PhD candidates in Ageing Mechanisms, Performance, and Reliability of Extruded HVDC Cables

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About the position

Are you motivated to take a step towards a doctorate and open up exciting career opportunities? Do you have a background in electric power engineering, physics, physical chemistry, or material science, and are you interested in high voltage technology and HVDC power cables? As a PhD candidate with us, you will work to achieve your doctorate, and at the same time gain valuable experience that qualifies you for a further career in higher education and research, in and outside academia. 

The Department of Electric Energy (IEL) at NTNU is seeking two highly motivated candidates for two full-time (100%) PhD positions for 3 years as part of the project “Ageing mechanisms, performance, and reliability of extruded HVDC cables - AMPRExDC”. You will join the research group High Voltage Technology at IEL, where we foster an open, inclusive, and collaborative working environment.

Our working environment is characterized by its friendly and supportive atmosphere, with regular gatherings such as professional meetings within the research group, weekly colloquia, shared lunches, and “Friday coffee” sessions to wrap up the week. These formal and informal occasions provide opportunities to exchange ideas, celebrate milestones, and strengthen connections. PhD candidates also arrange social activities, open to everyone who wishes to join, creating a welcoming and inclusive community.

Your immediate Line Manager will be the Head of Department.

About the project

Extruded High Voltage Direct Current (HVDC) cable systems, a newer alternative to traditional mass impregnated HVDC cables, offer benefits like higher conductor temperature, lower costs, and faster installation. They play a crucial role in expanding cross-border transmission to meet energy-saving targets and reduce CO2 emissions. However, despite their advantages, there's limited long-term experience with them, posing challenges for ensuring their longevity and conducting effective condition assessments. 

The lack of established physics-based ageing models for extruded HVDC cables presents a challenge in ensuring their long-term reliability. While extruded cable insulation for AC has been in use for decades, directly applying that knowledge to HVDC stresses is not straightforward. Understanding the intrinsic thermo-electric ageing mechanisms specific to HVDC cables is crucial for predicting their lifespan, which can extend up to 40 years or more. Without well-established ageing models, effective condition assessments are challenging, potentially leading to unforeseen failures and costly repairs. As the adoption of extruded HVDC cable systems increases, there is an urgent need for comprehensive research and development to address this knowledge gap and ensure the continued reliability of HVDC transmission infrastructure.

In the AMPRExDC project, accelerated cable ageing under DC will be studied. Advanced material characterisation of the insulation system and DC-breakdown tests of cable peelings will be done at different stages of ageing to establish a foundation for improved physics- based ageing models. This will be incorporated into new numerical models of the polymer insulation using finite element or equivalent methods. The two PhD candidates will work in close cooperation, but on separate aspects of this:

1. PhD #1 Material characterisation of aged HVDC cable insulation: The PhD work will focus on characterisation and testing of the insulation system, using advanced material characterisation equipment. This will span both thermal, electrical and mechanical characterisation (e.g. space charge measurements, dielectric response in time and frequency domain, TGA, DSC, DMA, FTIR etc.). 
    
2. PhD #2 Numerical modelling of the ageing of HVDC cable insulation: Numerical models of the dielectric to facilitate improved prediction of the long-term ageing of HVDC insulation materials under different types of stresses will be developed. This will include models of the alteration of the structure of the polymeric insulation due to electrothermal ageing (e.g. change in charge carrier availability, development of chemical and physical traps, and change in overall morphology), and linking this to the dielectric properties of the insulation (e.g. increase in conductivity, space charge accumulation, local field distributions around contaminants etc.). The models will be validated against experimental results obtained in the AMPRExDC project. 

The main supervisor for PhD #1 will be Professor Frank Mauseth, with Dr. Caterina Elena Lesaint Rusu (SINTEF Energy Research) as co-supervisor. The main supervisor for PhD # 2 will be Professor Øystein Hestad, with Dr. Torbjørn Andersen Ve (SINTEF Energy Research) as co-supervisor.

Duties of the position

• Carry out research of high quality within the framework described above
• Participate in activities of the research group High Voltage Technology (HVT).
• Complete academic training consisting of coursework corresponding to a minimum 30 ECTS
• Contribute to publications in relevant journals and to popular science dissemination
• Participate in international activities such as conferences and/or research stays at foreign educational institutions 

Be prepared for changes to your work duties after employment.

