Fuzzy Controlled Ultra-Capacitor Based DVR (UCAP-DVR) for Power Quality Enhancement

Abstract

In recent years, a rapid decrease in the cost of various energy storage technologies and their integration into grid becom es a reality with the advent of smart grid. The Dynamic Voltage Restorer (DVR) is a custom power device that ha s an excellent dynamic capabilit y used to provide voltage sag, swell compensation in distribution systems. Among the e nergy storage devices , Ultra-Capacitors (UCAP) have ideal characteristics such as high power and low energy density essential for the compensation of voltage sag and swell , which require high power for short interval of time. This paper presents an integration of rechargeable UCAP with DVR. This UCAP-DVR presents a modular, flexible system configuration that will have an active power capability and also provide deep, extended mitigation for power quality problems. The DVR is integrated into UCAP via bidirectional DC-DC converter which supports a rigid dc-link voltage for DVR and also helps in compensating temporary voltage sag and swell. FUZZY LOGIC Controller is used to enhance the performance of UCAP- DVR. The simulation model for the proposed system has been developed in MAT - LAB and the performance over conventional DVR is compared with the results obtained.