Adaptive balancing compensator

Reactive power compensators with thyristor switched inductors and shunt capacitors enable adaptive compensation at the price of an harmonic distortion increase. This distortion is even higher if the compensator is controlled asymmetrically to reduce the effects of the load unbalance. Harmonic distortion may increase, moreover, because of the compensator resonance with the supply system reactance. This paper suggests a modification of the balancing compensator structure that reduces the harmonic currents injected by the compensator into the supply. The structure suggested also reduces the possibility of the compensator resonance with the supply source inductance. The paper discusses the required control range of the compensator susceptances and their frequency properties and suggests an efficient method of measuring the load parameters needed for VAr compensator control.>