On the Design of Ultra-fast Electro-Mechanical Actuators
2013 (English)Licentiate thesis, monograph (Other academic)
The continuously increasing demand for connecting electric grids with remote renewable energy sources such as wind power and photovoltaic cells has rekindled interest in high voltage direct current (HVDC) multi-terminal networks. Although HVDC networks have numerous benefits, their adoption relies entirely on the availability of HVDC circuit breakers which, compared to traditional alternating current circuit breakers, have to operate in a time frame of milliseconds.
This thesis deals with the design of ultra-fast electro-mechanical actuators based on the so-called Thomson coil (TC) actuator. The simulation of a (TC) actuator constitutes a multi-physical problem where electromagnetic, thermal, and mechanical aspects must be considered. Moreover, it is complex since all those variables are co-dependent and have to be solved for simultaneously. As a result, a multi-physics simulation model that can predict the behavior and performance of such actuators with a high degree of accuracy was developed.
Furthermore, other actuator concepts were also investigated and modeled in light of searching for a drive with a superior efficiency. The theory behind the force generation principles of two different types of ultra-fast electromechanical actuators, the TC and the double sided coil (DSC), were compared by the use of static, frequency, and comprehensive transient multi-physics finite element simulation models.
Although, simulation models serve as a powerful tool for modeling and designing such state of the art actuators, without validation, they are weak and prone to errors since they rely on approximations and simplifications that might not always hold. Therefore, a prototype was built in the laboratory and the model was validated experimentally.
Finally, it is important to note that the drives in this thesis are intended to actuate metallic contacts. As such, their behavior and performance upon mechanical loading was studied. Furthermore, some scaling techniques were applied to boost their performance and efficiency.
Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2013. , viii, 68 p.
Trita-EE, ISSN 1653-5146 ; 2013:015
Electro-mechanical drive, Circuit breakers, HVDC transmission, Eddy currents, Finite element, Electromagnetic, Thermal, Mechanical, Coils, Armature, Image motion analysis.
Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:kth:diva-121181OAI: oai:DiVA.org:kth-121181DiVA: diva2:617236
2013-05-08, F3, Lindstedtsvägen 26, KTH, Stockholm, 14:00 (Swedish)
Lembke, Torbjörn, Dr.
Engdahl, Göran, Professor
QC 201304222013-04-222013-04-222013-04-22Bibliographically approved