POWER CONVERSION DEVICE

摘要

PROBLEM TO BE SOLVED: To transfer power while maintaining soft switching between a three-phase AC voltage source and a DC voltage source.SOLUTION: A power conversion device 10 comprises: a three-phase AC voltage source 80; three power conversion parts 30; and a DC voltage source 6. The power conversion part 30 includes phase bridges 1-4. The phase bridges 1 and 2 connected in parallel and the phase bridges 3 and 4 connected in parallel are connected via a load. In the phase bridge 1, positive electrode terminals are connected to phases of the three-phase AC voltage source 80, and negative electrode terminals are short-circuited with each other. In the phase bridge 4, positive electrode terminals and negative electrode terminals are short-circuited with each other. The DC voltage source 6 is connected in parallel with any one phase bridge 4. The phase bridges 1 and 2 are switched in such a manner that a primary voltage repeats a voltage of the three-phase AC voltage source 80 and an inversion voltage for a phase periodγvia a zero voltage for each half term. The phase bridges 3 and 4 are switched in such a manner that a secondary voltage repeats a voltage of the DC voltage source 6 and an inversion voltage for the phase periodγvia a zero voltage for each half term in the same frequency as the primary voltage and while delaying a phase by (180°-control angleδ).