Enhanced Single-Inductor Single-Input Dual-Output DC-DC Converter With Voltage Balancing Capability

Single-inductor single-input dual-output (SI-SIDO) dc-dc converters with a higher power density and fewer components are attractive for various applications such as renewable energies, portable chargers, PFC, HVdc, LED lightening, and electric vehicles (EVs). However, the voltage balancing of the output capacitors is a big challenge and always limits the application of these converters. In this regard, an enhanced SI-SIDO three-level dc-dc converter with a high voltage gain, inherited common ground condition, and voltage balancing capability is proposed in this article. A time-multiplexed control scheme is designed for the proposed converter to charge two output capacitors independently and provide different voltage levels for different requirements. Hence, the proposed converter can provide balanced or nonbalanced output voltages for various applications, maintaining constant output voltages even under unbalanced loads. Furthermore, it can be designed to support bidirectional operation. Because of the voltage balancing feature, the proposed converter can provide the dc-link voltage balancing for different applications, such as the bipolar low-voltage dc distribution system and the neutral-point-clamped inverter. The performance of the proposed topology is verified by the PLECS simulation program and experimentally in an 800-W prototype.