Brushless permanent magnet (BPM) motor drive system using load-commutated inverter

The goal of this work is to develop a brushless permanent magnet (BPM) moto r drive system with low total system cost, high reliability, and adequate p erformance for high-volume production and application to commercial applian ces. The converter used is a low-cost thyristor-based load-commutated inver ter (LCI). Although LCT's have been used to supply the sinusoidally excited permanent magnet motors, their application to BPM motors is a key contribu tion of this work. A detailed digital computer model capable of predicting the steady state as well as the transient performance of the BPM motor driv en by an LCI has been developed, The utility-side phase-controlled rectifie r as well as the motor-side inverter including the de-link inductor are mod eled. A load-commutated inverter specifically designed to supply the BPM mo tor has been fabricated in the laboratory. The developed control strategy h as been implemented on an INTEL 80C196KD microcontroller board. Simulation and experimental results to support the use of an LCI to drive a BPM motor are included in the paper.