Analysis of harmonic mitigations using hybrid passive filters

With the recent development in the power electronic devices, the use of power electronics in controlled Variable Speed Drives (VSD) is increasing in industrial and domestic applications. These controlled VSDs provide many advantages and flexibility in those applications, but at same time cause harmonic distortion in the power system. In recent years, significant attention has been focused on line side harmonics because they overload power network infrastructure, affect quality of the grid, cause reliability problem in equipment and waste energy. Therefore mitigations of harmonics have been considered as important research issues in power system. A growing number of different harmonic mitigation techniques are available using active and passive components. In various industrial applications, passive harmonic mitigation techniques are used in low power drives due to the cost and size point of view. In this paper, a comparative analysis has been performed for various configurations of passive components and finally a hybrid passive filter has been optimized for the harmonic mitigation. In some applications such as micro-grid or standalone grid, there are strict requirements for Total Harmonic Distortion (THD) of voltage at the Point of Common Coupling (PCC). Therefore, a new harmonic factor (K_{i_new}) has been defined to calculate the THD_V based on current harmonics.