Materials Science Forum Vol. 856

Abstract: The electromagnetic field of the active part of oil-immersed transformers 160kVA and 630kVA has been modelled in the present paper. Finite element method and ANSYS program have been employed for the field modelling. Based on the created model, the field distribution with values of the magnetic flux density has been obtained, as well as the Joule losses have been calculated. Two variants of the model - with and without tank are studied and compared.

Abstract: The magnetic and electrical field in the vicinity of overhead power line for high voltage - 220 kV is investigated. FEM model is created. Simulations of normal and emergency mode of the power line are made. The electrical intensity at idle mode in some areas, close to overhead power line, creates a high voltage level for humans. It can create also disturbances in the electrical equipment and the vehicles. These surges violate electromagnetic compatibility. The magnetic induction at emergency mode – short circuit and lightning strike in the areas around the towers could give a disturbing reaction of humans, animals and sensitive electronic devices. One solution for decreasing of the magnetic flux density to acceptable values is offered.

Abstract: In order to reduce the size and complexity of the driving circuit of the self-bearing motor, this paper proposes a magnetically levitated shaded pole induction motor. The rotor is still supported by magnetic force, but the motor has a very simple structure because magnetic levitation and rotation can be achieved with only one amplifier. The suspension force and rotational torque have been analyzed by FEM magnetic field analysis. A simple experimental setup using the rotor of a commercial shaded pole induction motor was designed and fabricated. Although it did not succeed in levitation control, the rotation control was successful in the situation where perpendicular and horizontal movement of the rotor were restricted.

Abstract: In this paper the strategy of the extraction of an advanced simulation model of interior permanent magnet synchronous machine is suggested in order to be employed by Model Predictive Control schemes. The conventional dq-axis mathematical model is modified in order to include data derived from finite element analysis (FEA). Indirect interaction between FEA and circuit simulation enhances model fidelity embodying the influence of saturation and cross-coupling effects. The proposed method of developing a detailed simulation model opens new prospects on the control of electrical machines.

Abstract: This work presents a new eddy current surface probe that operates with minimal lift-off noise. Probe excitation coil and the two pick-up coils are arranged in perpendicular planes. The conducted numerical analyses indicated that in material surface scanning there are some particular probe positions where the in-phase component of the signal is proportional to the flaw dimensions.

Abstract: Adaptive and interactive mental engagement combined with positive emotional state are requirements for an optimal outcome of the neuro-rehabilitation process for patients with brain damage usually caused by TBI (traumatic brain injury), stroke or brain disease such as cancer, epilepsy, and Alzheimer's disease. We propose a method for automatic pain recognition in video sequences using the landmarks data from Supervised Descent Method and applying Support Vector Machine (SVM) for data classification. This method is suitable for being part of assistive medical system for neuro-rehabilitation of patients with TBI. The experiments with a video dataset with patients with shoulder pain show very good recognition rate (95,7%) for recognizing the painful facial states of the subjects.

Abstract: For robot making high-speed action like human, its actuator needs to be light and powerful. This study developed actuator with permanent magnet arranged in Halbach-array, and examined performance of this actuator by magnetic simulation. In result of experiment, it is proved that actuator exerts a force over 100N when the distance between ring type magnets is 11mm.

Abstract: This paper presents a permanent magnet synchronous serve motor (PMSSM) to replace an induction motor (IM) in the oil hydraulic system in machine tools to drive a pump for supplying the oil. The proposed is designed to meet not only the machine performance, such as higher average torque per volume of magnet usage and the efficiency, and lower torque ripple, but also the energy-saving policy. The motor is optimized using the fuzzy-based Taguchi method. Finally, the proposed motor is installed in the machine tools for measurement, and compared with the tradition machine tools installed with IM.

Abstract: Design optimization of traction motors for light electric vehicles over an operating point is an adequate way of achieving higher overall efficiency under a standard driving scheme of the vehicle. However, this work proves that a direct comparison of similar candidates regarding efficiency values under a predetermined operating point does not yield sufficient information on the economy achieved on a specific driving pattern per candidate. This paper presents a comparative study on three similar surface mounted permanent magnet in-wheel motor configurations. On a first step, these configurations are compared in terms of efficiency and performance over one operating point. On a second step, efficiency maps of the designs under study are utilized to provide a wider picture of their efficiency attributes. On the final step, the three configurations are simulated driving a prototype light electric vehicle in the Urban part of the New European Driving Cycle and the results are discussed.

Abstract: A magnetic gear can transmit a torque and a motion without the contact by the magnetic force. The torque just before the gear idling defines the maximum transmission torque of the magnetic gear. The maximum transmission torque of the magnetic gear is defined by the strength of the magnet and the gap between gears at the stage of design. In this paper, we focus on the adjusting method of the maximum transmission torque at the time of use. The adjusting method is to change the facing length of the magnetic gears by shifting the one of gears in the axial direction. Thus, we reveal the relationship between the torque and the facing length and the relationship between the torque and the gear gap. The limit torque can be assigned on the basis of the obtained relationship.