harmonic distortion Improvement and power factor increasing by modifying the hybrid filter structure by using fuzzy multi-objective meta-heuristic algorithms

Harmonics in power systems produce unsuitable effects such as saturation of iron cores of transformers and electrical machines, improper operation of protection relays and increase in losses, so they should be reduced. Moreover , a low power factor leads to occupying the capacity of lines with reactive power, which leads to additional costs in the system. This issue causes the regional power companies to consider penalties for subscribers who have a low power factor. Reducing THD and increasing power factor are two important goals in improving power quality. A capacitor can be used to compensate the power factor, as there is a possibility of resonance occurring in this situation. In order to achieve the mentioned targets, a hybrid power filter is proposed, which consists of a passive filter and an active filter. The active filter includes three parts: identification, modulation and inverter. To reduce the power rating of the active filter inverter, a passive filter is used with it. The elements of the passive filter should be determined in such a way that both the THD and power factor is optimized, so this work should be done with a multi-objective meta-heuristic algorithm, which SPEA-II algorithm is used in this manuscript. At the end, the efficiency of the proposed hybrid filter will be illustrated by simulation in MATLAB software.