Pulse Train Controlled PCCM Buck-Boost Converter

摘要

In order to reduce the impact of the decrease of inductor current during the freewheel switch on the pulse of next cycle, this paper puts forward a novel control scheme of pulse train (PT) according to the working character of the pseudo continuous conduction mode (PCCM) Buck-Boost converter. The novel scheme contains two pseudo continuous variables and makes the controller produce different current-controlled pulses depending on different-energy voltage-controlled pulses. The working process of the PCCM Buck-Boost converter under this new control scheme is analyzed in detail and the ratio of high-energy and low-energy voltage-controlled pulses is present. Compared with traditional control scheme with one pseudo continuous variable, the performance of the new converter is improved significantly. Simulation and experimental results verify the feasibility of the new control scheme and the correctness of the theoretical analysis.