Interleaved Buck-Boost N-Phase High-Efficiency Converter with Soft Switching and Low Output Voltage Ripple

In this paper, an interleaved buck-boost n-phase converter with the soft-switching operation is proposed. All the switches are switched at zero voltage by applying an inductor between every two consecutive phases. These inductors cause the soft-switching operation through all switches of the converter by discharging the inherent voltage of switches' capacitor and keeping the voltage of switch at zero until the switching period ends. Also, due to the existence of these inductors, the output diodes are disconnected during zero current. The large number of phases in this kind of converter reduces the output voltage ripple, output and input current ripple and increases the reliability of the converter. Increasing the number of phases of the converter reduces the current stress on the power switches and, thereby, leads to reducing conduction losses of the power switches. This kind of converter has a high efficiency due to its soft-switching operation of switches and reduction of the conduction losses of all switches. Finally, the experimental results of a four-phase prototype of this converter with 100 W output power for input voltage 20 V and output voltage 100 V are presented for determining the features of the desired converter.