Patent•
Method for testing withstand voltage of rubber and plastic insulated power cable
04 Nov 1998-
TL;DR: In this article, the relation between the lightning impulse breakdown voltage and the test waveform breakdown voltage is determined from the relationship between the water tree deterioration state and the Lightning Impulse breakdown voltage.
Abstract: PROBLEM TO BE SOLVED: To screen a cable having a water tree causing a trouble upon intrusion of a lightning impulse voltage by determining the relation between the lightning impulse breakdown voltage and the test waveform breakdown voltage and then applying a test waveform breakdown voltage to a cable to be tested. SOLUTION: Relation between the lightning impulse breakdown voltage and the test waveform breakdown voltage is determined from the relation between the water tree deterioration state and the lightning impulse breakdown voltage and the relation between the water tree deterioration state and the test waveform breakdown voltage. Screening of water tree is then performed by applying a specified test waveform voltage to a cable to be tested. More specifically, a cable having a water tree causing a trouble upon intrusion of a lightning impulse voltage can be screened by applying a test waveform voltage other than a lightning impulse in place of a lightning impulse voltage which is difficult to be applied over the entire line. Since this method is also applicable to a long cable, reliability of an actual line can be ensured.
Citations
More filters
Patent•
24 Dec 2014
TL;DR: In this article, a method for testing impulse withstand voltages of ultra-high-voltage converter transformers on the basis of scale models is presented, which includes simulation research according to particular structures of the scale models, and determining test waveforms; arranging lead-out taps on the scale model according to research requirements to acquire the required test waveform, and allowing relevant faults to be set.
Abstract: The invention discloses a method for testing impulse withstand voltages of ultrahigh-voltage converter transformers on the basis of scale models. The method includes performing simulation research according to particular structures of the scale models designed on the basis of a scaling theory to acquire distribution parameters of windings of the scale models, and determining test waveforms; arranging lead-out taps on the scale models according to research requirements to acquire the required test waveforms, and allowing relevant faults to be set; manufacturing actual equipment, testing the actual equipment by the aid of the scale models, and adjusting parameters of the manufactured power equipment to obtain the required test waveforms; simplifying the structure of the equipment and a test process, acquiring voltage distribution waveforms of the windings, and allowing taps to be arranged so as to set corresponding faults to perform test research; acquiring voltage distribution characteristics of the windings with impulse voltages under normal conditions and fault conditions by means of analysis and research, and acquiring voltage distribution characteristics of the original ultrahigh-voltage converter transformers by the aid of scaling relations. The method has the advantages that test steps can be simplified, the test cost can be lowered, test periods can be shortened, and the voltage distribution characteristics of the windings under the different fault conditions can be researched.
2 citations
Patent•
15 Jan 2019
TL;DR: In this paper, a method for evaluating the lightning current ablation ability of a grounding wire in a transmission line is proposed. But the method is limited to the case of single-strand grounding wires.
Abstract: The invention discloses a method for evaluating the lightning current ablation ability of a grounding wire in a transmission line. The method comprises: by testing the relationship between the cross-section size of different wires, the diameter of a single strand of a wire, the magnitude of a lightning current, the type of a lightning current waveform, and the residual breaking force, respectively, and the lightning current ablation ability of a grounding wire in a transmission line , obtaining quantitative evaluation data of 5 aspects, comprehensively evaluating the lightning current ablationability of the grounding wire in the transmission line , and providing technical support for the lightning-proof selection of the grounding wire in the transmission line, therefore ensuring the safeand stable operation of the power grid.