| 摘要 |
PROBLEM TO BE SOLVED: To improve the power failure of a PWM converter device mounted on an AC railway vehicle. SOLUTION: A power failure detector 20 is constituted of a multiplier 12, an absolute value circuit 22, and a comparator 23, and this calculates the instantaneous value of the input voltage of a PWM converter 6 with a multiplier 21, obtains the absolute value value of this instantaneous value from the absolute value circuit 22, this operates the comparator 23 when the obtained absolute value exceeds the threshold V1 , and outputs a power failure detection signal by making the comparator operate, whereby even if power failure occurs in an AC power source 1 when it is regenerating the power form load 10 on the side of the AC power source 1, this effect is surely detected by this detector. |
