US and French scientists jointly design and test new superconducting motors

Reported on May 24, 2007, the electric motor field is currently entering a new era. All the motors you see today that apply to washing machines, toys, and fans use the basic principles of motors that were invented 50 years ago. However, as superconducting lines replace conventional copper coils, electric motors have become more compact, more energy efficient, and less expensive, especially in large industrial applications.

Recently, Al Hadjay Alam, a scientist from the University of Nancy, France, and the Advanced Power System Center in Tallahassee, Florida, and his colleagues have designed and tested a non-traditional technology. Superconducting rotating electrical machine. Their research results were published in the Journal of Electrical and Electronics Engineers, "Superconducting Applications", which provides a better opportunity for the development of electric motors.

Aram, who currently works with the University of Khemis Miliana in Algeria, said: "This research has two goals. The first goal is to demonstrate the feasibility of a motor based on magnetic flux strength, and the second goal is to demonstrate that superconductors can Greatly improve the performance of the motor."

Compared to high-temperature-based motors designed in previous years, the electric motor developed by Aram and colleagues is a low-temperature, electric eight-pole motor that is also equipped with a fixed superconducting inductor. Unlike copper coils, the neodymium-titanium (NbTi) induction coils in the new design have no resistance, which is one of the biggest advantages of superconductors.

These currents create a magnetic field when two neodymium-titanium induction coils are passed by current in opposite directions. Located between two coils, four superconducting bulk metal plates for shaping and distributing magnetic energy lines (it is made of YBaCuO, or beryllium copper), this magnetic field will then be based on magnetic separation. An interactive electromagnetic field is generated. A rotating armature wrapped with copper wire converts electrical energy into mechanical energy and ultimately transforms it into a practical application.

In this design, the temperature of the entire inductor is cooled to 4.2 (Kelvin) by using liquid helium to maintain the zero resistance characteristic in the coil. (Scientists have explained that high-temperature lines can also work in this layout.) For all superconducting motors, superconducting lines can carry a larger amount of current than copper wires. Therefore, a superconducting motor can create a more powerful magnetic field in a smaller space than a conventional motor.

Aram said: "For most superconducting motors, the structure is traditional, the magnetic flux is radial, [however] for the motor we developed, the magnetic flux of the inductor is axial."

In order to test the performance of this motor, scientists first calculated its magnetic trapezoidal potential, which can explain the force generated by a magnetic field in a certain area. Then they decide the magnetic flux density, which is the amount of magnetism in that area. As scientists have explained, there is a maximum flux density between two bulk metal plates, and the minimum flux density is present after the metal plate. The large difference in flux density can produce a more powerful A magnetic field optimizes the performance of the motor. The team demonstrated the performance of the 118.8 volt motor on an experimental basis. They further calculated a theoretical voltage of 172.5 volts and explained that the difference between them should be attributed to an uncertainty that the magnetic fields around the bulk metal plate have different maximum and minimum values, they are Direct measurement is not possible. Improving the difference in magnetic flux density will hopefully increase the voltage of the motor.

Aram said: "As we have argued in another research article, the demonstration is underway. Compared to conventional motors, this structure and several superconducting wires and 20mW power generation The motor can reduce the amount of induction by 20%-50%."

In the near future, the research team plans to use the same structure to design and manufacture a 100kW superconducting motor. "The biggest advantage of these motors is their high power density and high torque density, and less vibration than conventional motors," he said. He added: "Generally, I think marine propulsion and electric traction. May benefit a lot from these motors." (Yalong)

The original English link can be found at: http://

Legend: Scientist's experimental setup: (1) fixed cryostat; (2) induction motor; (3) strap; (4) taxi, contact - (a) brush, (b) ring.

Others Stamping and Bending

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