A rotor of electric motor rotates on the electromagnetic force factor. So, if the rotor made with superconductor materials a change in the performance of the motor achieved. Any electric motor is built with rotor and stator. A Rotor is fixed inside the stator and it is coiled as segments. In regular electric motors that available in market are made with copper conductors (5.96×107 σ). It has resistance at 20 oC with the value 1.68×10−8 ρ, these numbers stand next to silver that is rarely used as conductor coil in rotor.
Copper made rotor provide losses by the form of slip. To overcome slip more copper is used to increase its mass their by increasing the conductivity. To turn this problem toward stability superconductor coiling is preferred in upcoming technologies. This improves the torque and performance of electric motor. Superconductors have negligible resistivity at transition temperatures. Superconductor wires coiled to the rotor in place of regular conductors.
Yttrium barium copper oxide is a product that shows hope for researchers and designers as a feasible superconductor that used in rotor. YBCO can handle four types of mechanisms used for torque generation in electric motors. It has given satisfied results for all four types of synchronous motors also. It is only material right now which have the property of superconductivity at the temperature of 77 K, the highest possible temperature maintained by liquid nitrogen.
Rotor designed changed from coiling type to a cylindrical bulk block. The cylinder itself acts as rotor. However, the disadvantage is the condition to be maintained. Low temperatures only make the superconductor work as per the requirement.
High Temperature Superconductor Element Application in Electric Motor:
HTS stand for high temperature superconductor in advanced high torque electric motors. The demand for efficient motors drives the technology towards superconductor elements. Output power of electrical machines should be increased to meet the futures challenges. For example ships and submarines need high power output and quiet (no sound) propulsion systems. Indeed electrical motors replaced the diesel engines long time ago but the increase in electrical machines efficiency will solve many power saving objectives. One of the technologies has taken the task of improving the motor working efficiency. It is by use of HTS elements. International company like Rockwell Automation and Sumitomo Electric Industries are building and designing these classes of motors. The demo models made are well satisfactory as per Oak Ridge and IHI Corporation.
Automobiles and mechanical driven machines demo models able to work at less power consumption without loss. 200 hp and 1000 hp motors are designed and the prototype models configured and reconfigured to obtain the optimum size and operating temperatures.
Electric vehicle regular motor system space is quite enough for the superconducting system. The performance of the modified vehicle show much improvement in terms of speed, torque and traveling distance with same battery capacity when compared to regular motor system.
YBCO and Bi-2223/Ag are the elements picked from wide variety of HTS elements that were able to work under liquid nitrogen. These two elements generated the out power increase in double the value when compared with conventional motor.