| 摘要 |
PURPOSE:To enable a detection of high reliability without a contact required, by means of transmitting an impedance of the supervised circuit at rotor side to that at stator side with a rotary transformer. CONSTITUTION:An earth insulating resistance RX at one pole of main circuit 22 of rotary unit 21 in the rotary machine is connected to a rotary transformer 23 that makes a transmission to an impedance bridge 24. At secondary side of the rotary transfomer 23, for instance, is connected a condenser C1 in parallel and a condenser C2 in series. To the impedance bridge 24 is connected the rotary transformer 23 as one arm, and a resistor R0, R1, r0 and reactance L0 as another arm, and an operation is to be made with a current fed from an AC power source 25. If lowering down an insulating resistance with the main circuit 22 of the rotary unit 21 grounded, the earth insulating resistance RX is reduced causing an unbalance of the conversion impednce bridge to the primary side of the rotary transformer 23, with a current flowing in a detecting resistor RL, thus with this detection made to detect the earth insulation being lowered. In such way, with a contact like brushes not required, an anomalousness detection of high reliability can be operated. |
