Power Quality Improvement Using Multilevel Inverter Based Dynamic Voltage Restorer with PI Controller

With the invasion of power electronic based devices in all sectors in the recent past, not only in industry but also in domestic, the quality of power is degraded considerably and need to be addressed as the power quality has direct economic impact. Out of several power quality issues, voltage sag and swells in the medium and low voltage distribution grids are considered in this paper, as their occurrence is more frequent in the grids and it is necessary to protect sensitive loads against such disturbances. Among a variety of solutions proposed to handle this issue, Dynamic Voltage Restorer (DVR) is considered to be the most efficient and effective solution and hence, a twenty seven levels cascaded multilevel inverter based DVR is proposed in this paper to compensate the voltage under balanced voltage sags in a distribution system. Simulations are carried out using MATLAB/ SIMULINK to estimate the performance of the proposed method and the results show considerable improvement in the power quality terms of harmonics.