A series voltage compensator based on thyristor-controlled transformer

Series compensation is an important way to improve transmission capability and power controllability of long-distance power delivery systems. Since typical series compensators have some limitations, this paper proposes a novel series voltage compensator based on thyristor-controlled transformer. By special configurations of transformer windings and thyristor converters, it is capable of injecting voltage phasors with adjustable magnitudes and phase angles. Taking the advantage of power semiconductor devices, this compensator responds much faster than mechanical compensators and permits frequent regulations. A SMIB system with two parallel transmission lines are taken as a study case. And simulation results show the injected voltage and regulated power by the compensator, which proves its effectiveness.