| 摘要 |
PROBLEM TO BE SOLVED: To solve the following problem: In a conventional power converter circuit for high voltage, a circuit system that insulates and transmits a gate driving signal to a semiconductor switching element using an optical fiber cable from a control circuit requires an electric-optical converter circuit or an optical-electric converter circuit, which causes high cost.SOLUTION: As an insulator for a gate driving signal applied to an electric power conversion system for high voltage, only an insulation transformer and an inexpensive photocoupler are used without use of an optical fiber cable. A signal insulation circuit with the insulation transformer is connected in series to a signal insulation circuit with the photocoupler. A series connection point is connected with an intermediate potential point between a reference potential and an emitter potential of a semiconductor switching element that executes driving through the series insulation circuit. |
