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Thesis Work - E-machine experimental study on insulation materials

Thesis Worker at Volvo Cars

Welcome to explore the world of Volvo Cars by writing your thesis with us! As a thesis worker in our organization you are supported by a supervisor who follows you during your project. All thesis projects are arranged in business critical areas and therefore you will be able to contribute to our company purpose – providing freedom to move in a safe, sustainable and personal way – from day one! 



A Comparative Experimental Study on Insulation Materials Developed for Hairpin Winding


The Electric Drive department 97700 at Volvo Cars is proud of being responsible for designing and delivering system solution and functionality for the inverters, electric machine, and transmission, in our electrified vehicles. 
Our vision is to become “Leading in electrification” and we are aiming to contribute to world class energy efficiency, E-machine functionality, sustainability, customer satisfaction and best performance and drivability, to all our future products.


The target of this study is to evaluate different primary insulation materials used in the hairpin winding of the electrical machines for e-mobility applications.   


It is expected to have two billion vehicles in the world by 2035. Having part of them electrified results in hundreds of million traction motors in the range of 50-500 kW running electric vehicles. Consequently, it is of vital importance to design and produce efficient, in terms of energy, reliable and compact propulsion systems including the traction motor. The need for more compact and at the same time efficient propulsion systems has led to proposing converters with a high switching frequency. However, this increases in switching frequency applies more electrical stresses on the traction motor insulation system. 

A high number of research activities in both academia and industry are done with the aim of evaluation and highlighting benefits of employing high switching frequency converters in e-mobility applications. However, the impact of these developments on the traction motor performance and lifetime is not well investigated. 


One may suggest increasing the insulation thicknesses to cope with the increased electrical stresses due to the high dv/dt when using converters with higher switching frequencies. However, using thicker insulation reduces the slot fill factor and, in turn, fundamental losses increase which may cancel out fully or partly energy and efficiency benefits of having converters with a higher switching frequency. Consequently, development and verification of advanced high-performance, thin, and cost-effective insulation systems are necessary. Previous tests were carried out on the tape-based solutions. In this new study, it is planned to take the next step and evaluate different material concepts comparing tape-based solution with enamel-based and PEEK solutions.
The results of this research will be used in the next generation of electrical machines for BEVs.


The main objective of the thesis work can be categorized as follows:
•    Literature study on the insulation systems and test methods.
•    Make the insulation test setup available in Chalmers University of Technology Lab operational and start running some test measurements verifying functionality of the setup and further improve it.
•    Do a simulation study on the experimental setup to better understand the setup logic and improve it.
•    Run voltage endurance tests on the copper samples insulated by different insulation systems provided by VCC. Such as tape-based conductor insulation, enamel-based conductor insulation and PEEK
•    Production of final report.

You are studying Master's in Electrical engineering or similar, including E-machine courses. Your experience using FEM is highly valuable.
• The duration of the thesis work is approx. 4-5 months onsite VCC.
• It starts in spring 2022, exact date to be discussed.
• 30 ECTS (academic credits) in agreement with your University.
• Number of students: 2, working in pair.    
• Computer and software will be arranged by the University and Volvo Cars. 


How to Learn More and Apply 
Selection will be ongoing during the application period, so do not hesitate to send in your application. Attach your resume and cover letter and copies of grades. You can provide a reference if you would like. Please note that due to GDPR, applications by email will not be accepted. If you have any additional questions regarding the position, you are welcome to contact: Thesis supervisor: Bharadwaj Raghuraman, bharadwaj.raghuraman@volvocars.com or hiring manager: Anders Thulin, Anders.Thulin@volvocars.com

We would appreciate your application at the latest by 2021-11-07


Who are we?

Everything we do starts with people. Our purpose is to provide freedom to move, in a personal, sustainable and safe way. We are committed to simplifying our customers’ lives by offering better technology solutions that improve their impact on the world and bringing the most advanced mobility innovations to protect them, their loved ones and the people around them. 

Volvo Cars’ continued success is the result of a collaborative, diverse, and inclusive working environment. The people of Volvo Cars are committed to making a difference in our world. Today, we are one of the most well-known and respected car brands, with over 40,000 employees across the globe. We believe in bringing out the best in each other and harnessing the true power of people. At Volvo Cars your career is designed around your talents and aspirations so you can reach your full potential. Join us on a journey of a lifetime as we create safety, autonomous driving and electrification technologies of tomorrow.

Gothenburg, Sweden

Job requisition ID:  54607

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