A Voltage-Quadrupler Interleaved Bidirectional DC-DC Converter With Intrinsic Equal Current Sharing Characteristic for Electric Vehicles

A voltage-quadrupler interleaved bidirectional dc-dc converter with intrinsic equal current sharing is presented in this article. The proposed converter offers a wide voltage conversion ratio, which makes it suitable for interconnecting the energy storage unit with dc bus for electric vehicle applications. A high voltage gain and low voltage stress across switches are achieved by adopting the capacitive voltage-divider stage, which enables the designer to employ a low-voltage switch with a small ON-resistance R-DS(ON). As a result, it allows the converter to run more efficiently and cooler. An interleaved connection at the low-voltage side paves the way for reducing the current ripple, which reduces the filter size and increases the power-density. Moreover, a built-in equal current sharing is achieved for two interleaved phases without using a current-sharing control scheme. The operating principle, steady-state characteristics including the current and voltage stress of the switches, and comparison with other state-of-the-art bidirectional converters are carried out in detail. Finally, to verify theoretical analysis, a 2-kW scaleddown laboratory prototype of the proposed converter using Gallium-Nitride switches is implemented.

Automated summary

The article introduces a voltage-quadrupler interleaved bidirectional dc-dc converter with intrinsic equal current sharing, suitable for electric vehicle applications. By adopting capacitive voltage-divider stage, it achieves high voltage gain and low voltage stress across switches, resulting in more efficient and cooler operation.