Novel cascaded H-bridge sub-multilevel inverter with reduced switches towards low total harmonic distortion for photovoltaic application

ABSTRACTThe main objective of this paper is to develop a novel inverter to produce multilevel output voltage. This paper proposes the cascaded H-bridge with sub-multilevel inverter (CHBSMLI) using three unequal DC sources in order to get 15-level output voltage. The unequal DC sources can be obtained from photovoltaic cell. The proposed CHBSMLI reduces the number of switches which in turn reduces the switching losses. The multicarrier sine Pulse Width Modulation (PWM) technique is proposed to obtain pure sinusoidal signal with reduced total harmonic distortion (THD). The performance analysis of the proposed three-phase CHBSMLI carried out using MATLAB/simulink with minimised THD and switching loss. The gating signals are generated using a Spartan-3E FPGA processor. The single-phase 15-level CHBSMLI with PWM developed to validate the simulation result.