Enhancement of Power Quality at Low Level Distribution for Non Conventional Energy Source Integrated with Grid System

Non conventional energy sources like Renewable energy resources are being progressively added to distribution systems using power electronic converters. This paper deals a unique control approach for achieving power quality enhancement and maximum benefits from these transmission lines-interfacing inverters when installed in 3-phase 4-wire lower level distribution systems. This inverter is designed to perform multi level functions. Its design t utilize as the active power filter functions. The inverter is also utilized as power injector generated from renewable energy resource. This is also being shunt APF to compensate current unbalance, load current harmonics, load reactive power demand and load neutral current. All these functions may perform either individually or simultaneously. With such unique control, the combination of grid-interfacing inverter and the 3-phase 4-wire linear/non-linear unbalanced lower load at common coupling point appears as balanced linear load to the grid. This novel control concept is demonstrated with extensive MATLAB/Simulink simulation studies and validated through digital signal processor-based laboratory experimental results.