Research On Rotor Position Self-detection Method Based On Permanent-magnetic Synchronous Motor

In recent years, with the emergence of high performance permanent magnetic material andthe rapid development of power electronic technology and motor control technology, permanentmagnet synchronous motor (PMSM) is widely used in Various kinds of ac speed regulatingoccasions, such as: civil, industrial, and military etc.Commonly used motor control methodsarevector control and direct torque control, both of two methods require real-time detecting of rotorposition information. And the use of mechanical position sensor to detect the rotor position willusually increase the project cost, reliability, generally is not high also, for air conditioningcompressor, refrigerator compressor and fan, water pump drive system and so on some occasions,the working environment is poor, limit the use of mechanical sensor. So this article is eager toadopt the method of software estimation to replace mechanical sensor to test the rotor position.Based on sine wave driven permanent magnet synchronous motor as the research object, throughthe simulation and experiment of two kinds of permanent magnet synchronous motor drivecontrol system of sensorless rotor position detection is studied.Main contents and conclusions:First of all, in the static and dynamic system established the mathematical model ofpermanent magnet synchronous motor, in-depth study the working principle of the sliding modeobserver is to improve the traditional sliding mode observer, the introduction of motor back emfcoefficient, design a new type of sliding mode observer.Secondly, set up in MATLAB/simulink current and speed double closed loop control systemsimulation model of a new sliding mode observer in the relevant simulation research is carriedout on the simulation model, mainly including:(1) the stability simulation analysis (for theelectric and mechanical and electrical parameters and mechanical parameters influence on thestability analysis).(2) a new sliding mode observer observing performance simulation analysis;(3) the potential of feedback coefficient introduced the simulation analysis. Simulations showthat：compared with the traditional sliding mode observer, a novel sliding mode observer canexpand the range of speed in a certain extent, improve the running position sensor algorithmwhen the motor speed performance. The introduction of back EMF feedback suitable coefficientcan effectively reduce the estimated delay, reduce the rotor position estimation error. A novel sliding mode observer in motor running speed in the range of25r/min~3000r/min and accuratelyestimate the rotor position of permanent magnet synchronous motor.25r/min rated parameters ofno-load operation of rotor position estimation error of-8degrees~4degrees,3000r/min ratedparameters of no-load operation, rotor position estimation error range of-4.2°~4.5°.Finally, TMS320F28335DSP of TI company as control core, motor drive system for thehardware design, and on the platform to write the vector (SVPWM) control and sliding modeobserver algorithm, finish the software design of motor drive system. Experiment shows thatAnew sliding mode observer has favorable observation performance in high speed, low speedperformance is considerable, reached a minimum of rotor position error estimate given speedwhen300r/min3degrees~5degrees, the given speed1200r/min, minimum estimation error canreach6DEG rotor position, speed running experiments show a novel sliding mode observer foranti disturbance performance is good, the speed of mutation when there are observations of verygood performance, the experimental results and simulation, the basic realization of rotor positionin high speed motor without position sensor self detection.