Power quality enhancement in a distribution system using inductive active filtering technique

Abstract

In this Paper a new converter transformer using inductive active filtering technique are suggested to solve the prevailing problems of the traditional converter transformer with the active filtering method in the distribution system. The distribution network provides power supply to various kinds of non-linear loads like three phase rectifier fed motor drives and high power industrial electrolysis. Generally a converter transformer is used in the rectifier and inverter station. The harmonic components from the nonlinear load flows easily into the winding of the transformer, which decreases the life time of transformer and it also brings PQ problems to the distribution network and the supply system. To overcome this problem an inductively filtering method was proposed in this paper. A tap at the connecting point of the transformer secondary prolonged winding and the secondary common winding is associated with the filter circuit. When the harmonic current goes into the secondary prolonged winding, the common winding of the new converter transformer will make the contrasting harmonic current to balance it by the zero impedance design of the secondary common winding, so there will be no induced harmonic current in the primary winding of the new converter transformer. Performance of Inductive active filtering method is very effective compared with traditional shunt active power filtering method.