DSP Algorithm based Enhanced Phase Locked Loop Scheme for DSTATCOM

This paper deals with Enhanced Phase Locked Loop Control scheme for Distributed Static Compensator (DSTATCOM) in the distribution system. The proposed control scheme based DSTATCOM eliminates current harmonics, maintains unity power factor at source, zero voltage regulation and load balancing. The Enhanced Phase Locked Loop (EPLL) Control scheme is based on Digital Signal Processing (DSP) which is used to extract fundamental component of active and reactive currents for generation of reference source currents. The DSTATCOM consists of sixleg based voltage source converter (VSC) which uses unipolar switching which doubles the switching frequency and reduces size of the filtering circuit. The zig-zag/three singlephase transformers reduce DC bus voltage and acts as a neutral current compensator. The proposed control scheme for six-leg DSTATCOM is modeled and validated in MATLAB R2012b by using simpower systems toolbox. Keywords–Distributed static compensator (DSTATCOM), unity power factor, zero voltage regulation, enhanced phase locked loop (EPLL), distribution system, resonant converter, simulation, ac analysis.