Flexible control of different power quality problems using UPQC

Abstract EN

In this paper the flexibility of selective compensation is provided in the control scheme of UPQC for different power quality (PQ) problems.

The control scheme of shunt APF compensates the source current harmonics, reactive power and unbalance in source currents and their combinations, while the series APF protects a sensitive load from voltage based distortions.

The proposed control scheme for the shunt APF decompose the load current into positive and negative sequence fundamental frequency active components, reactive component and harmonic components in synchronous reference frame(SRF).

On the other hand, for the mitigation of voltage harmonics, voltage sag, swell and dips, a control scheme based on SRF theory is employed for the series APF of the UPQC.

The control scheme of the UPQC performs with priority based schemes, which respects the limited rating of the VSIs.

In this proposed control scheme of the UPQC, the current / voltage control is applied over the fundamental supply currents / voltage instead of fast changing APFs currents / voltages, there by reducing the computational delay and the required sensors.

The performances of the proposed control scheme of UPQC are analyzed through simulations using MATLAB software with its Simulink and Power System Block set toolboxes.