Analytical modelling of modulation of soft-switched partial-resonant link inverter suitable for PV

Soft-Switched, Partial-resonant link, buck-boost, current source inverters [1], feature indirect energy transfer which enables power decoupling between the input and the output side of the converter. Soft switching is applied to all switches, reducing switching losses and stress of the switches. However, to successfully generate symmetrical three-phase output currents, a special modulation technique, which is a combination of pulse-width and pulse-amplitude modulation, needs to be engaged. Analytical model of this modulation method is given. Thorough analysis is performed, and analytical equations for modulation are derived. To validate the proposed analytical model, simulations are performed in MATLAB-Simulink. The obtained results were satisfactory. An experimental, proof-of-principle prototype is constructed to supplement theoretical analysis and simulations.