Comparison and performance evaluation of renewable to grid integration schemes: Single-phase high-frequency fuel cells and PV inverters applications

This paper compares and evaluates two current-controlled interfacing schemes for integrating renewable energy sources to a single-phase utility/grid using multi-stage high-frequency (HF) transformer isolated power conditioning system. Operation, merits and demerits are discussed for each scheme with operating waveforms. Several features e.g., utility line power factor, line current THD, size of power electronics system, ease of connection to utility line and simplicity of control, risk of transformer saturation, losses and components ratings in power electronics system, high power density design, and most significantly the size and cost of electrolytic capacitor are compared. Based on their competitive and comparative beneficial features, characteristics of energy source(s), and given specifications, a suitable scheme is justified.