Patent ID: 11959975
Assignee: BENDER GMBH & CO. KG
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A method for selectively determining a partial insulation resistance Rx of an outgoing line (4) in a branched ungrounded power supply system (2) which is monitored using an insulation monitoring device (10) which actively superposes a square pulse measuring voltage Uq on the ungrounded power supply system (2), the method comprising the following steps:
calculating partial insulation resistance Rx according to Rx=Ue/Ixstat with a stationary conductor-to-ground voltage Ue dropping via the outgoing line (4) and a stationary partial current Ixstat measured in the outgoing line (4) in a settled state,
wherein
Ue=Iges*Rfges applies to stationary conductor-to-ground voltage Ue with a total insulation resistance Rfges transmitted by the insulation monitoring device (10) and a total measuring current Iges driven by known square pulse measuring voltage Uq, wherein total measuring current Iges is calculated from Iges=Uq/(Rfges+Ri) with a known inner resistance Ri of the insulation monitoring device (10), meaning partial insulation resistance Rx is calculated from Rx=(Rfges*Uq)/((Rfges+Ri)*Ixstat).