In teaching, we have expanded from a single diploma programme in electrical engineering with eight specialisations in the 26 years since 1997 to several two-part programmes (separated into Bachelor's and Master's programmes) by 2023. In my opinion, this enormous expansion of the range of courses with only a slight increase in the number of professors and staff could only be realised through a massive expansion of digital support for the administrative workload.

In research, third-party funding has increased massively over the past 26 years compared to state funding. This has naturally meant that our own interests in research topics have had to be subordinated to the interests of the funding bodies to a certain extent. In a positive sense, however, many new research topics have been added (e.g. medical technology, methods of artificial intelligence for electrical engineering applications, new material applications for electrical engineering and information technology), without the “old” topics losing any of their importance. The origins of the doctoral students have become much more international, partly because domestic young researchers are rare.

There are quite a few: First, three departments – 17 (Energy Technology), 18 (Communication Technology) and 19 (Data Technology) – were united into a single department, today's Department 18 (Electrical Engineering and Information Technology, etit for short). This was associated with various challenges, such as a change in funding for the departments, and most recently the addition of several professorships in the field of medical technology.

Second, the conversion of the TU Darmstadt to an autonomous university with sovereignty in all financial and administrative areas, which meant, for example, that I was no longer a civil servant of the state of Hesse, but a civil servant of the TU, from which I now receive my pension.

Third, massive changes in teaching such as the conversion of the diploma programme to the Bachelor's and Master's system, the introduction of accreditations and re-accreditations of study programmes every five years, also the introduction of the new interdisciplinary study programmes Mechatronics (together with Mechanical Engineering) Information Systems Engineering (together with Computer Science). Medical Technology (together with Medicine at Goethe University Frankfurt, Energy Science and Engineering (together with various departments of the TU) as well as the international Master's programmes Information and Communication Engineering and Electrical Power Engineering. The latter has since been discontinued.

Fourth, the introduction of the junior professor:in position, which meant that the “habilitation” career path lost some of its importance.

Fifth, since 1997 enormous funds have been invested in the then urgently needed structural renovation of the TU Darmstadt, which shortly before was still called TH Darmstadt – with numerous new buildings such as the ULB, the Civil Engineering Centre, the Lecture Hall Centre and new laboratories on the Lichtwiese, the etit deanery building, the Welcome Hotel and the Karo5, the new building next to it with the student café or the building for international encounters now in progress. In addition, numerous buildings were extensively renovated, such as the Otto Berndt canteen, the castle for the new university management and – concerning our institute itself – our laboratory building, so that after 20 years it finally no longer rains into our two laboratories.

I'm sticking here with my field of expertise, electrical energy conversion. Here I see four milestones. The energy turnaround with the introduction of modern wind generator technology up to today's 16 megawatts (from approx. 0.5 megawatts at the time) with approx. 6 tonnes of magnetic material in a gearless 12 megawatt generator and a wind turbine height of 80 per cent of the Eiffel Tower – whereby we have been involved in several industrial projects, such as the design of a large underwater tidal generator in the megawatt range for submarine operation off the Scottish coast with two German industrial partners.

The third wave of electromobility, after the first in the 1980s and the second in the 1990s petered out. We accompanied the special development of the highly compact e-motors with novel hair-pin windings, special cooling methods with oil or glycol, novel rotor design with reluctance effects and magnets and a new recycling strategy with projects. To this end, we have carried out several large-scale multidisciplinary projects with the Department of Mechanical Engineering and industry. I fondly remember the design of e-bikes as project seminars with students when e-bikes were still in an early development and research phase.

The digitalisation wave Industry 4.0 with its mechatronic penetration of power electronics, e-motors and gearboxes for modular plug-and-play applications. This brought new problems in the networked system with parasitic high-frequency interference currents that destroyed the ball bearings in the motor and gearbox and the winding insulation in the e-motor. By founding a long-standing multidisciplinary industrial-university research group, we were able to carry out numerous studies on parasitic effects, some of which involved several years of long-term experiments in our laboratory, and for many years we operated a DFG-funded research group with four professors from the department.

High-speed drives with magnetic bearings: In several projects, among others with the Hessian industry, we have designed, theoretically investigated and practically optimised drives in our own laboratory, which allow the driven compressor units to be as small as an exhaust gas turbocharger impeller for larger outputs of up to approx. 40 kW at speeds of up to 60,000 per minute. The magnetic bearing thus moved from its special niche existence into the broader application of getting high performance out of a small motor and compressor volume without wear, loss or noise, which we were also able to demonstrate at the Hannover Messe Industrie. Together with mechanical engineering, as a researching group of four professorships, we have advanced the integrated motor-pump design.

There were three major challenges in teaching: With a constantly increasing volume of knowledge, but limited teaching hours, how can the current knowledge of electrical energy conversion be conveyed to young people in a sound yet compact manner? My solution: appropriate scripts and literature for self-study.

How can young people, who have grown up mostly with laptops and mobile phones, be sensibly introduced to and enthused about measurement technology, constructive design, laboratory experiments even at high current, high voltage, high power and speed with all their potential hazards? My solution: through hands-on workshops and design projects. Of course, this requires the appropriate, expensive equipment.

How can the connection to later professional practice be established early on in the degree programme, now that the compulsory professional internships in the B.Sc. and M.Sc. have been abolished? My solution: lecturers from industry. Plus lecturers from partner universities to cover as wide a range of topics as possible in teaching.

