AUTOMATIC REACTIVE-POWER CONTROL DEVICE Russian patent published in 2000 - IPC

FIELD: electrified DC rolling stock (locomotives). SUBSTANCE: device has load, reactive-power source, supply mains current and voltage sensor, sync pulse unit, pulse-phase control unit, two storage-retrieval units, voltage multiplier, power maximum calculator, frequency divider, and extreme regulation unit. Reactive-power source has series-connected inductance coil, capacitor, and two thyristors connected in parallel opposition; supply current and voltage sensor has potential transformer and current transformer. Load is connected to supply mains through current transformer and parallel circuits of series-connected inductance coil, capacitor, and thyristors connected in parallel opposition; potential transformer is connected in parallel with supply mains and its output is connected to input of first storage- retrieval unit and to that of sync pulse unit. Current transformer output is connected to input of second storage-retrieval unit; outputs of both storage retrieval units are connected to inputs of voltage multiplier whose output is connected through integrator to first input of power maximum calculator. Output of sync pulse unit is coupled through frequency divider with second inputs of integrator and power maximum calculator whose output is connected via extreme control device to input of pulse-phase control unit. Output of the latter is connected to thyristors of reactive-power corrector. Device is designed to raise locomotive power factor by 0.1-0.15 due to correcting load inductive current by capacitive component of reactive-power corrector current which has decreased power requirement by 9-11%. EFFECT: increased power factor and reduced power requirement of locomotive. 1 dwg