Research On The Control For Permanent Magnet Synchronous Motor Without Position Sensorless In Full Speed Range

The permanent magnet synchronous motor(PMSM)speed regulation system is applied more and more widely,which in new energy vehicles,ship power,CNC machine tools and other fields.Sensorless control can reduce equipment manufacturing costs,enhance system reliability,has a wide range of application value.The permanent magnet synchronous motor without position sensor is one of the main development trends.High order current harmonics in the operation of permanent magnet synchronous motor speed regulation system.The high order harmonic current increases the loss and generates torque ripple,which reduces the system performance.The current harmonic suppression control technology of PMSM has become a research hotspot.In this paper,a speed regulation of sensorless PMSM with current harmonic suppression is proposed,which can work in full speed range.Based on the complex vector cross coupling decoupling PI current controller is applied in each harmonic current synchronous rotating coordinate system.The current harmonic is suppressed and the coupling term with the change of speed in the equation of permanent magnet synchronous motor is eliminated,make the complex vector PI current controller can suppress current harmonics at different speeds.The mathematical model of PMSM considering higher order current harmonics is established,and the complex vector PI current regulator is constructed.Under the coordinate system of synchronous rotation of high order current harmonics,the fifth,seventh,eleventh and thirteenth harmonic components in the phase current of PMSM are suppressed,and the harmonic loss and torque ripple are reduced.A position estimation method for speed regulation system of PMSM without position sensor is presented.In the estimation rotor coordinate system,based on i_?=0 vector control system for interior permanent magnet synchronous motor(IPMSM)is designed.In the medium-high speed range,the rotor position and speed are estimated by the extended electromotive force and the phase-locked loop observer in the estimation coordinate system.In the low speed range,the rotor position and speed are estimated by high frequency square-wave-type signal injection method and observer.In the static state,based on convex polarity of IPMSM and principle of magnetic circuit saturation,the polarity of magnetic pole is identified to realize the position and speed estimation and control within the full speed range of the permanent magnet synchronous motor.High-precision harmonic current suppression control improves the accuracy of rotor position estimation based on mathematical model method at different speeds.Through MATLAB/Simulink software,the vector control model was built for simulation experiments,and the rotor position estimation method in the full speed range of medium?high and low speed was verified.For the sensorless control system with complex vector PI current controller used to suppress current harmonics in the whole speed range under the estimated rotor coordinate system,the effectiveness and feasibility of the proposed scheme are proved by comparing the current waveforms before and after suppression.