Manfred Depenbrock

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Manfred Depenbrock (born January 11, 1929 in Bielefeld ; † January 30, 2019 in Bochum ) was a German electrical engineer . He is considered to be the inventor of various processes in converter and drive technology for three-phase machines . He also justified the representation of reactive power definitions in electrical multi-conductor systems.

Life

Private life

Depenbrock was born as the eldest son of August and Maria Depenbrock in Bielefeld and grew up with his two younger siblings Helga and Klaus in Brackwede. After graduating from high school, he studied electrical engineering at the Technical University in Hanover, where he met his wife Elly in 1954, whom he married after graduating in 1955. The couple had two children, Antje and Katrin. He was particularly proud of four grandchildren and one great-grandson. In 2015 his wife Elly died.

Working life

Depenbrock joined the rectifier department at Brown, Boveri & Cie. In 1954 as a development engineer . (BBC) in Mannheim. In 1962 he received his doctorate externally in Hanover with Prof. Brückner ("Investigations into the voltage and power ratios in converters without energy storage"). At BBC he helped shape the transition from mercury vapor rectifiers to semiconductor converters and was promoted to head of the central electronics development department. In 1968 he followed a call to the newly founded Ruhr University Bochum (RUB) and was the founding professor of the Chair for Generation and Use of Electrical Energy (EAEE), which he headed until his retirement in 1994. In 1982 he was appointed a full member of the North Rhine-Westphalian Academy of Sciences and the Arts .

His concern with the theory of reactive power resulted in the first invention that influenced the power electronics of rail locomotives : The "single-phase converter with sinusoidal mains current and well-smoothed direct quantities", named after its circuit configuration "four-quadrant converter", is considered to be the "enabler" of the three-phase drive technology characterized by voltage- impressing converters such as is used in the ICE . The four-quadrant controller created the possibility of extracting power of over 6  MW from a traction vehicle from the low-frequency rail network with tolerable network feedback , and is now common on AC railways worldwide.

In 1984, Depenbrock's second invention for rail drive technology followed. The direct self-regulation (DSR) of inverter- fed asynchronous motors derives the switching commands for the thyristors of the inverter directly from the values ​​for stator flux and torque, dispensing with subordinate current regulation. Since these values ​​cannot be measured directly, they have to be simulated in a mathematical, non-linear model in the control. Depenbrock was one of the first to use digital signal processors in drive technology. The DSR combines a high level of robustness with high dynamics, with the lowest demands on the always limited switching frequency of high-performance inverters. It was subsequently further developed for high-performance inverters in three-point connection and used, among other things, in the Swiss Re 460 locomotives.

At the end of the 1980s, when an increase in the possible switching frequency due to new components became apparent, Depenbrock developed the indirect stator size control or ISR based on the basic idea of ​​DSR, the orientation towards the stator flux. It uses the new possibilities at the time to combine the advantages of stator flux orientation with the advantages of pulse modulation . Due to its defined current spectra, this is more easily able than the two-point control of the original DSR to meet the extremely high demands on the current harmonic values ​​of traction vehicles on the contact wire, which the track safety technology of the railways makes.

Since DSR and ISR require a so-called complete machine model, they could also serve as the basis for the development of a serviceable speed sensor-free control for rail engines from 1992 onwards. Precise speed encoders, as needed for high-quality control, reduce the otherwise high robustness of three-phase traction drives. The speed sensorless control works without high-frequency test signals and is therefore particularly suitable for high-performance traction drives. Today it is used in numerous electric multiple units.

In addition, Depenbrock expanded the reactive power theory to the "Fryze-Buchholz-Depenbrock method" after his retirement. It describes the mathematical decomposition of the voltages and currents of any multi-conductor system into orthogonal component systems. It found its way into the DIN standard 40110 part 2 as well as into the IEEE standard 1459.

Depenbrock had 57 patents granted and 33 supervised dissertations. Among other things, he was head of the ETG technical committee "Electronics in Energy Technology", as a consultant for the scientific journal etz-A and ETEP of the Association of German Engineers , in the standards committee of the German Commission for Electrical, Electronic and Information Technologies and, last but not least, in the German Research Foundation as a reviewer active.

honors and awards

  • VDI Ring of Honor 1969
  • Heinrich Hertz Prize of the University of Karlsruhe 1987
  • Ernst Blickle Prize of the SEW Eurodrive Foundation 1991
  • VDE honor ring 1998
  • Fellow of the IEEE 1998

literature

  • Schröder, D .: Electric Drives 2, Controls. Springer-Verlag, Berlin, 2001: Chapters 15.5–15.7
  • Steimel, A .: Electric traction vehicles and their energy supply. InnoTech Medien GmbH, Augsburg, 4th edition 2017, 416 pp

Web links

Individual evidence

  1. ↑ Depenbrock, M .: Single-phase converter with sinusoidal mains current and well-smoothed direct quantities. ETZ-A 94 (1973), no. 8, p. 466.
  2. ↑ Depenbrock, M .: Direct self-regulation (DSR) for highly dynamic rotating field drives with power converter supply. etz Archive 1985, no. 7, pp. 211-218
  3. ↑ Baader, U .; Hodapp, J .: Regulation of the induction machine optimized for high-performance traction . Elektro Bahnen 89 (1991), H. 3, pp 73-78
  4. ↑ Gerber, M .; Drabek, E .; Müller, R. The locomotives 2000 series 460 of the Swiss Federal Railways. Swiss Railway Review 1991, no. 10, pp. 321–377
  5. ↑ Hoffmann, F .; Jänecke, M .: Fast Torque Control of an IGBT-Inverter Fed Three-Phase AC Drive in the Whole Speed ​​Range - Experimental Results. 6th European Power Electronic Conference (EPE) 1995, Seville, Proc. Pp. 3.399-404
  6. ↑ Depenbrock, M .; Hoffmann, F .; Koch, St .: Speed ​​Sensorless High Performance Control For Traction Drives. 7th European Power Electronic Conference (EPE) 1997, pp. 1418-1423
  7. ↑ Depenbrock, M .; Foerth, Ch .; Hoffmann, F .; Koch, S .; Steimel, A .; Weidauer, M .: Speed-sensorless stator-flux-oriented control of induction motor drives in traction. Communications - Scientific Letters of the University of Zilina 2-3 / 2001, pp. 68-75
  8. ↑ Depenbrock, M .: The FBD-method, A Generally Applicable Tool For Analyzing Power Relations. IEEE Transactions on Power Systems 1993, H. 2, pp. 381-387
personal data
SURNAME Depenbrock, Manfred
BRIEF DESCRIPTION German electrical engineer
DATE OF BIRTH January 11, 1929
PLACE OF BIRTH Bielefeld
DATE OF DEATH January 30, 2019
Place of death Bochum