Mitigation of voltage sag/swell with CSI-IDVR

The distribution system contains various types of loads. These loads can be broadly classified as sensitive loads and non-sensitive loads. The sensitive loads are easily affected with power quality problems. Hence, power quality improvement is major concern in the distributed system. The power quality problems that are faced in the distribution side are voltage sag/swell, harmonics, flickering, distortions etc. One of the major power quality issue that is considered in this paper is voltage sag/swell. To handle these power quality issue Flexible AC Transmission Systems (FACTS) devices are considered. One of the FACTS device at the distribution side called Interline Dynamic Voltage Restorer (IDVR) is proposed to mitigate the voltage sag/swell. The building blocks of IDVR used for injecting the voltage can either be voltage source inverter (VSI) or current source inverter (CSI). In this paper, IDVR with two CSI as its building blocks is considered to mitigate voltage sag/swell. PV source is used at the DC link of IDVR to provide the necessary energy to mitigate sag/swell. The simulations are performed in MATLAB environment.