Study On Sensorless High-Speed PMSG System With PWM Rectifier Based On LCL Filtering Model

The high-speed permanent magnet synchronous generator has been Widely used in microturbine system due to the advantage of high power factor and small size. However, due to its high speed, while switching frequency is somewhat limited, which led to its generation high current harmonic distortion. This not only reduces the efficiency of the generator's power will also lead to motor heating, aging, Permanent magnet demagnetization, shorting the life span and other issues. In order to obtain high power factor, require accurate rotor position, but the installation of position sensor in high-speed system have some limits such as Location, accuracy and environmental. so This article research on High-speed permanent magnet synchronous generator sensorless PWM rectifier based on LCL filtering model on the generator side.This article first analyzes each in a different coordinate system mathematical model of PWM rectifier. And further more, analyzes the changes and features when series LCL filter. The article analyzes the control strategy of the PMSG-PWM system and the improvements of the high-speed system.In order to obtain high power factor and eliminate position sensors, this paper analyzes the use of SMO in the rectifier system, proposes capacitor current feedback and equivalent total inductance two kinds of methods to establish SMO, when series with filter, and compares the advantages and disadvantages.LCL filter can do better on the suppressing current harmonics, but there are zero-frequency impedances. This phenomenon weakens the filter and threatens the stability of the system operation. This paper analyzes the principle of resonance and study the passive damping and active damping method to suppress the resonant phenomenon. On the other hand, based on the principle of root locus, this paper analyzes the stability of the system using different damping methods and different feedback current.Further more, this paper analyzes the rational design of parameters. Due to the research on the parameters selection limits this paper researches on the selection method of the parameters of the filter and bus capacitor. And then,analyzes the methods of finding PI parameters to meet good system performance. Based on the overall analysis of the system, we established the model of Permanent Magnet Synchronous PWM Rectifier with filter under MATLAB and verified the effect of current filtering, the detection of rotor position and the suppression of resonance. Finally, the paper established a DSP-based experimental platform of digital systems and designed the hardware and software of the system. Through Experiments, this article verifies the feasibility of the system of the position sensor-less high-speed PMSG PWM rectifier based on LCL filtering model.