基于二阶滑模的电动汽车感应电动机速度辨识

Speed identification of induction motor used in electric vehicle based on second order sliding mode

针对电动汽车电动机驱动系统在恶劣的运行环境中对速度精度要求较高的问题,提出了基于二阶滑模观测器的速度辨识方法.观测器以转子磁链和定子电流为状态变量,通过输入等效控制量,使解耦系统最终稳定在设计的两个滑模超平面上,从而实现对转子速度的估计和转子电阻的在线辨识.引入超螺旋算法将传统的开关式滑模控制变为连续控制,大幅度降低了系统抖振,提高了观测精度.仿真结果表明,该观测器在全速范围具有良好的动态性能和较高的观测精度,满足驱动系统要求.

For the problem that the motor drive system used in electric vehicle requires the higher speed accuracy when operating in dangerous environment,a speed identification method based on second order sliding mode observer was presented.Both rotor flux and stator current were used as the state variables in this observer.The decoupled system was stabilized at two designed sliding mode surfaces through equivalent control variable input to realize the on-line identification of the rotor speed and rotor resistance.The supertwisting algorithm was used to change traditonal switching control into continuous control.Thus,the chattering in the system gets greatly reduced and the observation precision is improved.The simulation results show that the observer has good dynamic performance and high observation precision in whole speed range,which can meet the requirements of the drive system.