A new switching scheme for fuel cell supported reduced switch three-phase multilevel inverter topology

This paper proposes a new switching technique for fuel cell supported twenty one levels three-phase multilevel inverter topology having less number of power electronics components. This topology of the inverter is realized with asymmetrical configuration. The purpose of going for more number of voltage levels is to obtain less distortion and DC component in the output voltages. A combination of unipolar Pulse Width Modulation (PWM) and comparison of sinusoidal modulating wave with DC component at fundamental frequency has been implemented for switching of power electronics devices. A Fuel-Cell generation systems is used as a source for this three-phase inverter for interfacing it to the grid. It is observed that the integrated inverter with grid satisfies all the grid requirements such as phase angle, frequency and amplitude of grid voltage. In addition to this the Total Harmonic Distortion (THD) of the output voltages of the inverter are within the specified limits of IEEE 519 standard. Matlab/Simulink environment is used for the modeling and switching of three-phase multi-level inverter.