Research On Robustness Of Closed Loop Vector Control For A Permanent Magnet Synchronous Motor

Because of the advantages of high efficiency,simple structure,small size and easy heat dissipation,a permanent magnet synchronous motor(PMSM)has attracted much attention in the field of modern AC speed regulation.The vector control strategy is mostly used due to the better control performance.However,in the process of motor operation,the inaccurate parameters of motor nameplate or the temperature changes will produce the motor parameter deviations,and the load torque and other external disturbances will make the original control parameters hardly achieve the high performance of PMSM.Therefore,how to improve the robustness has become the current research focus.In order to obtain better dynamic response ability,the current prediction control is adopted in this paper.It is obtained by theoretical analysis that the current tracking error will be caused if there is a deviation between the parameters of the controller and the motor parameters.It indicates that the algorithm depends on the accuracy of the motor model parameters.For the above problems,an extended observer is designed to observe the disturbance in real time and the system state,the given voltage of the dq axis is also compensated,and the extended observer is further configured to select the appropriate controller gain.On this basis,the variation range of the parameter deviation of the controller is discussed.The fuzzy PI controller applied to the speed loop is discussed.In order to improve the control precision,the variable domain is used to classify the errors to select different quantization factors so that the control algorithm achieves better robustness.The motor vector control model is built in MATLAB/Simulink,the traditional current predictive control and current predictive control based on ESO and fuzzy PI control have been studied.The parameter deviation caused by the parameters change of the motor or controller is discussed.The designed algorithm is proved by the simulation results,it shows that the algorithm can achieve good robustness for the parameter deviation and torque disturbance and others.The two-level inverter based on TMS320F28069 is built.The experimental platform is composed of a towed loading test platform,and 2.1kW motor is the measured motor.The information of the rotor is obtained by the rotary encoder through the AD2S1210 decoding unit.On the experimental platform,the theretical anlysis is verified,the experimental results show that the system performance is robust under the motor parameter deviation,load torque disturbance and other conditions for the improved algorithm.