Study On Multi-Mode Rotor Position Detection Technology Of High Speed Pmsm

In Microturbine Power Generation system, high speed PMSM presents two operation modes as motor and generator with a rotating speed of 96000r/min. In the controlling system of high speed PMSM, it's necessary to detect the position of rotor, but it's a difficult step to detect the position of rotor due to the high rotational speed of high speed PMSM. In addition, some traditional methods to acquire the position information are easily affected by the factors such as the condition and can't be applied to detect the position of high speed PMSM. In this paper, research work of multi-mode detection technique was carried out aiming at the problem of detecting the rotor position in the controlling system of high speed PMSM, including the methods of linear hall-effect sensors, reluctance resolver and sliding mode observer, as well as the analysis and study of the adaptability of these three methods in PMSM. First, in order to better carry out research work of position detection, working mechanism of PMSM system was analyzed and mathematical model of the system was deduced. In combination with the structure of PMSM vector control system, the function of position signal in control process was analyzed and method of multi-mode rotor position detection was described.Secondly, the structure of position detection unit and the method of position detection using linear hall-effect sensors were investigated in detail, the existing errors of detection method in practical application were analyzed and specific modified measure was proposed. Position detection circuit was designed on the basis of linear Hall-effect sensors and controlling system of high speed PMSM was established based on the linear Hall-effect sensors. Then experimental study was performed and the properties were analyzed.Once again, the causes of angle error were discussed based on the analysis of working principle of reluctance resolver. Aiming at the problem that output signals of resolver were complex, signal processing system of resolver was mainly analyzed based on the AU6802N1 decoding chip and drive controller of high speed PMSM was developed based on the resolver where relevant experiments were carried out to verify the feasibility of the method.Finally, rotor position detection principle of high speed PMSM was deeply analyzed based on the sliding mode observer and method of exponential reaching law was used to inhibit the inherent chattering phenomenon of sliding mode observer. By MATLAB/SIMULINK tool, simulation model of high speed PMSM sensorless vector controlling system was established based on the sliding mode observer, and validity of the method was verified. Experimental platform was set up based on the TMS320F2812 digital signal processor as controlling unit and experimental study was performed. Experimental results proved this method is feasible.