Experimental verification of a one-turn transformer power supply circuit for gate drive unit

This paper proposes a power supply circuit for gate drive units (GDU) that uses a one-turn transformer which is given advantages in term of cost and loss. The structure of this one-turn transformer consists of one turn in the primary winding and multiple turns in the secondary winding. Then the circuit is connected in series to a main switching device to obtain a power for the GDUs. The proposed circuit can be applied to all kinds of main circuit topologies such as a multilevel converter topology or a matrix converter in addition to a conventional 6-arm inverter. In this paper, the design method of the one-turn transformer and the characteristics are described accordingly based on the fundamental experimental results. Besides, the proposed circuit with GDUs is tested in a three-phase inverter for verification purpose. The results confirmed that the proposed gate drive circuit is working without an external power source circuit when the output current is 1/10 times over the rated current of the switching device.