中文摘要：

针对永磁同步电机（PMSM）调速系统易受到参数不确定性及负载扰动的影响，提出了一种新型可变边界层的非奇异快速终端滑模（NFTSM）控制策略。通过构建可在有限时间内快速收敛的非奇异快速终端滑模面，结合含转速与q轴定子电流的二阶模型得到速度环滑模控制律,减小了转速与q轴定子电流一阶模型所引起的误差，并避免了终端滑模面奇异问题。最后，设计可变边界层使误差减小至阈值时系统状态切换至小边界层，实现抖振和跟踪精度的协调控制。数值仿真结果表明，NFTSM 控制策略与传统 PI 控制相比,转速超调量小，响应速度快，稳态精度近似为 0，针对参数摄动和负载扰动鲁棒性强，且在有效削弱抖振的同时保证了转速的稳态精度。

英文摘要：

A nonsingular fast terminal sliding mode（NFTSM）controller with varying boundary layers is proposed to solve the problem that speed-regulation systems of permanent magnet synchronous motors（PMSM）are susceptible to parameter uncertainties and disturbances of external loads.The sliding mode control law for speed loop is developed through building the NFTSM surface with fast convergence in a finite time and using the second-order model of rotary speed and q-axis stator reference current so that the errors caused by the first-order model of rotary speed and q-axis stator reference current are decreased and the singular problem of the terminal sliding mode surface is avoided.Furthermore,the varying boundary layer is designed to make the system states switch to a small boundary layer when the error decreases to a threshold so that the coordinated control between chattering and tracking accuracy is realized.Numerical simulation results and a comparison with the traditional PI control show that the proposed NFTSM control scheme achieves smaller overshoot and faster response,and the steady-state error is near to zero.Moreover,the NFTSM has strong robustness in parameter variations and disturbances of external loads,and ensures a higher steady-state precision of the speed withalower chattering.