| 摘要 |
PURPOSE:To prevent two power sources to be connected in parallel by supplying an off control signal to a to the first high-speed semiconductor switch at detection of an overcurrent, and supplying an on control signal to the second high-speed semiconductor after passage of the time of the difference between the off time of the first high-speed semiconductor switch and the on time of the second high-speed semiconductor switch from that time. CONSTITUTION:When it detects an overcurrent at time t1, it supplies an off signal to the first high-speed semiconductor switch 5c. Next, at the time t2 when the time Td of the difference between the off time of the switch 5c and on time of a switch 6c has passed, an on signal is supplied to the switch 6c. Next, at t3, the turning-off of the first semiconductor conductor switch 5c completes, and at time t4 immediately after it, the turning-off of the second high-speed semiconductor switch 6c completes. And by the large short-circuit current flowing from a second power source through the switch 6c, an electromagnetic contactor operates and performs shut-off. Hereby, uninterruptive power unit and short-circuit load are quickly separated, and other sound loads are not affected at all. |
