IEEE 400.4:2015 pdf free download – IEEE Guide for Field Testing of Shielded Power Cable Systems Rated 5 kV and Above with DampedAlternating Current (DAC) Voltage
1.2 Scope
This guide presents the practices and procedures for testing and diagnosis of shielded power cable systemsrated 5 kV and above using DAC voltages. It applies to all types of power cable systems that are intendedfor the transmission or distribution of electric power.The tabulated test levels assume that the cablesystems have an effectively grounded ncutral system or a grounded metallic shicld.
1.3 Purpose
The purpose of this guide is to provide uniform practices and procedures for performing (DAC) voltageoff-line tests on installed shielded power cable systems in the field and to provide guidelines for evaluationof the test results. As at present certain test parameters and procedures require further study andclarification,this guide provides a starting point that can be grown and improved with time as moreexperience is gathered from the field and analyzed.
DAC excitation: Complete process of stressing the power cable under test with Part 1, continuouslyincreasing test voltage up to selected maximum test voltage level, and Part 2, a damped-(co)sinusoidaloscillation with circuit natural frequency and a given damping factor.
DAC voltage PD test: A field test in which the focus of the test is to obtain information about the presenceand behavior of partial discharge (PD) in the cable section under the test.
DAC voltage withstand test procedure: Is the whole procedure of DAC voltage step phase (byperforming DAC excitations with increasing voltage level) followed by a DAC voltage hold phaseconsisting of series of DAC voltage excitations as applied consecutively at selected voltage levels to thepower cable under test.
damped alternating voltage DAC: Starting from a (negative or positive)maximum voltage level andhaving damped sinusoidal oscillations around the zero level. It is characterized by the peak value,V c , thecircuit natural frequency，f , , and the damping factor，D,.
damping factor, D, percentage: Equals the voltage difference between the first and second peak of samepolarity divided by the voltage value of the first peak.
electrical tree: Tree-like growths, consisting of non-solid or carbonized micro-channels that can occur atstress enhancements such as protrusions,contaminants，voids or water tree/dry insulation interfacessubjected to electrical stress for extended time periods. At the site of an electrical tree, the insulation isdamaged irreversibly.If the voltage stress on the electrical tree is above the inception voltage，partialdischarge will be present, the tree will grow, and a failure can occur in only a matter of time.
hybrid cable system: A cable system consisting of cables with very different dielectric or constructioncharacteristics,for example, extruded dielectric insulation cable and laminated insulation cable or cableswith filled and unfilled insulations.
(insulation) weak spot: A part of the cable insulation system where, due to one or more factors such asmechanical, chemical, or thermal stresses, the insulation medium breaks down before the rest of the systemunder certain applied voltage.An insulation weak spot that leads to a breakdown at operating voltage issometimes called a gross defect.
laminated dielectrics: Insulation formed in layers typically from fluid-impregnated tapes of eithercellulose paper or polypropylene or a combination of the two.Examples include paper-insulated, lead-covered (PILC) cable designs,mass-impregnated, non-draining (MIND) cable designs, high pressure pipetype cable designs, and self-contained cable systems.
partial discharge (PD): Localized clectrical discharge that only partially bridges the insulation betweenconductors.
partial discharge (PD) pulse: A high-frequency current pulse that results from a PD. In a shielded powercable, the pulse propagates away from the PD source in both directions along the cable.