Determination of Dielectric Models Based on Effective Multi-Exponential Fittings
In high-voltage (HV) transmission and distribution systems, HV apparatuses are subjected to electrical, thermal, and mechanical stresses that deteriorate the insulation performance. The polarization and depolarization current (PDC) measurement is an effective tool used for evaluating insulation perf...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-06-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/16/12/4615 |
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| author | Jedsada Raxsa Phethai Nimsanong Thanatorn Mai-Eiam Peerawut Yutthagowith |
| author_facet | Jedsada Raxsa Phethai Nimsanong Thanatorn Mai-Eiam Peerawut Yutthagowith |
| author_sort | Jedsada Raxsa |
| collection | DOAJ |
| description | In high-voltage (HV) transmission and distribution systems, HV apparatuses are subjected to electrical, thermal, and mechanical stresses that deteriorate the insulation performance. The polarization and depolarization current (PDC) measurement is an effective tool used for evaluating insulation performances. The depolarization current represented by the summation of the discharge currents with the different time constants can be utilized for the development of the dielectric model based on the extended Debye’s model (EDM). This paper presents effective techniques for determining the dielectric model. Iterative approaches with predetermination of the time constants and least squares methods (either linear ordinary or percentage ones) were utilized to fit the depolarization current in the form of multi-exponential functions. The fitting parameters determined by the proposed method with the linear ordinary least squares (OLLS) method and provided by commercial software agree very well only in the high current and beginning range. Application of the linear percentage least squares (PLLS) method shows better accuracy than that of the OLLS method, and the deviation from the measured one in the low current range and the late measuring time were reduced significantly. The fitted current by this proposed technique with the PLLS method agrees well with the measured current throughout the whole recording time, even in the low current and late time range. From the accurately fitted currents, the dielectric model and the dielectric loss factors can be determined precisely, and the insulation condition of HV equipment can be evaluated properly. |
| first_indexed | 2024-03-11T02:32:03Z |
| format | Article |
| id | doaj.art-be7b903a95f049a697c77293e6144cab |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-11T02:32:03Z |
| publishDate | 2023-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-be7b903a95f049a697c77293e6144cab2023-11-18T10:11:48ZengMDPI AGEnergies1996-10732023-06-011612461510.3390/en16124615Determination of Dielectric Models Based on Effective Multi-Exponential FittingsJedsada Raxsa0Phethai Nimsanong1Thanatorn Mai-Eiam2Peerawut Yutthagowith3Department of Electrical Engineering, School of Engineering, King Mongkut’s Institute of Technology Ladkrabang, Bangkok 10520, ThailandMetropolitan Electricity Authority, Bangkok 10110, ThailandDepartment of Electrical Engineering, School of Engineering, King Mongkut’s Institute of Technology Ladkrabang, Bangkok 10520, ThailandDepartment of Electrical Engineering, School of Engineering, King Mongkut’s Institute of Technology Ladkrabang, Bangkok 10520, ThailandIn high-voltage (HV) transmission and distribution systems, HV apparatuses are subjected to electrical, thermal, and mechanical stresses that deteriorate the insulation performance. The polarization and depolarization current (PDC) measurement is an effective tool used for evaluating insulation performances. The depolarization current represented by the summation of the discharge currents with the different time constants can be utilized for the development of the dielectric model based on the extended Debye’s model (EDM). This paper presents effective techniques for determining the dielectric model. Iterative approaches with predetermination of the time constants and least squares methods (either linear ordinary or percentage ones) were utilized to fit the depolarization current in the form of multi-exponential functions. The fitting parameters determined by the proposed method with the linear ordinary least squares (OLLS) method and provided by commercial software agree very well only in the high current and beginning range. Application of the linear percentage least squares (PLLS) method shows better accuracy than that of the OLLS method, and the deviation from the measured one in the low current range and the late measuring time were reduced significantly. The fitted current by this proposed technique with the PLLS method agrees well with the measured current throughout the whole recording time, even in the low current and late time range. From the accurately fitted currents, the dielectric model and the dielectric loss factors can be determined precisely, and the insulation condition of HV equipment can be evaluated properly.https://www.mdpi.com/1996-1073/16/12/4615dielectric loss factorextended Debye’s modelmulti-exponential function fitPDC measurementpercentage least squares method |
| spellingShingle | Jedsada Raxsa Phethai Nimsanong Thanatorn Mai-Eiam Peerawut Yutthagowith Determination of Dielectric Models Based on Effective Multi-Exponential Fittings Energies dielectric loss factor extended Debye’s model multi-exponential function fit PDC measurement percentage least squares method |
| title | Determination of Dielectric Models Based on Effective Multi-Exponential Fittings |
| title_full | Determination of Dielectric Models Based on Effective Multi-Exponential Fittings |
| title_fullStr | Determination of Dielectric Models Based on Effective Multi-Exponential Fittings |
| title_full_unstemmed | Determination of Dielectric Models Based on Effective Multi-Exponential Fittings |
| title_short | Determination of Dielectric Models Based on Effective Multi-Exponential Fittings |
| title_sort | determination of dielectric models based on effective multi exponential fittings |
| topic | dielectric loss factor extended Debye’s model multi-exponential function fit PDC measurement percentage least squares method |
| url | https://www.mdpi.com/1996-1073/16/12/4615 |
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