Amadeu Rodrigues

Design of a linear synchronous motor with high temperature superconductor materials in the armature and in the field excitation system

The high diamagnetism observed in high temperature superconducting (HTS) materials lead to applications involving levitation such as the linear synchronous motor (LSM). Certain features taken into account in conventional LSM design cannot be applied in the HTS case, due to these materials characteristics, such as BSCCO stiffness, when used as armature windings. Also other design features, e.g. slot skewing, which reduces the space harmonics of the air gap magnetic flux density, thus influencing motor performance, plays an important role in final cost. These and other aspects such as the thrust force or the effect of motor control through an inverter are examined in this paper, where the analytical and numerical methodologies involved in the design optimisation of a LSM demonstrator with premagnetised YBCO pellets in the field excitation system and BSCCO armature windings are described. Simulation results are also included.

Numerical Design Methodology for an All Superconducting Linear Synchronous Motor

One potential advantage of the application of superconducting materials in electrical machines is the possibility to build lighter and compact devices by removing iron. These machines find applications, e.g., in systems where cryogenics is already available, or in naturally cryogenic environments. The design of motors with high temperature superconductors (HTS) presents issues unconsidered in classical machines, besides considerations on cryogenics, such as HTS brittleness or mechanical restrictions. Moreover, HTS’ electromagnetic properties also degrade due to flux density components, which arise if there is no iron to guide magnetic flux. Several aspects must thus be considered in the design stage, as applications may turn less attractive or even unfeasible. In this paper these issues are detailed, and a numerical methodology for the design of an all superconducting (without iron or conventional conductors) linear synchronous motor is presented.

Disc Motor: Conventional and Superconductor Simulated Results Analysis

Taking into consideration the development and integration of electrical machines with lower dimensions and higher performance, this paper presents the design and development of a three-phase axial flux disc motor, with 50 Hz frequency supply. It is made with two conventional semi-stators and a rotor, which can be implemented with a conventional aluminum disc or a high temperature-superconducting disc. The analysis of the motor characteristics is done with a 2D commercial finite elements package, being the modeling performed as a linear motor. The obtained results allow concluding that the superconductor motor provides a higher force than the conventional one. The conventional disc motor presents an asynchronous behavior, like a conventional induction motor, while the superconductor motor presents both synchronous and asynchronous behaviors.

A new open-loop control method for stepping motor driving

Stepping motors are electromagnetic incremental-motion actuators, which, when energized by a voltage and current input, index in given angular increments. Their inherent positional accuracy makes them suitable for a wide range of motion control and industrial positioning applications, especially when slow and precise movement is required. However, their speed is limited by their torque which diminishes when the applied pulse train becomes too fast. To be more adequate to the necessities of higher speed applications their behavior can be improved through better electrical controller and motor designs.

Preliminary Studies and Test Results of a Superconducting Hysteresis Motor with Multiphase Windings and Variable Number of Magnetic Poles

In this paper a procedure for determining the number of different synchronous speeds that can be obtained from the stator of a drum motor as a function of the number of slots is presented. This preliminary study is foreseen for a hysteresis high-temperature superconducting motor, but the approach is directly applied in conventional motors. The targeted device has multiphase windings, in order to achieve full flexibility in torque-speed space through electronic variation of magnetic poles. Simulations are performed in order to achieve a qualitative understanding of the behaviour of the motor, namely in what concerns to torque and settling times from initial to synchronous speed. A prototype with eighteen slots in the stator and a bulk YBCO rotor is described and built, and experimental values of torque are obtained.

Axial Disc Motor Experimental Analysis Based in Steinmetz Parameters

Nowadays an economical and environment crisis is felt in the world due to the increasing fuel prices and high CO2 emissions. This crisis is mostly due to present the transportation system, which uses internal combustion engines. The development and integration of electrical motors with improved electro mechanical characteristics, using high temperature superconductors, can provide a sustainable future replacing the conventional internal combustion motors.

Message from conference chairs

The purpose of the Conference is to provide the exchange of new ideas and results in the fields of Power Generation, Transmission and Distribution; Power Electronics, Systems and Applications, Electrical Machines and Adjustable Speed Drives, Renewable Energy Sources and Technology, and Education, bringing together researchers and engineers from all over the world, promoting international and national collaboration and attracting more young researchers, from different countries, to this important scientific area. During three days the Conference offers you 6 keynote presentations, 2 invited sessions and 118 lecture presentations. The papers were reviewed according to high quality standards. We would like to express our sincere gratitude to all authors, session chairs, members of the International Program Committee and reviewers. The Conference is technically co-sponsored by the IEEE Industrial Electronics Society and fmancially sponsored by REN and Almada City Hall.