Optimal Harmonic Current Extractor using Digital Warped Filter for a Single -Phase PV Integrated Grid- Tied System with 5-Level DSTATCOM

A new control method for PV integrated single-phase grid-connected 5-level distribution static compensator (DSTATCOM) system is presented and investigated in this paper. It uses a warped digital filter control technique to estimate the fundamental component of load current from the non-linear load. DSTATCOM has been developed using a cascaded multilevel inverter and is used to improve power quality. The proposed system is single-stage, single-phase grid-tied and can operate in two modes viz. During the night, acting as a DSTATCOM unit and performing the necessary shunt compensation while providing additional power to the grid during the day. A conventional Proportional and Integral (PI) controller has been used to regulate the DC link voltages of both capacitors during the sudden variation in solar irradiance and load. Phase shifted PWM scheme has been implemented to generate firing pulses of DSTATCOM. The system is tested under normal and distorted grid conditions. Simulation and experimental results are presented and obtained within stipulated IEEE-519 and IEEE-1547 standards.