Improved asynchronous voltage regulation strategy of non-inverting Buck-Boost converter for renewable energy integration

A systematic control strategy for Non-inverting Buck-Boost converter based on equivalent duty ratio is presented in this paper. Extend-Buck mode and Extend-Boost mode are first derived as transition mode for least inductor current in constant frequency operation and are modified with consideration of parasitic elements. Equivalent duty cycle is introduced to switch among different working modes and to regulate output voltage during each mode. Gain-scheduling based controller is employed considering mode switching nonlinearity. Special benefits offered by this method are decreased inductor current and losses, continuous voltage conversion ratio and easy-implemented constant frequency operation without input voltage measurement.