Ruppert-Schmidt, Maren Greta (2025)
Sensitivity Calculation Based on the Adjoint Variable Method for the Transient Nonlinear Electroquasistatic-Thermal HVDC Cable Joint Problem.
Technische Universität Darmstadt
doi: 10.26083/tuprints-00028949
Dissertation, Erstveröffentlichung, Verlagsversion
Kurzbeschreibung (Abstract)
Germany's transition to green energy requires new transmission infrastructure, including underground High-Voltage Direct Current (HVDC) technology. HVDC cable joints, which interconnect cable segments, are the most vulnerable part of these systems due to installation errors and electric field stresses. Since the length of individual cable segments is limited to 1.5-2 km due to transportation constraints, a large number of cable joints is required. As a result, the reliability of these joints is critical to the overall performance of the system. This dissertation contributes to enhancing the reliability of HVDC cable joints by developing simulation tools aimed at facilitating future advancements in joint design and reliability assessment.
The dissertation begins with a discussion on electrothermal modeling of HVDC cable joints during steady-state and transient operations. A freely available electrothermal solver is implemented, specifically tailored for HVDC cable joint simulation. The solver addresses challenges such as field- and temperature-dependent material properties and the multi-rate nature of the transient electrothermal problem. It is validated against commercial software using a 320 kV HVDC cable joint specimen, with brief analyses conducted for both steady-state and transient operations.
The dissertation focuses on developing simulation tools for efficient sensitivity computation, which are vital for design and optimization. Two complementary methods for sensitivity computation are implemented: the direct sensitivity method, which scales with the number of investigated design parameters, and the adjoint variable method, which scales with the number of investigated quantities of interest but is independent of the number of design parameters. The derivation of the adjoint variable method for transient electroquasistatic-thermal problems represents a core contribution of this thesis.
The dissertation also demonstrates how simulation can estimate model parameters from experimental data using an inverse problem approach, highlighting the role of measurement data quality. It discusses factors such as measurement sensitivity, data points, and noise corruption.
Finally, the dissertation provides a comprehensive literature review on modeling and simulation approaches for slow polarization processes in HVDC cable joints. This chapter reviews various methodologies from the literature, aiming to enhance the accuracy of simulations and analyses for HVDC insulation systems exposed to prolonged unidirectional electric fields.
By providing tools for simulation-aided design, this dissertation aims to enable more effective and reliable approaches to HVDC cable joint development. In doing so, it supports the broader goal of improving energy transmission infrastructure and contributing to a stable and sustainable energy supply.
| Typ des Eintrags: | Dissertation | ||||
|---|---|---|---|---|---|
| Erschienen: | 2025 | ||||
| Autor(en): | Ruppert-Schmidt, Maren Greta | ||||
| Art des Eintrags: | Erstveröffentlichung | ||||
| Titel: | Sensitivity Calculation Based on the Adjoint Variable Method for the Transient Nonlinear Electroquasistatic-Thermal HVDC Cable Joint Problem | ||||
| Sprache: | Englisch | ||||
| Referenten: | Späck-Leigsnering, Dr.-Ing. Yvonne ; Koch, Prof. Dr. Myriam ; De Gersem, Prof. Dr. Herbert | ||||
| Publikationsjahr: | 10 Januar 2025 | ||||
| Ort: | Darmstadt | ||||
| Kollation: | xix, 82 Seiten | ||||
| Datum der mündlichen Prüfung: | 20 November 2024 | ||||
| DOI: | 10.26083/tuprints-00028949 | ||||
| URL / URN: | https://tuprints.ulb.tu-darmstadt.de/28949 | ||||
| Kurzbeschreibung (Abstract): | Germany's transition to green energy requires new transmission infrastructure, including underground High-Voltage Direct Current (HVDC) technology. HVDC cable joints, which interconnect cable segments, are the most vulnerable part of these systems due to installation errors and electric field stresses. Since the length of individual cable segments is limited to 1.5-2 km due to transportation constraints, a large number of cable joints is required. As a result, the reliability of these joints is critical to the overall performance of the system. This dissertation contributes to enhancing the reliability of HVDC cable joints by developing simulation tools aimed at facilitating future advancements in joint design and reliability assessment. The dissertation begins with a discussion on electrothermal modeling of HVDC cable joints during steady-state and transient operations. A freely available electrothermal solver is implemented, specifically tailored for HVDC cable joint simulation. The solver addresses challenges such as field- and temperature-dependent material properties and the multi-rate nature of the transient electrothermal problem. It is validated against commercial software using a 320 kV HVDC cable joint specimen, with brief analyses conducted for both steady-state and transient operations. The dissertation focuses on developing simulation tools for efficient sensitivity computation, which are vital for design and optimization. Two complementary methods for sensitivity computation are implemented: the direct sensitivity method, which scales with the number of investigated design parameters, and the adjoint variable method, which scales with the number of investigated quantities of interest but is independent of the number of design parameters. The derivation of the adjoint variable method for transient electroquasistatic-thermal problems represents a core contribution of this thesis. The dissertation also demonstrates how simulation can estimate model parameters from experimental data using an inverse problem approach, highlighting the role of measurement data quality. It discusses factors such as measurement sensitivity, data points, and noise corruption. Finally, the dissertation provides a comprehensive literature review on modeling and simulation approaches for slow polarization processes in HVDC cable joints. This chapter reviews various methodologies from the literature, aiming to enhance the accuracy of simulations and analyses for HVDC insulation systems exposed to prolonged unidirectional electric fields. By providing tools for simulation-aided design, this dissertation aims to enable more effective and reliable approaches to HVDC cable joint development. In doing so, it supports the broader goal of improving energy transmission infrastructure and contributing to a stable and sustainable energy supply. |
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| Alternatives oder übersetztes Abstract: |
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| Status: | Verlagsversion | ||||
| URN: | urn:nbn:de:tuda-tuprints-289492 | ||||
| Sachgruppe der Dewey Dezimalklassifikatin (DDC): | 600 Technik, Medizin, angewandte Wissenschaften > 621.3 Elektrotechnik, Elektronik | ||||
| Fachbereich(e)/-gebiet(e): | 18 Fachbereich Elektrotechnik und Informationstechnik 18 Fachbereich Elektrotechnik und Informationstechnik > Institut für Teilchenbeschleunigung und Theorie Elektromagnetische Felder |
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| Hinterlegungsdatum: | 10 Jan 2025 13:05 | ||||
| Letzte Änderung: | 15 Jan 2025 13:35 | ||||
| PPN: | |||||
| Referenten: | Späck-Leigsnering, Dr.-Ing. Yvonne ; Koch, Prof. Dr. Myriam ; De Gersem, Prof. Dr. Herbert | ||||
| Datum der mündlichen Prüfung / Verteidigung / mdl. Prüfung: | 20 November 2024 | ||||
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| Suche nach Titel in: | TUfind oder in Google | ||||
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