Research On PMSM Control Algorithm Based On Improved High Frequency Injection Method And Sliding Mode Observer

Permanent magnet synchronous motor,with its simple structure,high power density,high efficiency and outstanding performance characteristics,has become an important power source of high speed motorized spindle grinding system,high speed centrifugal air compressor and other transmission systems.Either high speed motor or conventional motor drive control system,the accurate position and velocity of the motor rotor are the prerequisite to realize the field oriented vector control of PMSM.In high speed machinery,the position sensor used to measure the rotor position and speed of the motor will bring safety risks,new failure points and cost problems,and the installation position is limited.These limit the application of high speed permanent magnet synchronous motor.Therefore,this paper studies the position sensorless field oriented vector control technique of PMSM,the main research works and achievements are as follows:1.A control algorithm of permanent magnet synchronous motor based on improved high frequency pulse vibration voltage injection method is proposed.The improved high frequency pulse vibration voltage injection method is proposed,and the high frequency pulse vibration voltage is injected into the direct axis of the dq coordinate system.By analyzing the αβ axis component of the stator current instead of the dq axis component,the rotor position signal is obtained.It solves the problem that the convexity polarity of the motor is not obvious in the traditional control method.The stator current αβ axis component is modulated directly and the rotor position signal is obtained through the low pass filter.The indispensable bandpass filter is removed,the system structure is simplified,and the dynamic control performance of the system is improved.2.A control algorithm of permanent magnet synchronous motor based on improved sliding mode observer is proposed.Because of the switching function of the control system,the system structure has a time varying switching characteristic,which makes the control of the system discontinuous,resulting in the high frequency chattering problem of the sliding mode control in the sliding mode.However,the high frequency chattering problem of the traditional sliding mode observer control system based on sign symbol function is particularly serious due to the high frequency switching of the system structure.The improved sliding mode observer,which uses piecewise exponential function instead of the sign symbol function used in the traditional sliding mode observer,can effectively reduce the high frequency chattering,and the motor rotor position and velocity estimation accuracy is higher,and the control system is more stable.3.By combining the improved high frequency pulse vibration voltage injection method with the improved sliding mode observer,complementary advantages,the rotor position and velocity observer within the full speed range of PMSM are established.In order to realize the smooth handover of the control algorithm,a new handover strategy is proposed.It uses the exponential weighted function α to realize the smooth handover from the improved high frequency pulse vibration voltage injection method to the improved sliding mode observer.4.A simulation model of PMSM control algorithm based on improved high frequency pulse vibration voltage injection method and sliding mode observer is established on MATLAB/Simulink software platform.The simulation results show that the proposed control algorithm solves the problems existing in the traditional control algorithm and the control effect is good.Experiments on the hardware platform with TI’s TMS320F28335 DSP as the core verify the effectiveness and feasibility of the proposed control algorithm.