The Research Of The Rotor Position Detection Method For High Speed PMSM

High Speed Permanent Magnet Synchronous Motor(HSPMSM) whose rotor can reach a very high speed itself, has small volume, high speed, little rotary inertia and big power density. So it can omitted mechanical device which is used to increase the speed of the spindle for some filed which need a very high speed. In this way, the system can decrease the vibration and noise, enhance the dynamic property and transmission efficiency. In other words, it can contribute to the energy saving and emission reduction. At present, foreign countries lock the technology of the HSPMSM and our country don’t have HSPMSM product with independent intellectual property rights. Foreign HSPMSM monopolize the internal market completely. Above all, the research on HSPMSM has great practical significance.This paper analyzes the mathematical model of the HSPMSM, and selects sliding mode observer(SMO) and PI model reference adaptive system(PI-MRAS) for simulation after analyzes the common rotor position detection methods with sensor and without sensor. The result of the simulation shows that the SMO has the problem of chattering phenomenon when the motor runs in low speed region and the PI-MRAS has the problem of vibration when the motor runs in low speed region and phase delay when the motor runs in high speed. These problems reduce the detection accuracy of the rotor position. To solute these problems, this paper comes forward the Fuzzy SMO and Fuzzy PI-MRAS. It uses Fuzzy Controller improve the SMO and PI-MRAS. The simulation result shows that the new methods hold-up the chattering of the SMO when the motor runs in low speed region and reduce the vibration of the PI-MRAS when the motor runs in low speed region and phase delay when the motor runs in high speed region compared with the old methodsIn order to verify the correctness and practicability of the new methods, this paper sets up the experimental platform of the 4kW HSPMSM with blower based on magnetic suspended bearings and tests the new methods. The experiment result shows that the chattering of the Fuzzy SMO is smaller than which of SMO in low speed region(about 500r/min). and the Fuzzy SMO can still keep its stability in high speed region(above 20000r/min). For the Fuzzy PI-MRAS, the vibration of the rotor position reduces a lot in low speed region and so does the phase delay in high speed region.