Soft-Switching Modulation Strategy of High-Frequency Dual Active Bridge Converter Based on Triple Phase-Shifting Control

Abstract

Dual active bridge (DAB) converters are widely used in work scenarios that require energy efficient bidirectional flow. In order to reduce the on-state loss of the converter while reducing the switching loss to improve the transmission efficiency of the converter, this paper analyzes the waveforms of the DAB converter in different modes, and derive the constraint conditions to ensure the zero voltage switching (ZVS) of the low-voltage side under different working modes. On this basis, combined with the optimal control algorithm of inductor current stress, a quasi-optimal low-voltage side ZVS modulation strategy of inductor current stress is proposed. This strategy improves the working conditions of the device in the full power range, further eliminates the switching loss under the premise of reducing the conduction loss, and greatly improves the efficiency. The efficiency improvement is particularly obvious in the low power section, which is beneficial to further improve the switching of the converter’s Frequency and power density. Finally, an experimental platform is built for verification, and the experimental results verify the effectiveness of the proposed modulation strategy.