Study of Soft Switching Converter for Switched Reluctance Motor Drive

Abstract

Switched reluctance motor (SRM) has become a competitive selection for many applications of electric machine drive systems recently due to its relative simple construction and its robustness. The advantages of those motors are high reliability, easy maintenance and good performance. The absence of permanent magnets and windings in rotor gives possibility to achieve very high speeds (over 10000 rpm) and turned SRM into perfect solution for operation in hard conditions like presence of vibrations or impacts. Such simple mechanical structure greatly reduces its price. Due to these features, SRM drives are used more and more into aerospace, automotive and home applications. The major drawbacks of the SRM are the complicated algorithm to control it due to the high degree of nonlinearity, also the SRM has always to be electronically commutated and the need of a shaft position sensor to detect the shaft position, the other limitations are strong torque ripple and acoustic noise effects. The purpose of the thesis is to design, develop, implement a soft switching converter topology using insulated gate bipolar transistor (IGBT) suitable for switched reluctance motor. Research being done in field of switched reluctance motor including soft switching converter is discussed. The validity of the topology is verified through MATLAB simulation. Results are presented and comparison is made between converter topology using metal oxide semiconductor field effect transistor (MOSFET) and converter topology using insulated gate bipolar transistor (IGBT). Conclusions are drawn regarding the effectiveness of proposed converter topology. The novel topology is presented and the principle of operation is described in detail. The use of insulated gate bipolar transistor (IGBT) have enabled better switching performance than the metal oxide semiconductor field effect transistor (MOSFET) in medium to high power applications due to their lower on-state power loss and high current densities.