A Novel Nonisolated Dual-Input High Step-Up DC-DC Converter With Three-Winding Coupled Inductor for Electric Vehicle Charging Station

Dual-input DC-DC converters are increasingly recognized as integrated systems for various applications, such as electric vehicle charging station and distributed energy systems, due to the compact size and cost-effectiveness. Therefore, a novel dual-input single-output high step-up DC-DC converter with three-winding coupled inductor (DISO-TWCI), which secondary and tertiary windings are integrated with switched capacitor, is proposed to achieve a high voltage conversion ratio without an extremely duty cycle. And the diode-capacitor clamp circuit is utilized to minimize the voltage spikes across switches, which is beneficial for selecting switches with low voltage ratings. Moreover, the switches can achieve the Zero Current Switching (ZCS) with the help of leakage inductor from TWCI. By integrating the passive clamp network, the number of components in DISO-TWCI can be reduced, significantly enhancing its performance. The operating principles, steady-state analysis, design and performance analysis of DISO-TWCI are described in detail. Finally, the theoretical correctness is verified by building an experimental prototype with switching frequency of 100 kHz. The rated power is 400 W with 24-24V input and 400V output.