| 摘要 |
PURPOSE:To enable commutation failure to be detected with simplicity by providing a DC transformer in series with a section resistance of a chopper control circuit equipped with a power supplementing device. CONSTITUTION:A DC transformer DCCT2 is provided in series with a section resistance R0 in a chopper control circuit which is equipped with a power supplementing circuit SUP. Because of this machanism, in case if commutation failure should occur, electric current passes through a main thyrister TH1 bypassing the section resistance R0. In this case, the current which is to pass in accordance with chopper's cycle of TH1 does not pass through DCCT2, and therefore, it is possible to determine the commutation failure at the time when the electric current period in the output of DCCT2 disappears. |
