Synchronous multi-channel PD measurements

The synchronous, multi-channel PD measurements provide a new potential in location, identification and separation of multiple PD sources and their discrimination from external noise in variety of HV assets. The independent PD observers, like coupling capacitors, bushing taps, capacitive or inductive sensors made the multi-channel PD evaluation feasible on HV motors, generators, three phase transformers or single-line cable systems with cross-bonding links. Three different multi-channel PD evaluation techniques are proposed: 3-phase amplitude relation diagram (3PARD), 3-phase time relation diagram (3PTRD) and 3-channel frequency relation diagram (3CFRD). The successful application of all techniques is presented.