Research For Sensorless Vector Control Of PMSM Based On HF Signal Injection

Due to its characteristics of high power density,high efficiency, simple structure,reliable operation,Permanent magnet synchronous motor (PMSM) has been widely usedin the field of industrial control. For the traditional speed control system, mechanicalsensor increases complexity and cost of the hardware system, and limits its use in somespecial applications. the reliability of the system is difficult to be guaranteed. With thedevelopment of sensorless technology and the microprocessor, high-performancesensorless vector control has a greater and greater application prospect.This thesis proposes a PMSM sensorless scheme for full-speed-range operationcombining the HF signal injection and adaptive observer.First,this thesis deduces themathematical model of motor in different coordinate systems.A method to extract theinformation of rotor position is proposed after analyzing the principle of pulsating-vectorinjection.The structure and working principle of the adaptive observer is introduced, andthe dynamic performance and stability of the system is greatly improved by designing amore reasonable feedback coefficient matrix. Due to that the HF injection method issuitable for working in low speed, and the adaptive observer is suitable for working athigh speed,they are combined by a certain strategy in order to gain a full-speed-rangesystem.A solution for the smooth transition of two schemes is analyzed. Two importantgroups of PI parameters are designed by a practical method which greatly simplifying thesystem debugging process.The influence of the inverter nonlinear characteristics and thesaturation effect on the rotor position estimation precision,and the solutions are analysed.The simulation result, from the simulation platform based on the Saber Designer,provesthe feasibility and effectiveness of the scheme.