The Field Test of High Voltage Cable Impedance Parameters

The cables in 66 kV and 220 kV systems are used in single-phase style, and it must be grounded between the cables. The connection ways between different lengths of cables are in different ways, thus, it may occur influence to circuit parameters, especially to zero sequence impedance. In order to clarify the situation from theory analysis to calculate impedance under all kinds of connection modes, the paper gives an actual cable measured value, and introduces the correct measuring method, together, points out the matters needing attention in the measurement.

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An Analysis of On-Bord High-Voltage Converters of Single-Phase Alternating Current with Increased Miroelectric Power Factor

Elektrichestvo ◽

10.24160/0013-5380-2020-10-44-51 ◽

2020 ◽

Vol 10 (10) ◽

pp. 44-51

Author(s):

Yury Yu. SKOROKHOD ◽

◽

Sehgey I. VOL’SKIY ◽

Keyword(s):

High Voltage ◽

Single Phase ◽

Input Current ◽

Voltage Converter ◽

Input Unit ◽

Power Circuit ◽

Electrical Systems ◽

Static Converters ◽

Technical Requirements

The power circuit arrangements of on-board high-voltage static converters fed from a 3000 V AC single-phase network that in the general case produce multi-channel AC and DC output voltages are considered. The basic technical requirements posed to such converters are formulated. The general structural diagram of high-voltage converters with improved electric power consumption quality is given. Possible power circuit arrangements for the high-voltage converter input unit based on single-phase input current correction devices are considered. A classification and criteria for comparative evaluation of the possible power circuit arrangements of these devices are proposed. The information presented in the article will be of interest for specialists engaged in designing on-board electrical systems involving high-voltage converters that must comply with strict requirements for the quality of consumed single-phase input current.

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Study on Selective Leakage Protection System of Mine High Voltage Grid Based on Harmonic Phase Comparison

The Open Electrical & Electronic Engineering Journal ◽

10.2174/1874129001509010253 ◽

2015 ◽

Vol 9 (1) ◽

pp. 253-262

Author(s):

Liu Zhongfu ◽

Zhang Junxing ◽

Shi Lixin ◽

Yang Yaning

Keyword(s):

High Voltage ◽

Power Supply ◽

Power Supply System ◽

Supply System ◽

Neutral Point ◽

Arc Suppression Coil ◽

Zero Sequence ◽

Harmonic Extraction ◽

Power Direction ◽

The Stability

As for the wide application of arc suppression coil to the grounding in neutral point of mine high voltage grid, grid leakage fault rules and harmonic characteristics of the neutral point grounding system through arc suppression coil are analyzed, the selective leakage protection program “zero-sequence voltage starts, fifth harmonics of grid zerosequence voltage and zero-sequence current are extracted for phase comparison” is proposed, and corresponding fifth harmonic extraction circuit and power direction discrimination circuit are designed. The experimental results show that the protective principle applies not only to the neutral point insulated power supply system, but also to the power supply system in which neutral point passes arc suppression coil, which can solve selective leakage protection problems under different neutral grounding ways, improving the reliability of selective leakage and guaranteeing the stability of the action value.

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A novel fault section locating method based on distance matching degree in distribution network

Protection and Control of Modern Power Systems ◽

10.1186/s41601-021-00194-y ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Zhenxing Li ◽

Jialing Wan ◽

Pengfei Wang ◽

Hanli Weng ◽

Zhenhua Li

Keyword(s):

Single Phase ◽

Distribution Network ◽

Matlab Simulink ◽

Grounding Resistance ◽

Blind Zone ◽

System Transition ◽

Transition Resistance ◽

Zero Sequence ◽

Matching Degree ◽

Amplitude Characteristics

AbstractFault section location of a single-phase grounding fault is affected by the neutral grounding mode of the system, transition resistance, and the blind zone. A fault section locating method based on an amplitude feature and an intelligent distance algorithm is proposed to eliminate the influence of the above factors. By analyzing and comparing the amplitude characteristics of the zero-sequence current transient components at both ends of the healthy section and the faulty section, a distance algorithm with strong abnormal data immune capability is introduced in this paper. The matching degree of the amplitude characteristics at both ends of the feeder section are used as the criterion and by comparing with the set threshold, the faulty section is effectively determined. Finally, simulations using Matlab/Simulink and PSCAD/EMTDC show that the proposed section locating method can locate the faulty section accurately, and is not affected by grounding mode, grounding resistance, or the blind zone.

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