中文摘要：

在永磁直线同步电机（permanent-magnet linear synchronous motor，PMLSM）伺服系统中，模型的阶次高，且速度和电流等变量问存在的耦合严重影响速度跟踪的快速性和精度。采用基于奇异摄动理论的对角化方法将永磁直线同步电机伺服系统分解成慢变和快变子系统。为了保证系统的鲁棒性，利用2阶滑模控制的次优算法分别独立设计慢变和快变子系统的控制律，再将2个控制律合成得到永磁直线同步电机的复合控制律。仿真结果表明，所提出的策略具有良好的速度跟踪性能，同时对负载扰动和参数变化具有很强的鲁棒性。

英文摘要：

The model of permanent-magnet linear synchronous motor （PMLSM） is a high order one, and the speed-tracking rapidity and precision are influenced by the coupling between variables such as speed and currents. The diagonalization method based on singular perturbation theory was applied to decouple the PMLSM high order model into two lower order subsystems at two different time scales. Then the two subsystems controllers were designed separately by using sub-optimal algorithm, which is one of＇the second order sliding mode control algorithms, to obtain robustness against the uncertainties. The composite control laws were achieved by composing the control signals of two subsystems with each other. Simulation results show that this strategy has good performance in speed tracking, and strong robustness against load disturbances and parameters uncertainties.