A simplified converter with simultaneous multi-level AC and boost DC outputs for hybrid microgrid applications

In hybrid microgrids, integration of multiple renewable energy sources to AC and DC buses of grid require a boost and multi-level inverters. Depending on the requirement, these boost and multi-level converters are connected either in parallel or in cascaded. In this parallel or cascaded arrangement the device count and control complexity increases. And, also it requires a separate AC and DC output control (for modulation index and duty ratio). So, these arrangement cannot give the fully controlled simultaneous DC and AC outputs. With this intent, this paper proposes a simplified converter with simultaneous AC and DC outputs. This proposed converter topology is derived by modifying the DC-DC boost converter power switch with a multi-level inverter. This resulting simplified topology requires less number of devices (switches) to produces a simultaneous boost DC and multi-level AC waveforms with a shoot through protection for a multi-level converter. A suitable pulse width modulation (PWM) control strategy is described and simulation results are presented using MATLAB/Simulink. And also, the mathematical analysis of the proposed converter has been derived and compared with conventional/already existing designs.