无速度传感器感应电机滑模磁链与速度观测新方法

New sliding-mode flux and speed observer for speed sensorless induction motor system

基于滑模变结构技术提出一种新的滑模电流与磁链观测策略,用于感应电机的高精度转速估计.以定子电流与转子磁链为状态变量,采用非线性系统分析方法建立了误差状态方程,设计了合理的滑模流形面,根据Lyapunov稳定性条件,推导出定子电流和转子磁链观测方程,分析得到观测器的收敛条件,证明了其稳定性,进而得到转速和转子时间常数估计表达式.该策略能对转速和转子时间常数进行高精度的在线估计,并能克服电机参数变化与负载扰动而引起的性能下降问题,具有估计精度高、收敛速度快、鲁棒性强等优点.

Proposed a new sliding mode flux and current obserser by using variable structure technology in order to obtain high-precision speed estimation for induction motor （IM） drives. The tracking error dynamics was firstly obtained through nonlinear control theory. Then, the sliding surface was designed to guarentee the convergence of the speed tracking error to zero. By using Lyapunov arguments, the observered equations of the stator current and the rotor flux were deduced and the convergence condition was obtained. Therefore, the estimation algorithm for rotor speed and time constant were solved to guarentee the stability of the system. The scheme has the high-precision estimation ability and can avoid the performance decrease since it is robust to the variation of motor parameters and load disturbances. Besides, the scheme has the advantage of fase convergence rate.