Static control for a mechanically regulated D-C supply

A new approach to automatic voltage control of a regulating transformer was sought in conjunction with a rectifier transformer and semiconductor rectifying elements connected in a 6-phase double-way circuit. Conventional control for a load tap changer is not designed to detect and correct for fluctuations directly in a d-c line, yet close control of the voltage across the 40-kv rectifier output was required for a radar pulsing station. The alternative of a-c sensing at a point just ahead of the rectifier transformer was considered but this was abandoned due to the problems of reactive drop compensation.