Research on the Dead-Time Control Scheme for the Four-Switch Buck-Boost Converter

This research work is based on the unified quadrilateral inductor current modulation method of the four-switch buck-boost (FSBB) converter, which can achieve the zero-voltage-switching (ZVS) turn-on for all the switches. However, the duration of the dead-time between the complementary pulses for the two switches in a branch needs to be carefully controlled when considering the parasitic parameters of the switch, especially in high switching frequency application field. Without the constraint boundary of the dead-time, FSBB may loss soft-switching characteristics and the active switch is transferred into the hard-switching situation. In this paper, the dead-time constraint for ZVS is analyzed under both Buck mode and Boost mode situations for the FSBB converter. The theoretical conclusions are verified by the simulation results.