基于改进型双幂次趋近律与全局快速终端滑模观测器的IPMSM调速系统滑模控制

Sliding Mode Control of IPMSM Speed Regulation System Based on An Improved Double Power Reaching Law and Global Fast Terminal Sliding Mode Observer

针对内置式永磁同步电机(IPMSM)速度环中存在的内部参数摄动与外部负载扰动等问题,为了提高速度控制系统的动态性和鲁棒性,该文提出一种基于改进型双幂次趋近律(IDPRL)与全局快速终端滑模观测器(GFTSMO)的滑模控制方法。所提趋近律在幂次项中引入系统状态变量,减少了稳态误差,解决了快速趋近滑模面和抖振抑制之间的矛盾。设计一种基于IDPRL的IPMSM滑模速度控制器。为了进一步减少系统状态的稳态误差,设计了一种GFTSMO,该观测器不仅能够减少趋近律的开关增益,还能实现系统扰动的准确补偿。仿真和实验结果验证了所提的滑模控制方法的可行性和有效性。

Interior permanent magnet synchronous motors(IPMSM)are widely used in aerospace,servo systems,electric vehicles,wind power and other fields because of their high efficiency,high power density,and wide speed range.However,IPMSM has the characteristics of nonlinearity,strong coupling,and variable parameters.It is difficult to obtain fast response speed and strong robustness of the system only by using linear control methods such as PI control algorithm.Sliding mode control is widely used in IPMSM speed control system due to its advantages of strong robustness and fast dynamic response.The frequent switching of switches leads to the control discontinuity,which will bring inevitable chattering to the control system.In addition,a larger load disturbance requires a higher switching gain to ensure the robustness of the system,which will aggravate the chattering of the control system.To address these problems,a sliding mode control for IPMSM speed regulation system based on an improved double power reaching law(IDPRL)and a global fast terminal sliding mode observer(GFTSMO)is proposed.The structure of this paper is as follows.Firstly,the existing problems of sliding mode reaching law,i.e.,exponential reaching law(ERL)and exponential reaching law based on state variables(SVERL)are analyzed.Secondly,the IDPRL based on state variables is proposed.According to the theoretical derivation and analysis,it is shown that the proposed control method has the following characteristics:①the system can converge to the sliding mode surface in a short time,and the convergence time of the proposed reaching law is not affected by the initial value;②the proposed reaching law simultaneously has fast response ability,chattering suppression ability and better anti-interference performance.Thirdly,the IPMSM speed control system based on IDPRL and GFTSMO is designed,and its stability is proved theoretically.Fourthly,the simulation and experimental comparisons are conducted to verify the effectiveness of the proposed method.Finally,the conclusion is presented.The simulation results show that,under the case of the system reference speed of 1000r/min and no load,the speed response time of the proposed IDPRL+GFTSMO method is 80.74%,85.51%and 90.9%of ERL,SVERL,IDPRL,respectively.The steady-state errors of IDPRL+GFTSMO are 32.56%,38.89%and 51.22%of ERL,SVERL and IDPRL,respectively.Under the case of the system reference speed of 1000r/min and the load of 6N·m,the speed drop of the proposed IDPRL+GFTSMO method after loading is 21.54%,24.1%,68.9%and 90.77%of ERL,SVERL,IDPRL,IDPRL+SMO.Under the load torque of 6N·m,the torque ripple of ERL is the largest,the ripple range is 5.33~6.6N·m,and the torque ripple is 21.2%.The pulsation range of SVERL is 5.35~6.6N·m,the torque pulsation is 20.8%.The pulsation range of IDPRL is 5.38~6.46N·m,and the torque pulsation is 18%.The ripple range of IDPRL+SMO is 5.55~6.5N·m,and the torque ripple is 15.8%.For IDPRL+GFTSMO,the ripple range is the smallest(5.6~6.36N·m),and the torque ripple is 12.7%.The experimental results show that,under the case of the system reference speed of 300r/min and no-load startup,the speed response times of IDPRL+GFTSMO,IDPRL,SVERL and ERL are 2.25s,2.79s,3.11s and 3.55s,respectively.The steady-state speed fluctuations of ERL,SVERL,IDPRL and IDPRL+GFTSMO methods are 56r/min,54r/min,51r/min,and 48r/min,respectively.The speed drop scores of the proposed IDPRL+GFTSMO method during loading are 70.58%,72.72%and 84.71%of ERL,SVERL and IDPRL.The speed increase at load shedding is 69.56%,72.73%and 82.05%of ERL,SVERL and IDPRL,respectively.Under the case of the rotational speed from 300r/min to 600r/min,the transient response time of the proposed IDPRL+GFTSMO and IDPRL methods are both smaller than those of the SVERL and ERL methods.Simulation and experimental results show that the proposed method can effectively improve the system response speed,reduce the torque and speed ripple,and improve the anti-interference performance of external loads.