A Cubic Boost DC-DC Converter with Reduced Switch Voltage Stress for DC Microgrid Application

Switched-inductor and switched-capacitor based converters can achieve a substantially higher step-up gain compared to the classical boost converter; however, in many topologies their practicality is constrained by excessive voltage stress on semiconductor devices, often approaching the full output voltage. To address these limitations, this paper proposes a cubic boost-derived DC-DC converter that extends the quadratic concept to achieve a cubic boost-voltage with reduced voltage-stress (CBRV) across all switches and capacitors. The proposed CBRV topology ensures continuous input current and maintains a common ground between input and output, making it highly suitable for renewable energy and DC microgrid applications. Comprehensive steady-state analysis is performed under both continuous and discontinuous conduction modes (CCM and DCM), including non-idealities. A small-signal model is developed to examine dynamic performance. Comparative evaluation with existing high-gain converters demonstrates superior gain-stress trade-off and efficiency. A 500 W laboratory prototype validates the design, achieving a conversion from 36 V to 650 V and confirming the practicality and robustness of the CBRV topology in steady state and dynamic operations. Finally, simulation studies are conducted for the CBRV converter in a DC microgrid application.