부산대학교 도서관

It is difficult to design the backward converter when energy harvesting current transformer (CT) works within a wide range of the primary voltage. It reduces the range of the secondary of CT by variable turns ratio technology within a wide range of the primary voltage. Thus, variable turns ratio technology enhances the practicability and flexibility of CT. After sampling and analyzing the secondary of CT, the secondary turns can be adjusted automatically by controlling the AC switches which are connected with the secondary winding. MOSFETs are used to construct the AC switch. It reduces the cost and control difficulty by optimizing the AC structure and drive circuit. The scheme can be applied to other types of transformers with automatic turns ratio.