Isolated Three-Phase AC to DC Converter with Matrix Converter Applying Compensation for Voltage Error by Voltage-based Commutation

This paper proposes a compensation method for a voltage error by a voltage-based commutation of an isolated AC-DC converter using the matrix converter with a discontinuous current mode (DCM) and a continuous current mode (CCM) for rapid battery charger applications. The isolated AC-DC converter with the matrix converter is expected to be more compact because a medium-frequency AC inductor which is connected to the medium-frequency transformer is used instead of a boost inductor. However, the small medium-frequency inductor causes the input current distortion. In addition, the transmission power error occurs due to the voltage error by the commutation. In this paper, the voltage error caused by the voltage-based commutation is analyzed based on the relationship between the current direction and the three-phase voltage in the initial step of the voltage-based commutation. The two voltage compensations method by the two-level compensation and the linear approximation are combined. As a result, the input current THD was reduced by 70 % at the boost ratio 1.0.