MICROPROCESSOR CONTROL OF LINE COMMUTATED INVERTER FED INDUCTION MOTOR DRIVE

Abstract

The line commutated inverter and synchronous motor system have the characteristic of a D.C. motor. This combi-nation is popularly known as the commutatorless D.C. motor. The LCI-SM system can be used as a variable frequency source for induction motor Drive. In the present thesis work the line commutated inverter has been fabricated and a microcomputer based firing scheme has been developed. The steady state perfor-mance characteristics of the LCI-SM system have been obtained using both analog and microcomputer based firing scheme. Finally,the feasibility of microcomputer controlled LCI-SM system as a variable frequency source for induction motors has been experimentally investigated. From extensive tests carried out on the experimental setup of LCI-SM-IM system, it has been observed that the LCI-SM system works satisfactorily as a variable frequency source. The microcomputer control improves the system performance of the system by improving the stability and reliability of firing pulses.