This work deals with the power quality improvement of fourteen bus systems with and without STATCOM using multi level inverter VSI circuit. The VSI is extremely fast in response to reactive power change. Multilevel inverters with a large number of steps (more than 50 levels) can generate high quality voltage waveforms, good enough to be considered as suitable voltage template generators. This paper is focused on minimizing the number of power supplies and semiconductors for a given number of levels. An active harmonic elimination method is applied to determine the firing angles for each level to eliminate any number of specific higher order harmonics of multilevel converters with unequal dc voltages. A Static Compensator (STATCOM) is a device that can provide reactive support to a bus. It consists of voltage source inverters connected to an energy storage device on one side and to the power system on the other. STATCOM is a device which can supply the required reactive power at low values of bus voltage and can also absorb active power if it has large energy storage. It also required having less harmonic contents in the output and higher compensation VA capacity. When the reactive power of the load is changing continuously, a suitable fast response compensator is needed. STATCOM, TCTC, UPFC, TCSC, SVC are the compensators belonging to FACTS devices. Models for the STATCOM is developed using MATLAB simulink. The simulation of the STATCOM is performed in the Simulink environment and the results are presented.

Keywords: Reactive power, STATCOM, VSI, MATLAB