High Voltage Laboratory - Budapest University of Technology and Economics

School of Insulation Engineering - today known as the School of Insulation Diagnostics, 1961

The appearance of (electrical) insulation engineering as an independent field of education and research is closely associated with János Eisler. In 1961, the School of Insulation Engineering was established, today known as the School of Insulation Diagnostics.

🔬 Initially, research focused on investigating the electrical properties of insulating materials and developing non-destructive testing methods. Later in the 20th century, the work of Tibor Horváth, Endre Németh and András Csernátony-Hoffer laid the foundations for detailed investigations into dielectric and charge accumulation phenomena, dielectric strength and breakdown phenomena, and the degradation processes of insulating materials. With the development of insulation diagnostics, research associated with the Laboratory increasingly shifted towards comprehensive condition assessment of insulating materials, the investigation of ageing processes, and the estimation of the expected operational lifetime of insulation systems.

🌍 An important milestone in the field’s international presence was the International Conference on Dielectrics and Insulation (ICDI), held in Budapest in 1997. More than twenty years later, in 2018, Budapest also hosted the 2nd IEEE International Conference on Dielectrics (ICD), in the organization of which researchers from the BME High Voltage Laboratory played a major role.

🎓 These two conferences in Budapest demonstrate that insulation engineering, which emerged as an independent field of research in 1961, and the insulation diagnostics that subsequently developed from it, remained an internationally active research area of the Laboratory for decades. Teaching and research have remained an important part of our work ever since, and we regularly participate in national and international collaborations.

🏆 CIGRE Fellow 2026 – Congratulations to Németh Bálint!
We are proud to share that Balint Nemeth, Chairman of CIGRE Hungary National Committee has been recognized as a CIGRE Fellow 2026.

The CIGRE Fellow award recognizes professionals who demonstrate active and outstanding participation in the technical work of CIGRE Study Committees and who take on leading technical roles within the CIGRE community.

Balint has made significant contributions to the international technical work of Study Committee A2 (Power Transformers and Reactors) and Study Committee B2 (Overhead Lines). He has also served as a Task Force Leader and Convenor of several Working Groups, demonstrating outstanding technical leadership and commitment to the CIGRE community.

🏛️ Moving into the V1 Building

Although construction of the buildings for the Faculty of Electrical Engineering began as early as 1951, the departments had to wait until 1959 to move into their new home at 18 Egry József Street, the V1 Building.

⚡ At this time, the Department of Electrical Power Systems and Railways, headed by László Verebélÿ, also moved from the FE Building to the V1 Building. However, the new building was not yet fully completed: the hall of the High-Voltage Laboratory, connected to the V1 Building, the library above it, and the teaching rooms were only completed by 1961. The cross-wing perpendicular to Egry József Street – today’s V1 C wing – housed the Electrical Machines Laboratory, while the level below was occupied by the Electrical Equipment Laboratory.

The “mysterious” relief can still be seen today on the eastern wall of the High-Voltage Laboratory, above the iron gate. To this day, we do not know exactly what the work of the unknown artist illustrate 👀 – but one thing is certain: there are lightning bolts in it.

During the first 90 years of the High Voltage Laboratory, numerous distinguished university experts contributed to the laboratory’s development, professional achievements, and international recognition. From among the most influential figures of this exceptional professional community, we would like to present a few individuals, briefly outlining their work and their role in the history of the laboratory. The third person in this series is János Eisler.

János Eisler (1907–1981)
mechanical engineer, university professor at BME,
Dean of the Faculty of Electrical Engineering (1954–1957),
Head of the Department of High Voltage Technology and Equipment (1961–1967),
founder and head of the School of Insulation Technology (today the School of Insulation Diagnostics) (1961–1972)

He was a dean, department head, and specialist in electrical insulating materials and the testing of electrical insulation systems. He laid the foundations for theoretical research in high-voltage engineering and insulation technology, and initiated the development of non-destructive testing methods for insulating materials.

"Professor Eisler was a strict yet quiet and soft-spoken instructor. On one occasion, in the K building during a “Switchgear Devices” lecture, I arrived late twice. Both at the beginning of the lecture and after the break, I had to make the entire row stand up in order to reach my seat. He endured it without a single word."

"During examinations, he was patient and extremely understanding with students. According to 'Vicinális dugóhúzó', the humorous university magazine, it was good to take exams with Professor Eisler. If someone knew only the chapter titles, they already received a good grade; knowing only the subject title meant a satisfactory grade; and even knowing one’s own name was enough for a sufficient mark. (Note: I myself received a grade of four in his exam!)"

The development of lightning protection science in Hungary in the 20th Century – Budapest Lightning School from 1948

The scientific foundations of lightning research were established in the 18th century, when advances in the understanding of electricity transformed lightning from a mysterious natural phenomenon into a physical process that could be systematically studied. Research carried out over the following centuries laid the groundwork for lightning protection to evolve into an independent field of engineering. Building upon these scientific achievements, the Budapest Lightning School was founded in 1948.

