Multiphase Multilevel Modular DC–DC Converter for High-Current High-Gain TEG Application

This paper presents a high-efficiency zero-current-switching (ZCS) switched-capacitor (SC) dc-dc converter for high-current high-voltage-gain TEG application. Compared with the traditional hard switching SC circuits, the proposed circuit achieves ZCS for all the switches, thus minimizing the switching loss and electromagnetic interference noise. The huge electrolytic capacitor bank existing in the hard switching SC circuit, which is used to reduce the voltage ripple and achieve high efficiency, is eliminated. The low-capacitance ceramic capacitor is utilized instead. Different from other ZCS SC circuits that insert a magnetic core, the proposed circuit utilizes stray inductance that is present in the circuit to achieve ZCS, thus leading to small-size, low-cost, and high-reliability features. The proposed circuit also owns continuous input current and low-output-voltage ripple features. Therefore, the power loss related to the input capacitor can be minimized. By using the proposed topology, high-efficiency and high-power-density SC dc-dc converters could be made for high-current and high-voltage-gain application. Simulation and experimental results are given to demonstrate the validity and features of the proposed topology.