Abstract: Inverters designed using reduced active semiconductor devices can be of interest to the industry because of their lower cost and enhanced reliability linked to their less complex gating and control circuitries. In this paper a four switch three phase b-4 topology for the grid connected application in an effort to reduce the cost of the inverter is investigated. Admittedly, this topology warrants higher voltage ratings of the semiconductor devices used and the dc-link split capacitors used with respect to a conventional six-switch three-phase b-6 topology inverter for a specific set of grid voltages. In this paper, application of four power semiconductor switch based three phase inverter has been proposed for renewable energy based generalized three phase micro grid interconnection. The b-4 of three phase inverter topology is investigated to make the commercial micro grid system to be cost effective and hardware optimized. A simple sinusoidal pulse width modulation (SPWM) is used to control the switching of the four switches. Main advantage of this converter is that it needs only four switches. As a result the system is less costly and also the complexity in associated with gating and control circuitry is very much reduced
Keywords: Four switch inverter, Sinusoidal pulse width modulation, Micro grid. VSI.