Partner: IJS – Institut Jožef Stefan
MAHLE Electric Drives Slovenia d.o.o. with its headquarters and production premises in Šempeter near Gorica, is part of the global concern MAHLE GmbH from Stuttgart and is an internationally established manufacturer of starters and alternators for internal combustion engines, autonomously powered DC electric drive systems and other more demanding components for the automotive industry.
In the development of its products, the company uses the most modern approaches and cooperates with research institutions. Both also apply to the development project of a synchronous electric motor with surface-mounted magnets, which is part of a car’s power steering system. The goal of the project was the techno-economic optimization of the electric motor, i.e. determining the geometry and material properties of its components so that the electric motor meets all technical requirements and its price is minimal.
The search for a solution was undertaken in cooperation with researchers from the Department of Intelligent Systems and the Department of Computer Systems at the “Jožef Stefan” Institute. In this, the company and researchers were assisted by the colleagues of the Service for Substantive Project Support, Technology Transfer and Innovation and the Service for Connecting with the Economy at the “Jožef Stefan” Institute, who initially identified the key technological and development challenges of the company, and then established contact with both research in two sections based on their expertise and knowledge for the development of a technological solution adapted to the company. They also supported the researchers in preparing possible approaches and ways to solve the company’s technological challenge, including negotiations and formal aspects of entering into cooperation, as well as from the point of view of intellectual property issues.
As part of the cooperation, a computer-aided iterative optimization procedure was developed, connected to a numerical simulator of possible solutions using the finite element method. Here, the key challenge was the high computational complexity of the simulations and, consequently, the entire optimization process. We have therefore upgraded this with several ways to speed it up: with fast-calculating replacement models, parallelization of the optimization algorithm and evaluation of solutions in several steps, which enables the elimination of certain inadmissible solutions without a computationally demanding simulation. The next challenge was the need to ensure the robustness of the solution, taking into account tolerance deviations in the manufacture of electric motors. We ensured this by evaluating admissible solutions in the optimization process on a sample of implementations with different deviations. Finally, in addition to the numerical results, we also wanted to gain an insight into the space of possible solutions and thus a better understanding of the problem. We achieved this by incorporating data analysis and visualization methods into the optimization environment.
Key to the development of the solution was the mastery of metaheuristic optimization methods with replacement models, computationally intensive procedures, and data analysis and visualization by the participating researchers, while members of the project team from the company contributed knowledge about electric motors and their planning, starting points for the optimization process, and software and licenses to calculate the electromagnetic model using the finite element method.
The result of the cooperation is the electromagnetic design of the active parts of the electric motor, determined by the values of its dimensional and material parameters. The obtained values of these parameters ensure the rational use of components, the maximum possible fulfillment of customer requirements regarding the characteristics of the electric motor and its affordability. This optimized electric motor has a 10% lower component price compared to the base version. Considering the fact that several million pieces are produced during the entire production period of such a product, this represents a significant saving for the company and greatly improves their competitiveness in the market.
For this achievement, MAHLE Electric Drives Slovenija d.o.o. and the ”Jožef Stefan” Institute at the IRT 2023 Industrial Forum in Portorož received the TARAS award for the successful cooperation of the economy and the research and development environment in the field of innovation, development and technologies.
The project was directly financed by the company MAHLE Electric Drives Slovenija d.o.o. The Service for content support for projects, the transfer of technologies and innovations, and the Service for connecting with the economy at the “Jožef Stefan” Institute made a key contribution to the establishment of cooperation.