Enhancing Power Transfer Capacity of Transmission System by a Reduced Magnetics Based 48-Pulse STATCOM Controller

The static synchronous compensator (STATCOM) being the state-of-the-art voltage source converter (VSC) based dynamic shunt compensator in FACTS family (Flexible Alternating Current Transmission System) is increasingly employed in transmission system for reactive power control, increase of power transfer capacity, voltage regulation etc. Utilization of such controller at the middle location of the high voltage transmission system is focused in this paper to enhance the power transmission capacity of the line. A forty-eight pulse STATCOM evolved on two level gate turn-off thyristor based voltage source converters (GTO-VSCs) topology to be operated at fundamental frequency switching modulation is employed to have higher voltage gain in the mid point of the transmission line enabling to achieve reasonable power gain in the system. Its magnetics is evolved with single stage magnetics that require only four transformers with its cumulative rating (MVA) equal to that of the controller itself and thus, leads to considerable saving in cost. Employing this STATCOM to be operated under voltage control mode, at mid-section of an EHVAC line, power system network is simulated using MATLAB platform. The simulation results show that the STATCOM is effective to reasonably increase the 132kV line loading.