PHASE CONTROL METHOD Russian patent published in 2003 - IPC

FIELD: converter engineering; pulse- phase control of thyristor converters. SUBSTANCE: method depends on charging the capacitor of relaxation-generator synchronized with supply mains through resistor up to operating voltage of threshold device; operation of the latter yields signal for shaping power-thyristor control pulse and capacitor is charged with minimal current corresponding to maximal control angle; in the process electromotive force adjustable between zero and operating voltage of threshold device is introduced in series with capacitor charge circuit; this emf is added to voltage across capacitor and determines level of its charge required to set up threshold- device operating voltage and, hence, control angle; emf is introduced by connecting either variable resistor using its voltage due to capacitor charge current as emf or resistor supplied with adjustable emf from external source in series with capacitor; resistor is chosen of rating ensuring that current it carries were higher by 5-10 times than capacitor charge current to eliminate impact of this current on emf being introduced. EFFECT: enhanced control range at amplitude phase control; reduced power requirement and control power. 3 cl, 2 dwg