Required selection criteria

• You must have a Master's degree in electric power engineering, physics, physical chemistry, or material science. Your course of study must correspond to a five-year Norwegian course, where 120 credits have been obtained at Master's level. Master's students can apply, but the master's degree must be obtained and documented before starting the position and no later than 31 August 2025.
• Your course of study must correspond to a five-year Norwegian course, where 120 credits have been obtained at the Master's level. Master's students can apply, but the Master's degree must be obtained and documented before starting the position and no later than 31 August 2025.
• You must have a strong academic background from your previous studies and have an average grade from your Master's degree study, or equivalent education, which is equal to B or better compared to NTNU's grading scale. If you do not have letter grades from previous studies, you must have an equally good academic foundation. If you have a weaker grade background, you may be considered if you can document that you are particularly suitable for a PhD education, i.e., by having relevant work experience and/or published/publishable scientific papers.
• You must meet the requirements for admission to the Faculty's Doctoral Programme.
• You must have Norwegian, Swedish, or Danish language skills corresponding to the scale A2 in the Common European Framework of Reference for Languages (CEFR). If you cannot document those skills upon employment, you must take Norwegian courses corresponding to at least 15 credits before the end of the employment period. NTNU will facilitate this. The Norwegian training comes in addition to the PhD candidate’s three-year doctoral work. The language requirements only apply if a decision on employment in the position takes place from 1 August 2025.  
• You must have English language skills, both written and spoken, corresponding to the scale B2 in the Common European Framework of Reference for Languages (CEFR). Applicants from non-English speaking countries outside EU/EEA/Switzerland must provide preliminary documentation of English language proficiency, in terms of an approved test. One of the following test scores could be documented for this purpose: 
  • TOEFL internet-based test (iBT) - Score equivalent to the B2 level: 79 - 101. 
  • IELTS - Score equivalent to the B2 level: 5.5 - 6.0 
  • Cambridge English - Score equivalent to the B2 level: 160 - 179.

Further assessment of both written and oral English language skills and the ability to communicate fluently will be conducted in the continued selection process and during any interviews for all applicants.

PLEASE NOTE: For detailed information about what the application must contain, see paragraph “About the application”.

As a result of the new Act relating to universities and university colleges with associated regulations of 01.08.2024, NTNU has, during a transitional period (for decisions on employment in recruitment positions before 1 August 2025), chosen to use the terms of employment in the old regulations of 31 January 2006 no. 102 on terms of employment for positions such as postdoctoral fellow, research fellow, scientific assistant and specialist candidate

Preferred selection criteria

• Work and/or research experience in high voltage insulation technique and degradation/ageing of polymeric insulation materials.
• Experience with material characterization of polymeric materials.
• Experience with numerical simulations (Finite Element, Finite volume, and other techniques), and with programming (e.g. Python and MatLab).
• English language skills, both written and spoken, corresponding to the scale C1 in the Common European Framework of Reference for Languages (CEFR). See which scores are equivalent to the C1 level here.

Personal characteristics

To complete a doctoral degree (PhD), it is important that you are able to: 

• Work independently and structured, set goals, and make plans to achieve them 
• Present and discuss your research with other professionals 
• Engage and contribute constructively with feedback 
• Work constructively under pressure or in the face of adversity   
• Show curiosity and have a strong motivation for the subject 
• Analyze data, assess different perspectives, and draw well-founded conclusions   
• Be flexible and open to adjusting the plan for the project as needed 

Emphasis will be placed on personal qualities.

We offer

• An exciting job with an important mission in society
• Developing tasks in a strong and international professional environment
• Career guidance and follow-up during the PhD period
• Open and inclusive working environment with committed colleagues
• Working capital that can be used to implement the project
• Mentor programme as a new employee at NTNU
• As a public employee, you have favourable benefits as a member of the Norwegian Public Service Pension Fund (SPK)

You will be employed as a PhD Candidate at NTNU and will have access to employee benefits and discounts. 

Diversity

Diversity is a strength, and at NTNU we aim to be an employer that reflects the diversity in society and that makes use of the potential of the population's collective skills. Our vision is Knowledge for a better world and our values are creative, critical, constructive and respectful. We believe that an organization that is equal, diverse and gender-balanced is essential for us to achieve our goals. 

We strive to attract employees with different skills, life experiences and perspectives to contribute to even better problem solving of our societal mission in research and education. 

If you think this position is relevant and interesting, we encourage you to apply, regardless of gender, functional ability and cultural background, or whether you have been out of work for a period of time.

At NTNU we want to increase the proportion of women in scientific positions. We have a number of measures to promote equality.

Salary and conditions

In the position of PhD Candidate, code 1017, your gross salary will normally be NOK 536 200,-  per annum depending on qualifications and seniority. A 2% statutory contribution to the State Pension Fund is deducted from the salary. 

The employment period is 3 years for the doctoral work, with the possibility of an additional 6 months or more of employment in connection to duty work. 

The option of duty work may be offered to a candidate with clear motivation and ability for such work, and if the Department sees the need. This will be clarified with the candidate during and after any interview. 

