Fuzzy controlled Three Phase STATCOM for compensation of Single Phase Loads

Abstract

The unbalanced currents caused by single-phase loads that are connected across any two terminals of the three-phase by using STATCOM will compensate the system. Most of these loads consume more reactive power and thus increases feeder losses and reduces active power flow capability of the system..  In this concept, a STATCOM based controller for a three phase system feeding single phase loads is presented. The objectives of the controller in the system is to compensate the inductive loads to obtain nearly unity power factor, balance the source currents by cancelling the effect of unbalanced loads and to filter out the load harmonic currents in order to form a sinusoidal supply current. Single phase synchronous reference frame theory based algorithm is used for generating the reference source currents. The dc-link voltage of STATCOM has been regulated to a reference value under various load conditions. This can be done for single phase linear and non-linear loads under balanced and unbalanced conditions. From the waveforms obtained it is clear that the source current and source voltage are in phase that is, source side power factor is unity. Also it is found that the source currents are become balanced and sinusoidal under the application of the controller. In this PI controller is replaced with fuzzy logic controller to improve the performance of the system. The harmonic content in the source current is reduced by using Fuzzy controller.