Power Quality Improvement using Dynamic Voltage Restorer with Hybrid Fuzzy Control Technique

Abstract

Electronic devices function properly as long as the voltage of the supply system feeding the device stays within a consistent range. There are different types of voltage fluctuations that can cause Power quality problems, including, sags, harmonic distortions, surges and spikes and momentary disruptions, nonstandard voltage, current or frequency that results in a failure or miss operation of end user equipment. The steady-state PQ characteristics of the supply voltage include surges and spikes. Voltage sags and swells are the common events on the electric power network. Voltage sags and swells are the common events on the electric power system. The common causes of voltage sag are short circuit or faults in power system, at starting of large loads and faulty conductor. These problems can be mitigated with voltage injection method using custom power device, Dynamic Voltage Restorer (DVR).A DVR is connected in series with the linear load to compensate for the harmonics and unbalance in the source voltages and improve the power factor on the source side. A series connected converter based mitigation device, the  Dynamic Voltage Restorer(DVR), is the most economical and  technically advanced mitigation device proposed to protect  sensitive loads from voltage sags. In this paper, DVR which consists of injection transformer, filter unit, Pulse Width Modulation (PWM) inverter, energy storage and control system is used to mitigate the voltage flickers in the power distribution system. Here we propose two control techniques which are the Proportional Integral (PI) Controller and Fuzzy Logic (FL) Controller. In this Project we are design a Dynamic Voltage Restorer (DVR) with Proportional Integral (PI) Controller and Fuzzy Logic (FL) Controller, to improve power quality in power system by using. In extension proposed DVR is subjected to operate under hybrid fuzzy logic controller using Matlab/Simulink software.