To provide a capacitor bank for DC filter used for the DC power source of a power converter which can make a system to be operated continuously, even when a failure occurs in a capacitor by only disconnecting the capacitor from a power source circuit by using the failure detecting signal of the capacitor without stopping the entire system.
An expulsion fuse 4 composed of a fusible piece 12 and a spring 13 which pulls the piece 12 is connected in series with a capacitor 11, and a commutation circuit 2 composed of a commutation capacitor 21, a charging power source, and an inductance 24 is connected to both ends of the piece 12, and then a semiconductor switch element or switch 15 which is conducted by the failure detecting signal of the capacitor 21 is connected in series between the piece 12 and circuit 2, so that when a failure occurs in the capacitor 11, only the capacitor 11 can be disconnected from the power source by fusing the piece 12 by making a large oscillating current to flow to the piece 12 by means of the failure detecting signal of the capacitor 21 and, at the same time, separating the piece 12 by means of the spring 13.
NISHIGUCHI NOBORU
MORITA KOJI
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