I see four challenges in research: The theoretical penetration of technically relevant questions. For example, what design possibilities arise when the drive of the ICE high-speed train is switched from conventional asynchronous to innovative magnetic technology?

The scientifically sound participation in large-scale industrial projects with novel developments, such as the development of permanent magnet-excited generators without gears for the energy turnaround.

The advancement of technically innovative ideas so that they can be put into practice. One example is the further development of the “bearingless” electric motor to achieve higher outputs. With this principle, the magnetic bearing for magnetic levitation disappears; the electric motor itself takes over this levitation function. We have built prototypes for this purpose in order to test them experimentally in our own laboratory.

The development of technically feasible concepts for the energy-saving use of new technologies for electrical energy conversion, for example. the use of second-generation high-temperature superconductors, which have been further developed for ten years, as strip conductors for the electrical windings in e-machines for wind generators or electrically assisted flying.

I was hired for their training, so they were and are the central group of people for whom I went “to work” every day. I got to know many of them during the annual “one-week excursions” in power engineering, and was thus able to recruit some of them as staff members, even though our “theory and lab” requirement means a lot of work on average, which has gotten around.

As spokesperson for the former specialisation “General Electrical Engineering”, the former “EPE course”, as spokesperson for the specialisation “Electrical Power Engineering” and the specialisation “Mechatronic Drives”, as head of the then teaching and study committee of the department etit (now Dean of Studies), as Dean of Studies for the vocational teacher training and conversion of this course to B.Sc.- M.Sc. courses and as the responsible head of the energy technology training workshop at the department for over 20 apprentices in three and a half apprenticeship years, I had a lot of contact with students and also with our apprentices, which kept me young.

For me, the closer contact resulted from the oral examinations, which were still compulsory in the past and which directly followed the written examinations as part of the respective overall examination. From 2010, these oral examinations were changed to purely written examinations due to work overload, so that personal contact now took place during the seminar lectures, B.Sc. and M.Sc. lectures, during the excursions and during the HiWi work at our institute.

The seminars on converting a bicycle into an e-bike with a test drive, the Advanced Design Projects with engine construction and measurement, but also the energy technology summer party with barbecue and the energy technology excursions are particularly memorable to me.

I like to think of the festive colloquia organised by our institute in honour of my predecessor and former vice-president of the TU Darmstadt, Prof. Egon-Christian Andresen, and also of the ceremony to mark the 150th birthday of the inventor and e-pioneer Michael von Dolivo-Dobrowolsky, who worked at the TU Darmstadt.

For my 60th birthday, I was surprised by our staff with a wonderfully organised scientific colloquium in the Lichtenberghaus, with a large audience and many alumni as speakers. The Institute's company outings to the surrounding areas in Hesse and the Palatinate in summer and the Christmas party trips to the Christmas and Christmas markets in winter are also unforgettable experiences.

The honours with awards for capable students and doctoral candidates of our institute at the university, but also externally, for example at the industrial SEW Foundation, at the VDE/ETG, at the ICEM conference were also very uplifting and confirmed the high-quality content of our achievements.

The memories of the time with Humboldt fellows from Montenegro and Nigeria, with scientific guests from Romania, Austria, Switzerland and Japan, among others, and above all the joint doctoral seminars with the E-Machine Chair of TU Dresden in many places in Germany and in the Kleines Walsertal valley in Austria with many souvenir photos will accompany me.

But I also remember many scientific successes at the TU itself: successful doctoral examinations with awards or the inauguration of the student laboratory for e-drives, which we renovated with external help and funding from HSP2020, by Chancellor Manfred Efinger five years ago.

Anyone who is committed to a good cause and remains faithful to its progress, who does not allow himself to be distracted by any kind of adversity, but who persistently continues on his path once it has been recognised as the right one, without making great demands on his own person, can achieve a lot of good. This very general experience is a recipe for life that is valid for me regardless of a specific activity.

With my successor Prof. Dr.-Ing. Yves Burkhardt, who brings both university and industrial experience, with research, teaching and management experience, the future of electric drive systems at TU Darmstadt is in good hands. There are enough research topics. The continuation of already initiated topics alone is life-filling. The lack of qualified junior staff places teaching, which is of a high quality, in a strategically important position for modern society.

Due to the rapid growth of the world's population and the associated challenges of supply, strong urbanisation, migratory movements, and the increasing demands of many, a rapidly advancing mechanisation of our humanity is necessary in order to find suitable solutions for all of this. This will not be possible for the general public with a “back to nature like Robinson”, but only if the tasks at hand are also mastered with the support of resourceful engineering.

For today's young people with an interest in technology and the natural sciences, this describes a broad and vital field of activity, so that I have no fears for the professional future of our students – if they are prepared to face the challenges. This applies to a similar extent to all those who see their professional future in researching technical and scientific contexts.

Even if some questions do not immediately show their application in practice, working on them has often paved the way for new solutions. However, even if more and more technical aids are available to us and thus to the young people of today to solve the tasks, I wish and hope that independent thinking, the breaking down of complicated facts to simplified basic schemata, the “looking behind” and the “wanting to understand” may always come first.

And above all, that a mutual respect and a healthy dose of humility towards life may always and above all be guarded in the hearts of the young, as hopefully was the case with us old people, even if one may not always have noticed it immediately.