Partial Discharge Diagnostic of Medium Voltage Switchgear under

Partial Discharge Diagnostic of Medium Voltage Switchgear under Operating Conditions using a special PD- Probe Diagnostica ´ 07 Prof. Dr. -Ing. habil. Rainer Haller Power & Environmental Engineering ZCU Pilsen/ Cz

Quality Control Stages of MV GIS and PD - Measurement demands development assembling high sensitivity ( ~ p. C) Ø failure identification Ø failure location pd m ea su re m en t manufacturing Ø transport/ on site assembling operation pd data base (pc- based system) PRPD pattern Diagnostica ´ 07 Prof. Dr. -Ing. habil. Rainer Haller Power & Environmental Engineering ZCU Pilsen/ Cz

Phase- Resolved-PD- (PRPD) Pattern measured parameter: q (U, φ, t, …. ) acc. to CIGRE- format) Diagnostica ´ 07 Prof. Dr. -Ing. habil. Rainer Haller Power & Environmental Engineering ZCU Pilsen/ Cz

PRPD- Pattern of a defect part PD pattern of a separation between the insert and the cast resin at the grounded side of a 36 -k. V-spacer Diagnostica ´ 07 Prof. Dr. -Ing. habil. Rainer Haller Power & Environmental Engineering ZCU Pilsen/ Cz

special problems for on- site- diagnosis § demand for no- switching- off of operational voltage, but compatibility to pd- test procedures during manufacturing process measuring of PRPD- pattern for comparison with reference pd- data- base seems to be necessary calibrating procedures are necessary (unconventional measuring methods like acoustical/ optical methods are not sufficient) coupling elements are necessary Diagnostica ´ 07 Prof. Dr. -Ing. habil. Rainer Haller Power & Environmental Engineering ZCU Pilsen/ Cz

Typical measurement conditions for on- site- testing pd´s superimposed with large disturbances caused by near located SFC Diagnostica ´ 07 pd- spectra with disturbances Prof. Dr. -Ing. habil. Rainer Haller Power & Environmental Engineering ZCU Pilsen/ Cz

special problems for on- site- diagnosis § requirement of high measuring sensitivity special requirements/ procedures for suppressing of noise/ disturbances Diagnostica ´ 07 Prof. Dr. -Ing. habil. Rainer Haller Power & Environmental Engineering ZCU Pilsen/ Cz

pd- on- site measurement by electromagnetic field coupling Diagnostica ´ 07 Prof. Dr. -Ing. habil. Rainer Haller Power & Environmental Engineering ZCU Pilsen/ Cz

transfer characteristic of pd- probes (UHF - measurement) UHF- Measurement [acc. to IEC 60270] Diagnostica ´ 07 Prof. Dr. -Ing. habil. Rainer Haller Power & Environmental Engineering ZCU Pilsen/ Cz

transfer characteristic with and without pdprobe Diagnostica ´ 07 Prof. Dr. -Ing. habil. Rainer Haller Power & Environmental Engineering ZCU Pilsen/ Cz

diagnostic- object: medium voltage switchgear capacitive sensor user- table h. v. joints 36 k. V GISsubstation modules Diagnostica ´ 07 Prof. Dr. -Ing. habil. Rainer Haller Power & Environmental Engineering ZCU Pilsen/ Cz

measuring sensitivity with capacitive sensor coupling equivalent test circuit q- sensitivity is non sufficient Diagnostica ´ 07 Prof. Dr. -Ing. habil. Rainer Haller Power & Environmental Engineering ZCU Pilsen/ Cz

medium voltage switchgear with additional cable- parts capacitive sensor user- table h. v. joints cableparts Diagnostica ´ 07 Prof. Dr. -Ing. habil. Rainer Haller Power & Environmental Engineering ZCU Pilsen/ Cz

transfer characteristic with additional cable- parts test circuit transfer characteristic Diagnostica ´ 07 Prof. Dr. -Ing. habil. Rainer Haller Power & Environmental Engineering ZCU Pilsen/ Cz

pd calibration with and without connected power cable with power cable -classical pd- meas. system -- pd- probe without power cable Diagnostica ´ 07 Prof. Dr. -Ing. habil. Rainer Haller Power & Environmental Engineering ZCU Pilsen/ Cz

diagnosis results capacitive sensor pd probe and measuring impedance defect spacer Diagnostica ´ 07 Prof. Dr. -Ing. habil. Rainer Haller Power & Environmental Engineering ZCU Pilsen/ Cz

conclusions Ø pd measurements are up to now an essential tool for quality testing of electrical insulation even for on- site diagnosis Ø demanding for no- switching- off of operation voltage during the testing leads to non classical measurement methods (UHF- measurement by special pd- probes) Diagnostica ´ 07 Prof. Dr. -Ing. habil. Rainer Haller Power & Environmental Engineering ZCU Pilsen/ Cz

Ø if into the switchgear a capacitive sensor is available, so by using a special pd- probe sensitive PD- on site- tests can be provided Ø the measuring sensitivity can be increased significantly by using of appropriate resonance elements like cabel- parts Ø this testing arrangement can be used in principle even for similar configurations. Diagnostica ´ 07 Prof. Dr. -Ing. habil. Rainer Haller Power & Environmental Engineering ZCU Pilsen/ Cz

Thank you -dekuji za pozornost Questions ? Answers ! Diagnostica ´ 07 Prof. Dr. -Ing. habil. Rainer Haller Power & Environmental Engineering ZCU Pilsen/ Cz