A New Multiport DC-DC Converter for DC Microgrid Applications

In this paper, a new multiport DC-DC converter is proposed for DC microgrid applications. Besides, the proposed configuration has several benefits for the design and operation of DC microgrids such as reducing multiple power conversions, reducing number of elements and voltage boosting capability. The bidirectional buck-boost structure of the proposed topology allows for enhanced flexibility to connect sources and loads with different voltage and power levels. The control strategy is developed to achieve power control for renewable sources such as MPPT for PV, in addition to a certain degree of resilience for DC sources availability while maintaining boosted DC link voltage. The key feature of the proposed configuration is that it offers full control over DC link voltage regardless of resource availability. A detailed steady state analysis is conducted to derive the voltage relations between all ports. Additionally, the state-space averaging followed by small-signal modelling and frequency response-based controller design for the proposed topology is discussed. A MATLAB/Simulink-based simulation study is conducted to demonstrate the performance of the proposed multiport converter topology under different operating conditions. Finally, the performance of the proposed multiport converter is validated through an experimental study.