GTO choppers for rail vehicles

Digitally controlled GTO choppers are now the norm for all new DC EMU equipment. This change represents a revolution in the design of propulsion equipment as dramatic as the introduction of power semiconductor devices in the 1960s. The author discusses seven recent designs of choppers using gate turn off (GTO) thyristors. Details are given of three designs that are being introduced into fleet operation on British Rail, Hong Kong MTRC and the London Docklands Light Railway.<
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