论对ESMO的稳定性进行了证明。然后,将观测的总损耗功进行前馈补偿,从而使母线电压快速降低并稳定在安全电压。仿真和实验结果表明,与现有主动放电方法相比,所提放电方法不仅显著减小了放电时间,而且提高了快速放电的鲁棒性和安全性。When electric vehicles(EVs)encounter an emergency,the dc-bus voltage of EVs equipped with the high-voltage drive system needs to be reduced to safe voltage(60 V)as soon as possible.To drop the dc-bus capacitor voltage to a safe voltage,a winding-based active discharge method was proposed.However,traditional active discharge based on PI controller has poor robustness,long discharge time,and low safety,which cannot meet the discharge requirements of the United Nation Vehicle Regulation ECCE R94.This paper proposes an active discharge method for EVs with total power loss to reduce the discharge time and enhance the robustness.Firstly,the d-axis weakened current is calculated using the permanent magnet synchronous motor winding as the bleeding resistor.Then,the traditional active discharge method based on the PI controller is analyzed.Secondly,the dc-bus capacitor energy flow model is established.More importantly,the extended sliding mode observer(ESMO)is introduced to address long discharge time and poor robustness issues.The ESMO can observe the total loss,which consists of inverter loss,motor winding copper consumption,motor inductance energy storage,and other losses.The stability of ESMO is proved by the Lyapunov stability theory.Finally,observed total discharge loss can be feedforward compensated by the designed control law.Compared with the conventional discharge method,the influence of total power loss and motor speed on the dc-bus capacitor voltage is well suppressed,and the dc-bus capacitor voltage and motor speed are decoupled in the proposed strategy.Experimental results show that the DC-bus voltage of the proposed method drops to a safe voltage within 0.2 s,faster than traditional active discharge method-based PI controller(1.2 s)and disturbance observer(0.3 s).In contrast,the discharge time is shorter with the active discharge method-based disturbance observer because the convergence rate is faster than the disturbance observer.The experiment with parameter mismatch proves that the parameter error can be

关 键 词：电动汽车 永磁同步电机 总损耗功率估计 扩展滑模观测器 母线电容放电 

分 类 号：TM351[电气工程—电机]