Analysis on Stator Current Characteristics in Synchronous Generators Under Dynamic Rotor Interturn Short Circuit Fault
Yuan Xing-hua,
Qiu Ming-hao,
Jiang Meng-ya,
He Yu-ling,
Wan Shu-ting,
Tang Gui-Ji
Issue:
Volume 8, Issue 1, June 2022
Pages:
1-8
Received:
4 June 2022
Accepted:
24 June 2022
Published:
5 July 2022
DOI:
10.11648/j.ijecec.20220801.11
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Views:
Abstract: Rotor interturn short circuit (RISC) is a common electrical fault in synchronous generators. By far, scholars have carried out a lot of researches on static rotor interturn short circuit (SRISC), while dynamic rotor interturn short circuit (DRISC) is rarely taken into account. This paper analyzes the stator current characteristics before and after DRISC fault in synchronous generators. First, the expressions of the air-gap flux density respectively in normal, SRISC, and DRISC cases, are derived. Then the two-dimensional finite element model is established to analyze the stator current under the aforementioned three conditions. Finally, experiments are carried out on the CS-5 prototype generator to test the stator currents. The experimental results are consistent with the theoretical analysis and the finite element calculation data. It is shown that the occurrence of the dynamic rotor interturn short circuit will reduce the root mean square value as well as the odd harmonics of the magnetic flux density and the stator current, while at the meantime it will increase the new generated even harmonics. Compared with the static short circuit, the current curve of the stator phase shows an obvious "peak". With the aggravation of the short circuit degree between dynamic turns, the effective value of current and the odd harmonics will be decreased. The stator current in the dynamic rotor interturn short circuit cases is generally between those of normal condition and static rotor interturn short circuit case.
Abstract: Rotor interturn short circuit (RISC) is a common electrical fault in synchronous generators. By far, scholars have carried out a lot of researches on static rotor interturn short circuit (SRISC), while dynamic rotor interturn short circuit (DRISC) is rarely taken into account. This paper analyzes the stator current characteristics before and after ...
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Development of Expert Finding and Opinion from the Field of Electrical Sciences
Nenad Popovic,
Sasho Gelev
Issue:
Volume 8, Issue 1, June 2022
Pages:
9-14
Received:
1 July 2022
Accepted:
8 August 2022
Published:
16 September 2022
DOI:
10.11648/j.ijecec.20220801.12
Downloads:
Views:
Abstract: Electricity theft is a criminal act, which is treated differently in different countries. Starting from the premise that everyone is innocent until proven guilty, it is necessary to give every accused an equal chance for a fair and impartial trial. Considering that it is a professional issue, specifically an electrotechnical area for which the court does not have adequate knowledge, there is a need to hire experts for the purpose of a fair and democratic judicial process. Hiring skilled persons (specifically in the field of electrical engineering) allows the court to work in a relaxed manner without delving into the technical areas itself. In the course of the previous practice in the preparation of expert reports made by fellow experts, differences can be observed, sometimes diametrically, not only in the production methodology, but also in the form of the approach to the problem. This can cause confusion for users of these findings. On the other hand, expertise must be done impartially and professionally, leaving no doubt of bias towards any party. The purpose of this paper is to contribute to the methodology for producing a professional and objective finding and opinion, especially since so far no papers have been produced for such a thing, at least not here in the Republic of North Macedonia. Also, a methodology is offered for the calculation of damage caused by this theft, towards a distribution system operator.
Abstract: Electricity theft is a criminal act, which is treated differently in different countries. Starting from the premise that everyone is innocent until proven guilty, it is necessary to give every accused an equal chance for a fair and impartial trial. Considering that it is a professional issue, specifically an electrotechnical area for which the cour...
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