| 摘要 |
The insulation monitor is intended to protect diesel-electrical locomotive against ground faults. It functions in two ways. Basic scheme is represented by bridge circuit formed from positive and negative generator terminals (Rp, Rm) and two separate resistors (Ra, Rb). In the mid-branch of the bridge is a high resistance potentiometer (Rs). The voltage drop created on the part of the potentiometer by the mid-branch current is introduced into a circuit of an absolute value, and the output of which controls signaling and earth-fault relays.The bridge is supplied by the locomotive generator (G) and by galvanic isolated internal generator (IG) which is a part of locomotive battery voltage converter. The performance of the insulation monitor is improved by making use of high resistance potentiometer in the mid-branch instead of relay and internal generator for total insulation resistance measurement.
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