ISSN 2394-3777 (Print) ISSN 2394-3785 (Online) Available online at www.ijartet.com International Journal of Advanced Research Trends in Engineering and Technology (IJARTET) Vol. 6, Issue 7, July 2019 All Rights Reserved © 2019 IJARTET 1 PV based Hybrid Multilevel DVR with SVPWM for Power Quality Improvement S. RUPASRI 1 , Dr.G. ANNAPURNA 2 1 PG Scholar, Dept of EEE, G. Narayanamma Institute of Technology & Science (For Women), Shaikpet, Hyderabad, TS, India, (E-mail: -sangarupasri345@gmail.com) 2 Associate Professor, Dept of EEE, G. Narayanamma Institute of Technology & Science (For Women), Shaikpet, Hyderabad, TS, India, (E-mail: gootyanu@gmail.com). Abstract: In this paper the power quality disturbances such as voltage sag, swell is mitigated by using a custom power electronic device, Dynamic Voltage Restorer (DVR) which is of seven level multilevel inverter composed of Capacitor Clamped and Cascaded H-bridge topology. The DC link capacitor of the Hybrid Multilevel Dynamic Voltage Restorer is supplied by the PV panel to compensate any voltage deviations that occur in a system caused by power quality issues .The Hybrid Multilevel configuration presented has many advantages over conventional multilevel inverter and the PWM pulses to the inverter are given by Space Vector Pulse Width Modulation (SVPWM) .Simulations are carried out in MATLAB/SIMULINK software in order to evaluate the performance of Photovoltaic fed DVR in mitigating the voltage disturbances .The Simulation results show that the proposed multicell inverter provides different levels of output voltages and high modularity and the study also shows that Space Vector Modulation is more efficient in reducing the Total Harmonic Distortions. Keywords: DVR, Sag, Swell, Harmonics, Photovoltaic array, SVPWM, SPWM. I. INTRODUCTION Present days power quality issues are becoming major problems in over distribution system, in order to get constant load voltage power quality issues are to be mitigated. However, especially in the distribution systems, having more nonlinear loads which are significantly affecting the quality of the power supply. Because of these nonlinear loads, the purity of the supply waveform is disturbing. This ends up producing power quality issues [1]. Voltage sags (dips) are defined as one of the most frequently occurring power quality problems. The reduction in voltage magnitude between 10% to 90% compared to nominal voltage from half a cycle to a few seconds are termed as voltage sags. There are different ways to mitigate voltage dips in power quality systems. Among those, the dynamic voltage restorer (DVR) is the most effective device, based on the voltage source converter (VSC) principle [2]. Swell is opposite to that of a Sag, having an increase in AC Voltage for a voltage magnitude greater than 110% of the nominal voltage. Usually swells are caused by abrupt switching of heavy loads which leads to transients, interruptions and complete collapse of the system etc. The definition of a harmonic is “a sinusoidal component of a periodic wave or\ quantity having a frequency that is an integral multiple of the fundamental frequency.” i.e. a pure sine wave in terms a clean power waveform without any harmonics. This paper is structured as follows: Section II describes briefly the operation of DVR. Section III presents the principle of operation of Hybrid Multilevel inverter. Section IV presents PV fed DVR model. Section V presents Space Vector Pulse Width Modulation (SVPWM). Section VI represents results of multilevel DVR and the output results and conclusion in Section VII. II. OPERATION OF DVR The DVR can mitigate the load voltages from the problems such as sag, swell, and harmonics that are produced in the supply voltages. Hence, it can protect the critical consumer loads from tripping and consequent losses. [9].