A novel active series voltage compensator with harmonic current compensating capability

A novel unbalance voltage compensator with harmonic current compensating capability is proposed. The proposed system performs both compensations of the unbalanced source voltage and the harmonic currents generated due to nonlinear loads such as diode rectifiers. The operating principle of the proposed system is described through a single-phase equivalent circuit and the control strategy is suggested on the d-q rotating reference frame of the 3-phase system. In addition, a new method for phase angle detection synchronized by positive sequence component under unbalanced source voltage is proposed and this detected phase angle is used for d-q transformation. The proposed system is composed of a 3-phase voltage source converter, LC filter, series transformer and passive device at the load side of the line. The compensating voltage to regulate the load voltage and to remove the harmonic current components at the source side is transmitted to the line by the series transformer.