Voltage Dips and Mitigation System using Dynamic Voltage Restorer

Quality of the output power delivered has become a major concern for heavy
duty industry for present era. The poor power quality is due to some disturbances
such as voltage sags/dips, surge, flicker, harmonics, imbalance and interruptions. It
becomes more important especially with the sophisticated devices whose
performance is very useful to the quality of power supply. Power quality problem in
industries, factories, university, residential areas etc cause failure to the equipment
and malfunction which can make the operating system stop and at the end gives a big
impact to the plant production. These issues become worse if there is no mitigation
system to counter back the problem. A voltage dip is loss of rms voltage which is a
major power quality problem. In specific term of duration and retained voltage, it can
also be representing as the lowest rms remaining voltage at the lowest point during
the dips at the industry. So, it is the responsibility of the user and customers to
identify the root cause of the problem and create a mitigation system to overcome the
problem. To overcome this abnormal problem custom power devices are connected
closer to the end of the load. One of the devices is the Dynamic Voltage Restorer
(DVR) which is the most efficient custom power device used in power distribution
networks. This paper presents modeling, simulation, and analysis of a Dynamic
Voltage Restorer (DVR) using PSCAD (Power System Computer Aided Design)
software. The main component of a DVR is voltage source converter (VSI) which is
operated by pulse width modulation (PWM) technique and a PI controller. There are
many different type of fault has been created and shown reliable result after mitigate
usingDVR