Cascaded Buck-Boost Derived Interlink Multi-port Converter for simultaneous operation of isolated and non-isolated Loads in a DC Nanogrid

The primary objective of the Multi-Port Converter (MPC) is to offer a single-stage power conversion that integrates energy sources and loads in the most efficient manner while minimizing the power density and cost. The majority of MPCs are developed with just one design feature in focus, which allows them to deliver either isolated or non-isolated loads. In this paper, a SIMO-based Cascaded Buck-Boost Derived Interlink Multi-port Converter (CBBDIMC) is proposed. The proposed converter includes two conventional buck-boost converters connected in cascade with common supply and ground to realize two output ports for non-isolated loads. Additionally, the complementary characteristics of the switches are utilized efficiently in order to get voltage at an additional isolated port. By using high-frequency transformers and bridge-rectifiers, high-frequency alternating voltage available at this port can be converted into dc. Moreover, the complementary action of the cascaded boost converters leads to a reduction in the magnitude of ripples present in the source current. The various modes of operation is discussed in the paper. The performance validation of CBBDIMC is done using simulation in MATLAB followed by its experimental results captured on a laboratory prototype.