An Improved Compensation Technique using DVR for Power Quality Improvement in Distribution Power System

This paper presents an enhanced a-b-c frame theory for the generation of reference compensation voltage of the three-phase Dynamic voltage restorer (DVR) based Series Active Power Filter(SAPF) under non ideal conditions like unbalanced and distorted source voltages (non-sinusoidal) in steady-state. The proposed method is very simple and easy to implement which is strong enough to compensate for the voltage-related power quality (PQ) problems in the power systems such as voltage sag, voltage swell, harmonics and voltage unbalance. The compensating device injects voltage in series by a three-phase Voltage Source Converter (VSC) with a variable hysteresis voltage control mechanism. This method mathematically proves that in the steady-state condition the DVR consumes or supplies zero average/null active power. The proposed strategy is validated in Matlab/Simulink and the simulation outputs demonstrated its effectiveness and efficiency.