Self-balanced single-inductor single-input multiple-output bipolar DC-DC converter based on SEPIC-Cuk combination with no cross-regulation

This work proposes an improved DC-DC converter having modular multiport configuration for bipolar outputs using single switch. This converter has capability to be scaled for n bipolar or 2n unipolar outputs. It uses only one DC source and single switch to achieve the above-mentioned modularity, and each bipolar level employs a combination of SEPIC and Cuk converter. This helps in generating one bipolar or two unipolar outputs, having opposite polarity at every port. The modularity of this converter depends on the switch rating. The proposed converter can have n outputs depending on the voltage and current rating of switch used. Key advantages of the proposed converter are (1) reduced component count, (2) Self-balancing of output side capacitor voltage levels, (3) no cross-regulation and (4) low ripple in input and output current both. It makes this converter suitable for low voltage application. To improve the system response during dynamic load change, control scheme has been designed. Stability analysis for the control system has been presented. The proposed converter is validated experimentally up to 2 kW load rating to analyse the feasibility of the proposed modular configuration.