Distributed Generation Interconnection with Improved Unified Power Quality Conditioner for Power Quality Mitigation

This paper presents the results of the integrated operation of the Improved Unified Power Quality Conditioner with distributed generation of photovoltaic (I-UPQCPV). The 1-UPQCPV supply power from the PV through the shunt inverter to the load, which result into the high Volt-Amp (VA) loading on the shunt inverter. Hence, the power angle control approach aims at the adequate utilization of series and shunt inverter by proper coordination of imaginary power sharing between the two inverters to reduce VA loading on shunt inverter. In this arrangement, DC-link is connected to the generator with the application of the rectifier. The UPQC consist of series and parallel voltage source inverter (VSI) connected back to back with the same DC-link with DG to mitigate under-voltage, overvoltage and interruption. The execution of the proposed system is tested with nonlinear loads connected system with PV solar generation. The effective operation of the system is confirmed during grid disturbance such as sag/swell and interruption. The execution of this work was performed using Matlab/Simulink. The investigation of this approach indicates that (I-UPQCPV) maintain the load voltage within the permissible limit of ±5 % during disturbance.

I. Introduction

The power system is charged with the responsibility of production, transmission, and distribution of electrical energy to end-users in a dynamic, adequate, economical, and reliable level. Some critical situations in the operation of the power system network for the transmission and distribution level required to be considered in designing a new network and in major expansion of existing networks to determine its performance. These consist of a rapid voltage rise, electrical loss, voltage regulation, distribution plant loading, voltage fluctuations, harmonics and stability. Sustaining the voltage and frequency level at (±5% voltage and±1%frequency) standard limits at the end user's terminals is a big challenge for distribution companies (DNO) [1].