| Under the background of the rapid development of power electronictechnology, new motor drive, permanent magnet synchronous motors(PMSM) have developed rapidly and promoted to use. The feedbacksignals of speed and rotor position are essential. Usually, the positionsensor is installed in the PMSM to measure mechanical position of therotor and the rotor speed. However the installation of the position sensorbrings a lot of disadvantages: Volume of the motor increases, which isincrease the cost of the control system. Sensorless control could eliminatethe effects which are caused by the installation of position sensor. Theissue is from Shanghai Electric Center Academe and based on Mywaycontrol system. In this paper, theoretical analysis and simulation modelsare analyzed. And algorithm is improved to calculate the rotor position androtor speed with mathematical model. It achieves the closed-loop controlof PMSM. The main research of this paper is as follows:Firstly, it introduces the basic structure and classification of PMSMspecifically. And it also describes the equations of PMSM incoordinates. On this basis, the motor vector control method is discussed.Use the space vector modulation (SVPWM) control technology for motordrive control system. It also analyzes the principle of SVPWM control indetail; and deduces the theoretical formula. According to the formula,PSIM simulation model is established.Secondly, the basic principle of high frequency injection method andsliding mode control (SMO) is introduced in detail. And a hybrid controlstrategy is proposed, namely the high frequency injection method and SMO are combined in the sensorless control system. It also built a functionof average speed so that it could achieve switching smoothly. In the highspeed range, reasons of buffeting of SMO are analyzed in the theoreticalanalysis. And apply SMO motion to the dynamic performance control ofthe motor. Adaptive sliding mode observer is structured to obtain the rotorspeed and position. In the low speed range, in this paper, high frequencyinjection method is used when motor is in the low-speed range to achievethe sensorless control. High-frequency signal could contain information ofmotor’s position and the speed, which is extracted through the design ofeffective filters. To resolve the problem-phase delay, an improved structureis designed that phase locked loop is combined with heterodyne to obtaininformation of rotor from the response current of the motor.Finally, according to the theory and PSIM simulation of PMSM, theexperimental verification of control theory is in progress by using theMyway control system, DSP programming. |
