Modulation and Control of Single-Stage Bidirectional Isolated Direct-Matrix-based AC-DC Converters

In this paper, a single-stage bidirectional isolated direct-matrix-based AC-DC converter with a power factor correction is proposed. This AC-DC converter can control not only the DC output voltage or current, but also the AC grid current with a single conversion stage, which helps to achieve a higher power density with a lower complexity. A modulation scheme that can achieve a zero voltage switching (ZVS) or zero current switching (ZCS) operation in all switches is developed. Hence, the switching frequency of the converter can be increased higher, leading to the smaller passive components. The proportional-resonant (PR) controller is utilized to achieve the unity power factor and low total harmonic distortion (THD) current. The proposed topology has been verified by simulation results for a 3.3 kW system.