H-bridge buck-boost converter with dual feedforward control

This paper presents a new control method for H-bridge buck-boost converter regulated by single voltage feedback and dual feedforward controls. This converter has two pairs of the switch, one acts as a synchronous buck and another as a synchronous boost operations, and therefore is suited for battery powered applications to provide an output voltage that is below or above the input voltage. In order to realize good transient performance not only with high conversion efficiency but also with seamless circuitry transitions between the buck and buck-boost regions of operation, it is proposed that the voltage feedback is only applied to the buck section and the input voltage and the road current feedforward signals are applied to the boost section. As a result, excellent transient performances for the step load change are obtained without spoiling the efficiency for wide range of the input voltage.