3상 전압형 인버터 구동용 전력변환회로 설계에 관한 연구

Abstract

In recent years, with the development of power conversion circuit topologies using MOS gate controlled power semiconductor devices such as MOSFETs and IGBTs, and the increase in switching frequency of the inverter and converter, the controllability of the converter and undesired sound reduction and converter downsizing are achieved.

Although, in the conventional hard-switching PWM semiconductor power conversion circuit systems, the increase of switching losses in the power semiconductor devices which is caused by the overlapping period of the voltage and the current in the switching power devices required big heat sink and these are becoming hot issue in power electronic industrial field.

In addition to these, the conductive and radioactive electromagnetic noise arise due to the switching surge which results from dv/dt and di/dt. Moreover, in the inverter or converter which is applied to the variable speed AC motor or servo drives, high frequency leakage current which flows into the ground line through the stray capacitance among the stator winding frame of the motor, and the motor shaft voltage and the bearing current are another problems

A basic solution for these problems are the soft switching and its related control techniques of the power converter which turn on and off the power semiconductor devices under zero voltage or zero current mode transitions using the active auxiliary quasi-resonant snubber. So far some circuit topologies have been proposed for the three phase voltage-fed soft switching inverter circuit such as quasi-resonant DC link, quasi-resonant AC link and auxiliary quasi-resonant commutation pole.

In this paper, a new topology of boost PWM DC-DC converter is proposed and its operating principle is described on the basis of simulation and experimental results. And also auxiliary active quasi-resonant DC link snubber for the soft switching three phase voltage-fed inverter system is discussed here and evaluated for the soft switching of the quasi-resonant snubber circuit. A conductive noise of the three phase voltage-fed inverter using this quasi-resonant snubber is measured for permanent magnet (PM) motor drive, and it is compared with that of the conventional hard switching three phase inverter.

Through a series of computer simulations and experiments, the effectiveness of the newly proposed and designed boost PWM DC-DC converter is confirmed.