During the first half of the 20th century, one of the principal objectives of László Verebély's research was to understand how the extremely high-energy electrical effects generated by lightning strikes could be safely managed and dissipated, and how buildings, electrical equipment, and power systems could be protected against their damaging consequences.

As a result, lightning protection gradually evolved beyond practical installation techniques into a scientific discipline founded on engineering calculations, physical models, and the principles of electrical engineering.

The most significant lightning protection achievements of the researchers of the High Voltage Laboratory during the 20th century include:
⚡ The probabilistic description of lightning strike locations and the Probability-Modified Attractive Space (PMAS) theory, enabling the quantitative assessment of lightning protection system performance and associated risks.
⚡ The development of the Rolling Sphere Method, which established a new approach to the design and verification of lightning protection systems and has since become an internationally recognized engineering method.
⚡ The introduction and advancement of the multi-stage (cascaded) surge protection concept, which has played a significant role in international standardization and university education.

The decades-long work of the Budapest Lightning School continues to influence lightning protection research, engineering practice, and the development of safe electrical systems around the world.

🚣‍♂️ Across the Icy Danube by Boat: László Verebélÿ's Mission at the War-Torn Technical University

In November 1944, before the Siege of Budapest, valuable laboratory equipment from the Technical University was to be transported to Germany to "protect" it from the destruction of war. Professor László Verebélÿ strongly opposed the removal of the High Voltage Laboratory's equipment. Thanks to his determined intervention, the instruments—although already packed for shipment—remained at the university.
After the siege of Budapest, when the city's bridges had been destroyed, Verebélÿ crossed the icy, ice-choked Danube by boat to reach the university campus in Buda. Walking through the bomb-damaged buildings, he assessed the devastation and found that the vast majority of the laboratory equipment had survived the siege intact. 🛶
The danger, however, was not yet over. The laboratories were left unguarded and were at risk of being looted. Verebélÿ therefore sought out General Zamercev, the Soviet military commandant of Budapest, and requested armed guards to protect the university's laboratories. His request was granted, helping to preserve most of the valuable scientific instruments. 🛡️
Verebélÿ later played a key role in reorganizing the university as its rector. Thanks to his leadership, not a single academic semester was lost at BME despite the war, ensuring that future generations of engineers could continue their education. 🎓

⚡📣 Impulse Generator Since 1943 – The Foundation of Lightning Research at BME

In 1943, the High Voltage Laboratory at BME commissioned an AEG 1 MV impulse generator (also known as a surge generator), designed to produce artificial lightning impulses. Since then, it has remained one of the laboratory's most iconic pieces of equipment and has played a defining role in its history.

The main components of the system include:
⚙️ DC power supply
⚙️ Voltage multiplier unit
⚙️ Control panel
⚙️ Grounding and short-circuiting unit
⚙️ Manual grounding rod

The system operates by supplying adjustable DC voltage to the voltage multiplier, a network of capacitors and resistors that generates lightning impulses with the required waveform. The maximum impulse voltage is controlled by adjusting the spark gap distance between the capacitor system. Safe operation is ensured by the grounding and short-circuiting unit, which automatically grounds and short-circuits the system when it is switched off, while the control panel enables safe operation of the equipment.

⚡ This impulse generator laid the foundation for decades of lightning and lightning protection research at the laboratory—research that continues to play an important role in both scientific investigation and engineering education today.

BME High Voltage Laboratory at the IEEE ICD 2026 Southampton – what an event with amazing presentations, conversations, and a flawless organisation by the team of the University of Southampton.
Dr Ádám Tamus, Dr Richárd Cselkó, and Dániel Balogh represented the High Voltage Laboratory at the International Conference on Dielectrics, organised by the IEEE Dielectrics and Electrical Insulation Society. The topics of our papers included dielectric behaviour of cables exposed to radiation, packaging materials of power semiconductors, recycling of high-voltage cables, and composite insulation diagnostics. Two papers were published in cooperation with the University of Bologna, one of which also involved BME’s Electron Devices Department, and one with the Cablegnosis EU Horizon project. Dr Tamus chaired an oral session, while Dr Cselkó led a poster session. Dr Tamus was also a member of the Technical Program Committee.

⚙️ Operating for nine decades and still performing flawlessly!

At the BME High Voltage Laboratory, a Ganz-manufactured 250 kV single-phase test transformer (nominal voltage 440/250 000 V, power 40 kVA), installed in 1936, is still in operation today. It survived World War II, the Siege of Budapest, the relocation of the university, and the passing of decades, and it continues to serve both student education and scientific research. Naturally, with a fully reconstructed power supply, protection, and control.
Today, the transformer is used several times a week for student laboratory measurements. In addition, the laboratory regularly performs industrial testing services, equipment examinations, and standardized measurements. As a result, this ninety-year-old transformer remains active and continues to play an important role in education, research, and industrial services. 🏛️⚡

We are proud to see our colleagues from the High Voltage Laboratory contributing to the success of ICLP 2026 in Sapporo.

Their active roles in the Technical and Scientific Committees reflect the international recognition of their expertise and commitment to advancing lightning protection research.

Congratulations to Dr. István Kiss and Dr. György Kálecz for representing our laboratory and scientific community at this prestigious event.