基于准滑模观测器的转子位置精确估计

传统的滑模观测器采用开关函数,开关函数在切换过程中的高频抖动使得转子位置的估计出现一定的误差.通过对永磁同步电机的数学模型分析,提出用饱和函数代替开关函数,使得观测器处于准滑动模态,有效抑制高频抖动.同时,用扩展卡尔曼滤波器代替传统的低通滤波器,一方面进一步提高估计精度,另一方面省去低通滤波后的相位补偿.通过自适应的方式选取边界层的厚度,使得控制增益和抖动维持在最优状态.最后采用SIMULINK进行仿真,对方案的有效性进行验证.

Precise estimation of rotor position based on quasi-sliding mode observer

Switching function is adopted in conventional sliding mode observer(SMO) and a high-frequency jitter takes place in the switching process,so that a definite error occurs to the estimation of rotor position.By analyzing the mathematical model of permanent magnet synchronous Generator(PMSG),a saturation function was proposed to substitute for the switching function.When the saturation function was used,the observer would be in quasi-sliding mode and this could restrain the high-frequency jitter effectively.Meantime,the traditional low-pass filter could be replaced by Extended Kalman filter;this on one hand could further increase the estimation accuracy,and on the other hand,could also save the phase compensation after low-pass filtering.In the design of SMO,the boundary layer thickness was selected by using adaptive method,making the control gain and high-frequency jitter keep in an optimal state.Finally,SIMULINK simulation was carried out and the effectiveness of this method was verified with.