| Abstract |
The Dynamic Voltage Restorer (DVR) is a custom power device connected in series with the load, whichcan control the voltage applied to the load by injecting a voltage of arbitrary amplitude, phase andharmonic component into the line. The conventional hysteresis voltage controller of DVR is simpleto implement and has a fast dynamic response etc. However, it suffers from the demerit of variableswitching frequency, which may be prohibitively high, increasing the stress levels on the switches andalso switching losses. In this paper, a ramp based control of DVR is used to achieve a simple closedloop control and constant switching frequency. The method is also extended to a ramp controller withhysteresis to achieve a reduced constant value of the switching frequency. Detailed simulation has beencarried out using PSCAD software. |
