Single-Phase Differential Buck–Boost Inverter With Pulse Energy Modulation and Power Decoupling Control

This paper presents a single-phase differential buck-boost inverter that possesses both buck-boost and active power decoupling functions without adding any power electronics or increasing the complexity of driver circuits, as compared with the previous differential inverters. Two types of operating principles are introduced: the unipolar operation with new pulse energy modulation technique enabling the inverter to operate under both discontinuous conduction mode and continuous conduction mode, and the bipolar operation with energy-based active power decoupling delivering the second-order ripple power into the output film capacitors, thus eliminating the large electrolytic capacitor at the dc side. Small-signal modeling analysis is conducted to show the characteristics of the proposed system and control. Simulation and experimental results verified the feasibility of operating principles for the differential buck-boost inverter and successful power decoupling with substantial reduction of second-order component in the dc current.