Photovoltaic micro-inverter with front-end DC-DC converter and half-wave cycloconverter

A photovoltaic micro-inverter with a half-bridge inverter, half-wave cycloconverter and front-end boost converter is proposed with a series resonant circuit. A PV panel is connected to the micro-inverter via the front-end DC-DC converter. The micro-inverter is integrated to the grid by using the half-wave cycloconverter. The Half-wave cycloconverter and the half-bridge inverter are interfaced by using the series resonant tank. The series resonant tank is used to obtain soft switching at turn-on of the half-bridge and the half-wave cycloconverter switches. The front-end DC-DC converter is controlled by using pulse width modulation and it is used to track the maximum power point of the PV panel. Phase shift power modulation is used to obtain grid synchronized 50Hz current. The proposed micro-inverter is analyzed to obtain an expression for average output power over one switching cycle and to identify possible control variables. The micro-inverter is simulated by using the MATLAB/Simulink and PLECS toolboxes. Soft switching behavior of the power switches is analyzed by using the obtained switching wave-forms from the simulation.