Operation and analysis of an invertor-fed-linear-motor system

The paper describes a 3-phase system in which a variable-frequency invertor is used to provide speed control of a linear induction motor. The steady-state operation and analysis are considered for invertor operation with two of the six main thyristors triggered simultaneously. The invertor and motor are analysed together, and theoretical results are shown to compare satisfactorily with those obtained experimentally. The comparison encompasses not only r.m.s. values, but also current and voltage waveforms. Results are presented for a published invertor circuit, and for a modified form of this circuit.