If learning Norwegian (level A2 corresponding to at least 15 credits) is to be completed before the end of the employment period, the employment period can be extended by 10 weeks. The language requirements only apply if a decision on employment in the position takes place from 1 August 2025.

For employment as a PhD candidate, it is a prerequisite that you gain admission to the PhD programme in Electric Power Engineering within three months of your employment contract start date, and that you participate in an organized doctoral programme throughout the period of employment.

The position is conditional on external funding.

As an employee at NTNU, it is important that you keep yourself up to date with academic and organizational changes and adapt to them.

For the necessary academic and social interaction, it is a prerequisite that you are physically present and available to the institution at campus Trondheim on a daily basis.

The appointment is carried out in accordance with the principles of the State Employees Act, and Export control (legislation that regulates the export of knowledge, technology and services). Candidates who, after assessment of the application and attachments, are considered to be in conflict with the criteria in the latter act, will not be able to be employed.

About the application

The attachments (including a description of your scientific work) must accompany the application as these documents form the basis of the application assessment. The documents must be in Norwegian/a Scandinavian language or English. 

Please note: The application will only be assessed on the basis of the information we have received by the application deadline. Therefore, make sure that your application clearly shows how your skills and experience meet the criteria described above. The application and all attachments must be sent electronically via Jobbnorge.no. If you are invited to an interview, you must bring certified copies of certificates and diplomas upon request.

The application must include: 

• A cover letter where the applicant describes personal motivation, summarizing scientific work, and how the applicant sees her/his background as suitable (400 words/1 page). 
  • Note: Please state at the beginning of your cover letter whether you are applying for PhD #1, #2, or both.
• Project outline containing proposals for an overall description of research questions, theoretical perspectives, methodological design for the project, and progress plan (maximum 1500 words/4 pages, including references). This proposal will be neither final nor binding for the project. 
  • Note: If you are applying for both PhD positions (#1 & #2), you must submit separate, distinct project proposals for each of them. 
• CV.
• If you have testimonials of work experience, submit them.
• Transcripts and diplomas for Bachelor's and Master's degrees. If you have not yet completed your Master's thesis, you must provide confirmation on your estimated date for the submission of the Master's thesis, or confirmation that your Master's thesis has been submitted.
  • Applicants from universities outside Norway are requested to send a diploma supplement or a similar document, which describes in detail the study programme and grading system. See also specific documentation requirements for education obtained outside of Norway, applicable to certain regions/countries, here. 
• A copy of the Master's thesis. If you recently submitted your Master's thesis, you are encouraged to attach a draft of the thesis. Documentation of a completed Master's degree must be presented before taking up the position. 
• If you have publications or other relevant research work, submit them.
• English language proficiency documentation.
• Name and contact information of three referees.

If all, or parts, of your education have been taken abroad, we also ask you to attach documentation of the scope and quality of your entire education, both Bachelor's and Master's education, in addition to other higher education. If your institution uses “diploma supplement” (normal for most European institutions), you must attach this. A description of the documentation required can also be found here. If you already have a statement from Norwegian Directorate for Higher Education and Skills (HK-dir), please attach this as well. 

Joint works will be considered. If it is difficult to identify your contribution to joint work, you must attach a brief description of your participation.

When assessing the best qualified, we emphasize necessary qualifications such as education, experience and personal suitability. Motivation for the position, ambitions and potential for research will also count when assessing the candidates.

NTNU recognizes a wide range of academic contributions and has committed itself to The San Francisco Declaration on Research Assessment and CoARA (responsible assessment of research and recognition of a greater breadth of academic contributions in accordance with NTNU's social mission).

General information

A public list of applicants with name, age, job title and municipality of residence is prepared after the application deadline. If you wish to be exempt from entry on the public applicant list, this must be justified. Assessment will be made in accordance with current legislation. You will be notified if the exemption is not granted.

If you think this position looks interesting and in line with your qualifications, you are welcome to apply.

If you have any questions about the position, please contact Professor Øystein Hestad or Frank Mauseth by mail at oystein.hestad@ntnu.no or frank.mauseth@ntnu.no. If you have any questions about the recruitment process, please contact HR consultant Sven Robert Storø by mail at sven.r.storo@ntnu.no.

Application deadline: 31.03.2025

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For practical information about working at NTNU, please visit this webpage. 
 

The city of Trondheim is a modern European city with a rich cultural scene. Trondheim is the tech capital of Norway with a population of 200,000. The Norwegian welfare state, including healthcare, schools, kindergartens and overall equality, is probably the best of its kind in the world. Professional subsidized day-care for children is easily available. Furthermore, Trondheim offers great opportunities for education (including international schools) and possibilities to enjoy nature, culture and family life and has low crime rates and clean air quality.