Gain compensation for power factor in line current regulating systems involving reactive power

摘要

In an alternating current electric power system of the type subject to rapid load voltage regulation as a result of variations in reactive load current, reactive load current compensation is provided by fixed capacitors and inductors in parallel with the load, the inductors being in series with static switches which are phase controlled to continuously maintain the net reactive compensating current substantially equal and opposite to the reactive component of load current. Compensation control determines firing time of the static switches in accordance with the magnitude of reactive load current. Regulating means additionally controls firing time to maintain line current and line to neutral voltage at a selected line location substantially in phase coincidence. The regulating means is provided with means for enhancing the stability of the system under no load or light load conditions. In a preferred embodiment, regulation stability is enhanced through the application of a small real or, in phase current signal whenever the real or in phase component of actual line current at the selected line location is less than a predetermined level which is desirable for stable regulation of the power system.