Certain investigation on power quality issues in transmission and distribution system using pso technique

Abstract

The primary responsibility of the power distribution systems is to provide uninterrupted flow of energy at smooth sinusoidal voltage at the desired magnitude level and frequency to the consumers. The reliability and cost of any electrical system depends greatly on the quality of the power supplied and consumed by the system. So it is important to maintain the power quality as high as possible. But power quality issues are created in power systems especially in the power distribution systems are due to the non-linear characteristics and fast switching of power electronic equipment. This issues increase with the increase of wide usage of sensitive equipment consists of nonlinear loads and power electronic loads which introduces harmonics into the system. These harmonics also cause interference in the nearby communication system. Some of the power quality issues like harmonics, voltage sag, swell and unbalance are resolved here by one of the custom power devices which is used to increase the quality and reliability of the power delivered to the consumers. The concept of custom power devices is to use power electronic or static controllers in the low and medium voltage distribution system. Some custom power devices are Dynamic Voltage Restorer (DVR), Distribution Static Synchronous Compensator (DSTATCOM) and Unified Power Quality Conditioner (UPQC). In this thesis, a UPQC based on voltage source converter and current source converter is designed to mitigate power quality problems. The real power supply is given by the Photo Voltaic (PV) system for the compensation of power quality problems. The reference current and voltage generation for shunt and series converter of UPQC is based on Phase Locked Loop (PLL) and Synchronous Reference Frame (SRF) theory. Simulations have been carried out in MATLAB Simulink platform. The simulation results for Particle Swarm Optimisation (PSO) tuned UPQC followed by Current Source Converter (CSC) based UPQC are presented. newline