STATCOM based controller for a three phase system feeding single phase loads

Majority of loads connected in the power system are single phase loads. Large concentration of single phase non-linear loads will inject harmonics in to the system and create unbalance in the source current. Most of these loads consume more reactive power and thus increases feeder losses and reduces active power flow capability of the system. In this paper, 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. A simulation model of the system is developed in MATLAB SIMULINK and tested with linear and non-linear loads under balanced and unbalanced conditions.