Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Solving the problems of electric motors run from power converters

09.12.2003


In this PhD thesis, Eugenio Gubía proposed a solution for the problems of electric motors run from power converters. Controlling motors and electric generators by means of power converters has negative effects with the presence of overtvoltages and high-frequency currents throughout the installation. These effects accelerate the ageing process of the motors and, moreover, can provoke faults in the correct operating of the control circuits.



Thus, in his PhD, Mr Gubia has developed a generic method that can be adapted to each one of the possible installations with the view to identifying the origin of the high-frequency problems and, moreover, to analyse possible solutions. Likewise, the proposed method can be adapted to the design stage of a new installation.
In order to design this method, it was necessary to set up simulation models to reproduce the behaviour of motors, transformers, cables and the power converter, using frequencies in the order of 10 megaHertz. These frequencies are much higher then the tens of kiloHertz used in classical models.

Concretely, in this work it has been possible to reproduce the overvoltages produced as a result of using long connection cables between the inverter and the motor given that, the longer the cable, the greater the probability of overvoltage. This type of cable can be found, for example, in wind-powered generators, which incorporate the generator (the motor) in the upper part of the structure and the power converter at the base.



Also in this thesis, the problem of earthing currents in the installation and the supply grid was investigated, a problem known as electromagnetic interferences or conducted EMI. These have become highly important of late as they can provoke a fault in other units connected to the same earthing system. In fact, the regulations which limit the amount of such currents are increasingly stricter.

Eugenio Gubía has put forward that solutions to both problems, overvoltages and interferences, require the use of filters, the study of which, in this work, has been approached from a perspective of wave theory in transmission lines.
If the electromagnetic interferences do not have a technique or device for their quantification at the heart of the operation, neither can the efficacy of the filters applied to eliminate said effects be measured.

To this end, the work developed in this PhD offers a precise methodology for the analysis of both overvoltages and electromagnetic interferences and that, moreover, enables an efficient filter design.

The author of the thesis is currently researching the possibility of applying this methodology to other fields of power electronics.


Contact :
Iñaki Casado Redin
Nafarroako Unibertsitate Publikoa
inaki.casado@unavarra.es
(+34) 948 16 97 82

Garazi Andonegi | Basque research
Further information:
http://www.basqueresearch.com/berria_irakurri.asp?Gelaxka=1_1&Berri_Kod=370&hizk=I
http://www.unavarra.es

More articles from Power and Electrical Engineering:

nachricht Producing electricity during flight
20.09.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht Solar-to-fuel system recycles CO2 to make ethanol and ethylene
19.09.2017 | DOE/Lawrence Berkeley National Laboratory

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

Im Focus: Silencing bacteria

HZI researchers pave the way for new agents that render hospital pathogens mute

Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Molecular Force Sensors

20.09.2017 | Life Sciences

Producing electricity during flight

20.09.2017 | Power and Electrical Engineering

Tiny lasers from a gallery of whispers

20.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>