Study On The Passive Power Filter In Variable Fequency Drive System Of Permanent Magnet Synchronous Motor

Energy conservation has become the realistic and effective breakthrough point of the adjustment of economic structure, the transformation of economic growth and the increase of economic efficiency with the energy of the growing tensions. The energy consumption of motor is most. Permanent magnet synchronous motor (PMSM) has many advantages, such as low volume, light weight and big torque at low speed etc., so developing PMSM is an important trend to improve the efficiency of the drive system. With the rapid development of the techniques of motor manufacturing, power electronics and microcontroller, the performance of PMSM has made great progress, which promotes it applied in various industry. Variable frequency Drive (VFD) plays an important role in energy saving applications, with the significant contribution in the industry and agriculture, national defense and other field, but it brings noticeable negative influence at the same time. The problems of harmonics at VFD input, common mode voltage and dv/dt interference at VFD output become increasingly serious because of the large scale application of various non-linear load. Therefore, the suppression technology of harmonics, common mode voltage and dv/dt interference has become one of the hot spots which are studied by scholars at home and abroad.In this paper, we did a lot of work to research on the problems above. Firstly it introduces the structure, advantages of PMSM, gives the hardware architecture and control strategies of low voltage, general purpose VFD, and analyze the harmonics, the phenomenon of reflected waves and shaft voltage caused by stray parameters in VFD system of PMSM. The paper points out the essential of the noticeable negative influence, and calculate the THD and the value of common mode voltage according to the literature. Based on the mechanism of harmonics and in PMSM VFD, the paper takes appropriate suppression strategies; and start investigation of the suppression of passive power filter harmonics and interference on the application of passive power filter, including the advantages of passive power filter, the selection of topology, the calculation of the parameters and so on. Depending on the simulation of PSpice, the paper gives the simulation and experimental waveforms which shows the practicability of passive power filter. At last, we did some conclusions of the paper, and discussed the advantages and deficiencies of passive power filter. We also gave some expectations about our research combined with the recent and most popular technologies.