FIELD: digital control systems for valve-type converters; three-phase controlled rectifier bridges using microprocessor control systems. SUBSTANCE: primary synchronizing voltage is shaped as difference of any two line voltages across converter input. This eliminates commutation dips in voltage obtained caused by connection of pair of thyristors related to one phase irrespective of control angle. Region free from commutation dips is provided in primary synchronizing voltage obtained; width of this region depends on regulation range of converter control angles. Primary synchronizing voltage obtained is filtered off to obtain final synchronizing voltage. Phase shift of the latter provides for locating zero crossing point in region free from commutation dips. At maximum phase shift of 150 el. deg, regulation range of converter control angle is 0 to 120 el. deg. Minimum phase shift corresponds to sum of maximal control angle and 30 el. deg. EFFECT: improved synchronization accuracy and reliability at heavy distortions of supply voltage. 2 dwg
