Special Issue Article
To Mitigate the Voltage Sag Using Diode Clamped Multi Level Inverter with DVR Technique
In this paper a Dynamic Voltage Restorer (DVR) based on a multi level inverter with energy storage devices is proposed. It describes the problem of voltage sag and swells and its severe impact on non linear loads or sensitive loads. The dynamic voltage restorer (DVR) has become popular as a cost effective solution for the protection of sensitive loads from voltage sags and swells. The control of the compensation voltages in DVR with diode clamped multilevel inverter and PDPWM technique is proposed. Multilevel inverters have become more popular over the years in high power electric applications without use of a transformer and with promise of less disturbance and reduced harmonic distortion. These Pulse Width Modulation (PWM) techniques include Carrier Overlapping (CO) strategy, Variable Frequency (VF) strategy, Phase Shift (PSPWM) strategy and Sub-Harmonic Pulse Width Modulation (SHPWM) i.e. Phase Disposition (PD) strategy, Phase Opposition Disposition (POD) strategy and Alternate Phase Opposition Disposition (APOD) strategy. The Total Harmonic Distortion (THD), VRMS (fundamental), crest factor, form factor and distorti on factor are evaluated for various modulation indices. Simulation is performed using MATLAB-SIMULINK.