Design of Single-Switch Multi-Port DC–DC Converter for Electric Vehicle Applications

DC–DC converters play a very important role in Electric Vehicle (EV) usage. In the conventional EV systems, the charging of both low-voltage and high-voltage batteries requires the exploitation of separate DC–DC converters, which results in more output voltage ripple, increased on-off and device losses, and reduced overall system performance. In general, multi-port converters require more switching devices and energy storage components, thus making them more complex and costly. To get around these drawbacks, this study proposes a new Multi-Port DC–DC Converter-based EV charging arrangement. The proposed topology, here termed the Single Switch Single Input Double Output Converter (SSSIDOC), integrates a Buck–Boost Converter (IBBC). Under this architecture, the boost converter steps up the voltage, while the auxiliary output is generated from the buck converter, tracking the input voltage. The benefits of the designed IBBC include minimized load voltage ripple, improved converter transfer gain, enhanced effectiveness with reduced on–off and device losses, fewer passive components, and compact design compared to the multiport topologies reported so far. The small-signal model of the IBBC is derived and Proportional Integral (PI) controller parameters are designed with the Ziegler–Nichols tuning scheme. The performance of the converter is tested with different load environments, like purely resistive load and battery load, by using MATLAB/Simulink simulations and hardware prototype implementation. Results show that IBBC with Equivalent Series Resistance (ESR) of inductors and capacitors achieves an efficiency of 88.9–98.6% (experimental) and 89.67–99.97% (simulation) with a small output voltage ripple. Moreover, the converter provides variable output voltage levels depending on variations in the duty cycle, which proves its efficacy and applicability for the conversion of Electric Vehicle power.