Performance Improvement of a Distributed Generation System Using Unified Power Quality Conditioner

This paper deals with performance improvement of a distributed generation (DG) system using unified power quality conditioner (UPQC). Despite of the several benefits of DG like excellent energy supply, reducing expansion of power distribution system, environmental friendly and so on, there are several challenges existing due to the integration of DG with the grid or operating it in standalone mode. Power quality (PQ) issue is one of the main technical challenges in DG power system. Moreover, harmonic and voltage sag compensation in a DG networks has significantly reduced PQ, which affects the stability of the system. Hence, in this paper, impact of PQ issues in an adopted standalone DG system (comprising of solar, wind and fuel cell based renewable energy sources) is investigated in the presence of UPQC. The realization of UPQC is carried out using conventional synchronous reference frame (SRF) and modified SRF (MSRF) techniques for reference current generation with pulse width modulation voltage source inverter technique for generation of pulses for the inverter along with a PI controller for regulation of DC-link capacitor voltage. The voltage sag compensation with current and voltage harmonics are estimated at different source (ideal and non-ideal) conditions with different control scheme like SRF and MSRF technique. The simulation model of conventional SRF and MSRF technique based UPQC is developed under MATLAB/SIMULINKR environment. The result obtained validates the superiority of proposed technique over others in terms of harmonics elimination and sag compensation.