A direct AC-AC converter for electronic power transformer based on energy injection control

This paper presents a direct AC-AC converter for an electronic power transformer based on the energy injection control. It achieves single-stage energy transformation. A simple and special direct AC-AC converter is used instead of a matrix converter with a complex control method and many switches. This paper analyzes its work models and operation principle in energy injection mode and free oscillation mode. A simulation is carried out to prove that the direct AC-AC converter work in soft switch state all the time, and the output current is unchanged when the load is changing. The simulation also verifies that this special electronic power transformer can achieve power single transformation and energy bidirectional flow, which is beneficial to improve energy utilization efficiency.