ACTIVE SAFETY CIRCUIT OF SWICHING DEVICES FOR SUPPLING POWER

摘要

PURPOSE: An active protection circuit of a switching device for power supply is provided to reduce operation costs of an electric railroad vehicle by guaranteeing a reliability enhancement about a power conversion device or a stable train service. CONSTITUTION: A power unit(110) supplies power by connecting an active protection circuit of an IGBT device(130) to both ends of high voltage DC power in series. A first diode(120) is connected from the + side of the power unit to the collector side of the IGBT device and proceeds with a normal direction current. A second diode(140) is connected from the emitting side of the IGBT device to the collector side of the IGBT device and prevents a current flow which is from the collector side to the emitting side if the IGBT device is turned off by a gate drive. A Zener diode(160) is connected to the - side of a third diode(150), is connected to a resistance for a voltage generation, and is connected in series according to a predetermined rated voltage. A resistor(170) is connected to the - side of the Zener diode and supplies a voltage by being connected with the gate drive of the IGBT device.