PERFORMANCE ANALYSIS OF CAPACITORSUPPORTED DYNAMIC VOLTAGE RESTORER

Dynamic Voltage Restorer (DVR) is installed between the supply and a critical load. It is used to alleviate the power quality problems in terminal voltage such as sag, swell, harmonics, etc. Mitigation of power quality problems using a DVR can be performed by absorbing or injecting the reactive power or the real power or both. However, the amount of active power that can be injected is limited by a number of factors such as stored energy in DC link, different load conditions, finite DVR power rating, and different types of voltage disturbances. In this paper, phase advance voltage injection scheme for dynamic voltage restorers (DVRs) is analyzed with a synchronous reference frame theory (SRF) based control method which eliminates the need of a battery energy storage at the dc link of the DVR. The SRF theory is used for the conversion of voltages from rotating vectors to the stationary frame. The compensation of the voltage sag and swell is demonstrated using a capacitorsupported DVR.