Double Stage Solar PV Array Integrated UPQC for Three Phase Four Wire Distribution System

The double stage solar photovoltaic (SPV) array integrated four wire unified power quality conditioner (UPQC) system is presented for three phase four wire distribution network. The control of four wire UPQC-PV system is done to eliminate the voltage and current power qualities (PQs) problems like neutral current, harmonics, reactive power, voltage sag, voltage swell, voltage unbalanced, etc. The four wire UPQC-PV system consists of two four legs voltage source inverters (VSIs) connected back to back through common DC- bus. The four wire UPQC-PV system is modelled in the Simulink/MATLAB, and its results are presented for analysis for various instances, unbalancing of load, unbalanced voltage sag and swell, solar irradiation variation, etc. The system performs effectively for such conditions and the current and voltage PQs problems are simultaneously improved. The load side voltages and the grid currents total harmonic distortions (THDs) are within the limits of the IEEE-519 standard.