EMI Noise Reduction Design of DC-DC Converter Based on ZVS for EV

The reliability of high-voltage power converters, which play a key role in driving electric vehicles, is becoming increasingly important owing to the rapid popularization of electric vehicles. In particular, the DC-DC converter, which plays the most basic role among the components of the power conversion system of an electric vehicle, uses a high-voltage battery as a source to properly control and provide the voltage specifications required by each electronic device, which significantly affects the electrical efficiency and performance of the vehicle. In this electrical interaction process, reliability problems such as electromagnetic waves between electronic devices and driver safety problems are crucial owing to the use of large batteries. High-voltage DC-DC converters applied to electric vehicles can be designed using various topologies. The LLC resonant topology, which can be implemented with ZVS and ZCS to minimize electrical losses in high-speed switching environments, is often used. Therefore, this study analyzes the characteristics of electromagnetic EMI-conducted emission noise under the ZVS switching operation conditions of LLC converters and presents critical factors related to the optimal design of noise reduction.