Second Order Complementary Sliding Mode Speed Control Of Permanent Magnet Synchronous Motor

With the development of computer technology and power electronic technology,AC servo control technology is more and more widely used in daily life and industrial manufacturing.However,in practice,there are always various uncertainties in the servo control system.The traditional PI control algorithm can not meet the requirements of high precision dynamic and static response of the system.Exploring new robust control strategies has become the focus of current research.Aiming at the speed control of permanent magnet synchronous motor(PMSM),a second-order complementary sliding mode control strategy is proposed to enhance the robustness of the speed loop,weaken the chattering of the output control of the speed controller and improve the response of the current loop.The specific research contents and conclusions are as follows:First of all,sliding mode control(SMC),with its strong robustness,has become the control scheme of choice for this article.The program specifically includes three parts:complementary sliding mode control(CSMC)algorithm;second-order sliding mode control(SOSMC)algorithm and second-order complementary sliding mode compound control(SCSMC)algorithm.The principle and mathematical description of CSMC are elaborated.It is proved that CSMC can reduce the steady state error by at least half compared with traditional SMC.PI control is contrasted,and it is concluded that the CSMC system has strong robustness.However,there is an inherent high-frequency"chattering"in the CSMC system.The robustness of the CSMC is obtained by sacrificing the system chattering.Therefore,weakening the system"chattering"is an urgent problem to be solved.T he SOSMC is the simplest high-order sliding mode.When the relative order of the system sliding mode S with respect to the control input a is 1,the derivative of the input control quantity contains discontinuous switching logic,and the control quantity itself is the integral of the discontinuous switching logic.So the control quantity is continuous,thus eliminating the"chattering" phenomenon.Combined with CSMC and SOSMC,a SCSMC strategy is proposed to meet the strong robustness requirements of the control system and weaken the system chattering.Secondly,the proposed SCSMC strategy is applied to the PMSM speed servo system.The MATLAB/Simulink system simulation model is built according to the basic principles of motor mathematical model and vector control.According to the influence of system parameter perturbation and load disturbance on system performance,the simulation experiment is designed and compared.And results show that the proposed control method weakens the high-frequency "chattering"while improving the robustness of the servo system.Finally,this paper applies the complementary sliding mode control algorithm and the second-order sliding mode control algorithm to the experiment control platform of permanent magnet synchronous motor,and compiles the C language control program to verify the effect of the designed algorithm in the actual system.The experimental results show that the strong robustness of the complementary sliding mode control algorithm and the second-order sliding mode control effectively attenuate the high-frequency"chattering"of the system.