| 摘要 |
PURPOSE:To decrease the load current positively upon receiving a conduction stop command even in case of failure in the current control system. CONSTITUTION:The control circuit for a reversible bridge rectifier is constituted of a reverse parallel connection of a separately excited converter 41 comprising a three-phase bridge of self-unextinguishable switch elements and a self-excited converter 51 comprising a three-phase bridge of self-extinguishable switch elements. When a load current is conducted, ON signals are fed simultaneously to a set of converters 41, 51. Upon receiving a conduction stop command, a large firing angle command value not exceeding 180 deg. electrical angle is produced for the separately excited converter 41 whereas a small negative firing angle command not lower than -180 deg. electrical angle is produced for the self-excited converter 51 by an operating unit 2 and ON signals are produced for the converters 41, 51 by firing angle regulators 34, 35 based on the firing angle command values alphap*, thetaN* from the operating unit 2. |
