IEEE 1732:2017 pdf free download – IEEE Recommended Practice for Space Charge Measurements on High-Voltage Direct-Current Extruded cablesfor Rated Voltages up to 550 kV
3.1 Definitions
For the purposes of this document, the following terms and definitions apply.The IEEE Standards DictionaryOnline should be consulted for terms not defined in this clause.2
cable loop: See : test loop.
cable system:Cables with installed accessories.Cable accessories are typically joints and terminations. Theremay be other types of accessories associated with a cable system (e.g., measuring devices or fixtures).Theseneed only to be incorporated in the test objects to the extent that they are deemed to have an impact on theoperational characteristics of the cable system (adapted from CIGRE Technical Brochure [TB] 496:2012,page 6,1.5.1).
compensation cable: Cable that serves for compensating the polarization and conduction currents of themeasured cable subjected to space charge measurements with the thermal step method and has identicalcapacitance to the measured cable ( for more details, see Annex B).
compensation cable loop: Compensation cable arranged in a cable loop with two terminations.
depolarization time: Time starting—after voltage removal—as soon as the cable conductor has been short-circuited and grounded.
full-size cables: Cables of the same size, design, and rated voltage as the power cables installed in the field.
load cycle test: Part of the electrical type tests for dc extruded cable systems for power transmission at a ratedvoltage up to 550 kV(adapted from CIGRE TB 496:2012, page 19,4.4.2).(Equivalent to the heating cyclevoltage test after IEC 62067:2011,12.2.4, for ac cables.)
long-duration voltage test: Part of the prequalification test for dc extruded cable systems for powertransmission at a rated voltage up to 550 kV(adapted from CIGRETB496:2012, page 14,3.4).(Equivalent tothe heating cycle voltage test after IEC 62067:2011,13.2.4, for ac cables.)
measured cable: Cable subjected to space charge measurements with the thermal step method where thethermal diffuser is installed (for more details, see Annex B).
measured cable loop: Measured cable arranged in a cable loop with two terminations (for more details,seeAnnex B).
negative voltage depolarization time: Depolarization time following the application of a voltage of negativepolarity between the cable conductor and the grounded cable metal sheath.
negative voltage poling time: Poling time in case that the polarity of the voltage applied between the cableconductor and the grounded cable metal sheath is negative.
poling time: Time starting as soon as the voltage applied between the cable conductor and the grounded cablemetal sheath reaches the rated voltage U, of the tested cable system—-as defined in CIGRETB496:2012,page8,1.5.3.
positive voltage depolarization time: Depolarization time following the application of a voltage of positivepolarity between the grounded cable conductor and the cable metal sheath.
5.1 Introduction
Given the importance to space charge formation of cross-linking byproducts associated with the crosslinkingagent dicumyl peroxide, and of anti-oxidants and molecular voltage stabilizers, and the effect of humidity(water) and the relatively rapid transmission of water through extruded insulation (in particular polyethyleneand ethylene-propylene rubber), considerable care shall be exercised in performing PEA or TSM spacecharge measurements on HVDC extruded cables. Exposure to humid environments shall be minimized andlimited strictly to the measurement duration.Constant and predefined values of cable conductor temperature,temperature gradient across insulation wall, and humidity of the surrounding environment shall be maintainedduring such measurements, to every extent possible.Ambient conditions during PEA or TSM measurementsshall be recorded and included in the space charge measurement report.