感应电机二阶滑模次优算法定子磁链观测器设计

Design of second order sliding-mode sub-optimal algorithm stator flux observer for induction motor

提出了基于二阶滑模次优算法的感应电机定子磁链观测方法,设计了定子磁链观测器,并应用到感应电机直接转矩控制中.本文设计的磁链观测器,通过准确的跟踪电流及其变化率,从而实现对转子磁链的准确估算,然后利用转子磁链与定子磁链的关系,估算出定子磁链.由于本文设计的定子磁链观测器是一个多输入多输出(MIMO)系统,稳定性分析非常复杂,为此将磁链估算误差的微分看作扰动处理,从而将MIMO的观测器模型分解成两个独立的单输入单输出(SISO)系统,简化了稳定性分析.将该观测器用于感应电机直接转矩控制中,达到了很好的控制效果.仿真和实验验证了该方法的有效性.

This paper proposes a stator flux estimation method for induction motor based on the second order slidingmode sub-optimal algorithm. A stator flux observer is designed and applied to the direct torque control （DTC） of an induction motor. The flux observer tracks stator current and the differential of stator current accurately to realize accurate estimation of the rotor flux, and then estimate the stator flux using the relationship between the stator flux and the rotor flux. Because the stator flux observer is a multi-input multi-output （MIMO） system and is complicated in stability analysis, we treat the differential of estimated flux error as disturbance and divide the multi-input multi-output observer model into two separate single input single output （SISO） systems, which simplifies the stability analysis. The observer is applied to the direct torque control of an induction motor and achieves a very good control results. Simulation experiment results validate the proposed method.