| 摘要 |
PURPOSE:To perform surely monitoring of abnormality of a shaft voltage and to enhance the reliability of an electric rotary machine by a method wherein a voltage between two points of a rotor shaft, a voltage between the rotor shaft and the earth, and a field voltage are detected, and the voltage value and the frequency value of the shaft voltage are compared. CONSTITUTION:The earth brushes 7 are connected to the two points of the rotor shaft 4, and the voltage between both the earth brushes is detected with a voltage detector 8. A resistor 10 is inserted between the earth brush 7b on one side and the earth, and the voltage is detected with a voltage detector 11. Moreover a voltage detector 9 is connected between field brushes 6 to detect the field voltage. Detected signals of the respective voltage detectors 8, 9, 11 are inputted into a voltage comparing circuit 13 and a frequency comparing circuit 12 to be compared, and when an abnormality is generated, output is send out from an abnormality detecting circuit 14 to perform monitoring of the shaft voltage. |
