Implementation of Power Factor Controller using STATCOM

Abstract

With the advancement of technology, the demand for electrical energy has also increased. The demand of electricity has become the parameter of development of a nation. An electrical utility company has to use its existing transmission capacity to feed it ever increasing demand for electricity, due to that the transmission lines has to be operated near its thermal stability limits. Operating the transmission lines near or above thermal stability limits makes system vulnerable to faults, moreover, it also increases the losses in the system. One way to increase the transmission capacity of the system without operating it to its thermal stability level is to provide reactive power compensation at various locations so that its power factor is maintained. Reactive power compensation improves the voltage profile of the system, increases the power transfer in the lines and reduces losses.A Flexible AC Transmission System (FACTS)is an AC transmission system incorporating power electronic based or other static controller which provides better power ow control and enhanced dynamic stability by control of one or more ac transmission system parameters (voltage, phase angle and impedance).STATCOM (Static compensator) can be a series, a shunt, or a combination of both devices which is generally used to solve power quality problems in distribution systems and also used in correcting power factor, maintaining constant distribution voltage and mitigating harmonics in a distribution network. However, majority applications are done with a Shunt Compensation because of the simplicity of implementation. STATCOM is mostly a Voltage Source Converter (VSC) based shunt device generally used in distribution system to improve power quality. The main advantage of STATCOM is that, it has a very sophisticated power electronics based control which can efficiently regulate the current injection into the distribution feeder or bus. The other advantages are: Canceling the effect of poor load power factor, Suppressing the effect of harmonic content in load currents, Regulate the voltage of distribution bus against sag/swell etc. compensation the reactive power requirement of the load.