Fundamental approaches to PWM control based GTO inverters for linear synchronous motor drives

High-speed magnetically levitated vehicles require large capacity power converters which supply three-phase sinusoidal current to the armature windings of the linear synchronous motor (LSM). A pulsed width modulated (PWM) inverter using GTOs as a switching device is a promising power converter. Multiplex PWM control has made it possible for inverters to be used for this purpose. A half bridge (HB) and full bridge (FB) are combined with an output transformer. A control procedure for reducing voltage harmonics and preventing magnetic saturation of output transformers is proposed. A case for neutral point clamped inverters is considered and compared with the HB/FB ones.<
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