Voltage Sag Mitigation by Using Dynamic Voltage Restorer (DVR)

Due to increasing complexity in the today’s power system, voltage sags and swells are now becoming one of the most critical power quality problems. Voltage sag is a short reduction voltage from nominal voltage, occurs in a short duration of time, they are bound to have a greater impact on the industrial customers. If the voltage sags exceed two to three cycles, then manufacturing systems making use of sensitive electronic equipment’s are likely to be affected leading to major problems. It leads to wastage of financial losses and resources. This is possible only by ensuring that uninterrupted flow of power is maintained at proper voltage levels. Electrical power utilities are looking for solutions to ensure high quality power supply to their customers, a lot of solutions have been developed, but this project tends look at the solving the problems by using custom power devices such as “Series active power filter (SAPF)”. This work describes the techniques of correcting the supply voltage sag and voltage in a distributed system. Among these, the distribution static compensator and the series active power filter (SAPF) are most effective devices based on the VSC principle. The series active power filter (SAPF) injects a voltage in series with the system voltage to correct the voltage sag and swell. Comprehensive results are presented to assess the performance of each device as a custom power solution