| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a three-level power conversion device that prevents a switching element from being brought into an overvoltage state, even if the operation of a gate block becomes unstable. <P>SOLUTION: The three-level power conversion device is constituted of a switching leg formed of a series connecting body which is formed of first, second, third, and fourth switching elements, a gate logic 1 which applies prohibition gate processing to a reference gate signal in order to feed gate signals to the switching elements, and an addition protector 2 which adds a protection operation to an output of the gate logic 1. The addition protector 2 includes a first latch unit 21, AND circuits 22A, 22B, 22C and 22D, a voltage lowering detector 23, a clock loss detector 24, a second latch unit 26 which holds the operation state of the voltage lowering detector 23 or the clock loss detector, and a first timer unit 27. An output of the second latch unit 26 is set as a trigger condition of the first latch unit 21, and the signal is inverted and imparted to an input of the other of the AND circuits 22A, 22D. <P>COPYRIGHT: (C)2011,JPO&INPIT |
