永磁同步电机(Permanent Magnet Synchronous Motor,PMSM) 是一个强耦合、多变量、复杂的非线性系统，它具有运行效率比较高、体积小、结构比较简单等诸多优点，普遍的应用到高性能的控制领域中。然而，在一些复杂的控制环境中，存在许多的不确定的要素要解决，比如外部的扰动、内部参数的摄动等等，都是为了满足性能稳定和可靠性高的控制需求。本文以永磁同步电机调速系统为研究对象，研究了滑模变结构控制理论、根轨迹的稳定性和扩张状态观测器理论，探讨它们的实现方法和策略。 首先，研究了永磁同步电机控制策略的发展现状，搭建了永磁同步电机的数学模型，采用了矢量控制调速这一方案。同时分析了永磁同步电机的矢量控制原理和空间电压脉宽调制技术，论述了矢量控制系统的可行性，并最终确立了的控制方法。 其次，根据经典控制理论中的时域法、根轨迹法为基础，设计速度环和电流环的双闭环控制器，并且详细的分析了该控制器调节参数的设计方法和原理。 再次，根据PMSM的数学模型，由于常规的PI控制很容易受到参数的变化以及外界干扰的影响，其无法满足在高精度的调速场合的控制需求。针对传统的滑模控制存在稳态误差和系统抖振问题，改进了一种复合积分滑模面，有效的削弱抖振并且减少了稳态误差；针对其抖振水平和趋近速度存在矛盾性问题，因此引入了一种新型的趋近律，可以减小抖振的同时提高了其趋近滑模面的速度；针对电机周围存在未知干扰以及电机内部参数的变化导致电机运行性能的下降，引入了扩张状态观测器，并给出了相应控制器的设计方案。 最后，搭建PMSM的Simulink仿真模型，对相关的控制算法进行验证，得出了本文所介绍控制算法的可行性，同时以TMS320F28335为控制核心，搭建相关的实验平台且对部分算法实施工程验证。本文所改进的复合积分滑模算法具有普遍的适用性，对伺服调速系统有一定的现实意义。

Permanent magnet synchronous motor (PMSM) is a strongly coupling, multivariable and complex nonlinear system.PMSM is widely applied to the field of high performance control,because of its high efficiency, small volume, and simple structure. However, in some complex control areas, there are many uncertain factors which including external disturbance and parameter perturbation to be solved in order to meet control requirements of the high performance and reliability. This paper takes the permanent magnet synchronous motor speed control system as the research object, studies the sliding mode variable structure control theory, the stability of the root locus and the fractional calculus theory, and discusses their control methods and strategies. First, development status of Permanent Magnet Synchronous Motor Control Strategy is studied, then the mathematical model of PMSM is built, and control strategy of vector control is adopted. At the same time, the vector control principle and space vector pulse width modulation technology of PMSM are analyzed, the feasibility of vector control system is discussed, and finally the control method of is established. Secondly, based on analytical method of the time domain and the root locus in the classical control theory, a double closed loop controller is designed for the speed loop and the current loop, and the design method and principle of the controller's tuning parameters are analyzed in detail. Thirdly, according to the mathematical model of PMSM, the conventional PI controller is easily affected by changes in parameters and external disturbance, and it cannot meet system requirements in high-precision speed-regulation applications. For the problems of steady-state error and system chattering for traditional sliding mode control, a kind of composite integral sliding mode surface is improved, which effectively suspress buffeting and reduces steady-state error. A novel sliding-mode reaching law is proposed which not noly can reduce the chartering but aslo increase convergence speed of approaching the sliding-mode surface.Aiming at the unknown disturbance around the motor and the change of the motor internal parameters, the expansion performance of the motor is introduced. The expansion observer is introduced and the corresponding controller design scheme is given. Finally, the simulink simulation model of PMSM was built, and the relevant control algorithm was verified. The feasibility of the control algorithm introduced was obtained in this paper. At the same time, it takes the TMS320F28335 control chip as the core, and builds the related experimental platform and implements the engineering verification of the proposed partial algorithm. The integral sliding mode algorithm proposed has universal applicability and certain practical significance for servo speed control system in this paper.