TRANSACTIONS ON ELECTRICAL ENGINEERING

ISSN 1805-3386

November 19, 2017








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2016 No.2

Method to Control Multiple Segmented LLSM without Position Encoder

Weber, A. R., Steiner, G.

In recent years long stator linear synchronous motors (LLSM) started to replace the typical rotating to linear converters like belts, chains, screw systems, pulleys, disks and so on. With LLSM a lot of drawbacks in the machine concepts and design can be prevented. For long tracks, reducing reactive power and individual control of numerous moveable units, the track is segmented in several fed stator units. Because of the LLSM construction an operation with a physical position encoder is not desirable. For that reason position observers should be used instead. In this paper a method to control the multiple segmented LLSM without position encoder is proposed. The special behaviour during entrance and exit of one moveable unit in an active stator segment is described and the control concept via a master slave relationship is proposed. Experimental results are presented to demonstrate the performance and feasibility of the proposed method.

 

Keywords: long stator linear motor, short block motor, flux observer, encoderless, sensorless, multiple segmented

 

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Experimental Verification of Model Simulation Results of Heating Cycles within the Electric Muffle Furnaces

Lucák, J.

The paper [1] described a mathematical model of the electric muffle furnace. A specific solution of real models has been already solved and presented within this paper. The first one is the muffle heating furnace equipped with a fireproof clay muffle (MODEL I) and thermal insulation of expanded fireproof clay. As the second variant the furnace equipped with a silicon carbide muffle (MODEL II) and with a thermal insulation of fibre ceramic boards of Sibral type is presented. Further the paper presents the results of simulations of the same heating cycles performed using the mathematical model presented in the paper [1] and comparing these results with the progression of the values measured in real furnaces.

Experiment and simulation assessment will be carried out as the final step hereof. Equipment parameters are sources from technical documentations of the manufacturers.

 

Keywords: muffle furnace, thermal process, heating element, furnace lining and mathematical model

 

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Suppression of the Generator Imposition Vibration

Thöndel, E., Vondřich, J.

Generator vibrations occur as a result of unbalanced revolving masses, loading forces and torques, starting and coasting of driving motors and other effects. Suitable mounting of the generator is possible using damping components such as steel springs, pneumatic springs, rubber pads or other damping components. The article describes a numerical calculation of individual deviations of the generator in dependence on time for the given machine parameters and the selected damping components of its mounting using the Matlab program.

 

Keywords: generator, vibration, numerical calculation, Matlab

 

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Validation of Sinus Filter Choke Temperature Model

Kořínek, J.

This article discusses the relationship between the losses of a sinus filter choke. Its influence on the loaded sinus filter temperature field distribution within and on the surface, verification of these performance and temperature relationships. It includes three-dimensional transient finite element analysis (FEA) of the sinus filter choke temperature conditions based on a mathematical description of the conduction, free convection and losses and describing temperature field validation methodology. In addition, there is shown mutual evaluation of the validation measurement and FEA simulation. Finally, there are outlined further options for the future optimisation of the sinus filter choke thermal simulation.

 

Keywords: choke, sinus filter, Ansys, heat transfer, FEA, magnetism, free convection

 

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