12-04-2011, 09:31 AM
Presented By,
ADARSH D.N
[attachment=12052]
SUPERCONDUCTING ROTATING MACHINES
Introduction
• The higher current density achievable in many superconducting materials tends to make them smaller compared with non-superconducting machines with the same power density.
• General Electric and Westinghouse independently conducted large superconducting generator design studies during the 1970’s, both approaches were based on Low Temperature Superconductor (LTS wire )
• These machines employed LTS wire made up of a niobium-titanium (NbTi) alloy.
• The complexity and cost of the refrigeration equipment, and the challenging nature of thermal isolation systems that are necessary for allowing LTS materials to operate at an ultra-low 4K, have made rotating machine applications a prohibitive concept.
• American Superconductor Corporation (AMSC) has built and tested a 5000 hp, 1800-RPM motor for industrial market.
• High-temperature superconductors become superconducting at more easily obtainable liquid nitrogen temperatures.
HTS Wire Status
• High temperature superconductor bismuth strontium calcium copper oxide (BSCCO-2223) manufactured commercially by American superconductor (AMSC).
• It is able to carry more than 140-times the electrical current of copper wire of the same cross section, and is robust enough to meet commercial requirements
• However, a newer yttrium barium copper oxide (YBCO) superconductor has been developed .
HTS Machines
• The major components of a rotating machine employing HTS winding
• Only the field winding employs HTS cooled with a cryocooler subsystem to about 35-40K
• The cryocooler modules are located in a stationary frame and a gas, such as helium, is employed to cool components on the rotor.
• Advantages and Disadvantages of superconducting electric machines Compared with a conventional conductor machine.
Advantages:
• Reduced resistive losses but only in the rotor electromagnet.
• Reduced size and weight per power capacity without considering the refrigeration equipment.
Disadvantages:
• The cost, size, weight and complications of the cooling system.
• Motor bearings need to be able to withstand cold or need to be insulated from the cold rotor.
HTS Machine Application In Ship Propulsion
HTS alternating current (AC) synchronous motors provide a very attractive alternative:
• Greater than 98% efficiency across a wide range of ship operating profiles, which can lower fuel consumption and ship operating costs
• Inherently quiet with low weight rotors, no iron teeth.
Market Potential :
“Electric marine propulsion is a market of approximately $250 million that is growing strongly ”.
Benefits Of Using Superconducting Machines
• Lower operating costs
• Less vibration and noise
• Smaller size and weight
• Increased stability
Future Enhancements
• New technology in the form of a litz-wire bar
• This could contribute to an overall performance improvement, especially in efficiency (expected 0.1...0.3%).
• Litz wire made out of many thinner isolated Superconducting wires.
• Litz wire is more concentrated for high frequency applications where the skin effect is more pronounced.
Conclusion
• Today’s motors are fundamentally similar to the electric motors designed over a century ago.
• The motor manufacturing industry has seen only incremental improvement in product design over the past years.
• The advent of high temperature superconductivity has created the opportunity in the technology of motors.
• The cost, size, weight and efficiency benefits of superconducting machines will significantly change the dynamics of the motor manufacturing industry and the motor user market .
ADARSH D.N
[attachment=12052]
SUPERCONDUCTING ROTATING MACHINES
Introduction
• The higher current density achievable in many superconducting materials tends to make them smaller compared with non-superconducting machines with the same power density.
• General Electric and Westinghouse independently conducted large superconducting generator design studies during the 1970’s, both approaches were based on Low Temperature Superconductor (LTS wire )
• These machines employed LTS wire made up of a niobium-titanium (NbTi) alloy.
• The complexity and cost of the refrigeration equipment, and the challenging nature of thermal isolation systems that are necessary for allowing LTS materials to operate at an ultra-low 4K, have made rotating machine applications a prohibitive concept.
• American Superconductor Corporation (AMSC) has built and tested a 5000 hp, 1800-RPM motor for industrial market.
• High-temperature superconductors become superconducting at more easily obtainable liquid nitrogen temperatures.
HTS Wire Status
• High temperature superconductor bismuth strontium calcium copper oxide (BSCCO-2223) manufactured commercially by American superconductor (AMSC).
• It is able to carry more than 140-times the electrical current of copper wire of the same cross section, and is robust enough to meet commercial requirements
• However, a newer yttrium barium copper oxide (YBCO) superconductor has been developed .
HTS Machines
• The major components of a rotating machine employing HTS winding
• Only the field winding employs HTS cooled with a cryocooler subsystem to about 35-40K
• The cryocooler modules are located in a stationary frame and a gas, such as helium, is employed to cool components on the rotor.
• Advantages and Disadvantages of superconducting electric machines Compared with a conventional conductor machine.
Advantages:
• Reduced resistive losses but only in the rotor electromagnet.
• Reduced size and weight per power capacity without considering the refrigeration equipment.
Disadvantages:
• The cost, size, weight and complications of the cooling system.
• Motor bearings need to be able to withstand cold or need to be insulated from the cold rotor.
HTS Machine Application In Ship Propulsion
HTS alternating current (AC) synchronous motors provide a very attractive alternative:
• Greater than 98% efficiency across a wide range of ship operating profiles, which can lower fuel consumption and ship operating costs
• Inherently quiet with low weight rotors, no iron teeth.
Market Potential :
“Electric marine propulsion is a market of approximately $250 million that is growing strongly ”.
Benefits Of Using Superconducting Machines
• Lower operating costs
• Less vibration and noise
• Smaller size and weight
• Increased stability
Future Enhancements
• New technology in the form of a litz-wire bar
• This could contribute to an overall performance improvement, especially in efficiency (expected 0.1...0.3%).
• Litz wire made out of many thinner isolated Superconducting wires.
• Litz wire is more concentrated for high frequency applications where the skin effect is more pronounced.
Conclusion
• Today’s motors are fundamentally similar to the electric motors designed over a century ago.
• The motor manufacturing industry has seen only incremental improvement in product design over the past years.
• The advent of high temperature superconductivity has created the opportunity in the technology of motors.
• The cost, size, weight and efficiency benefits of superconducting machines will significantly change the dynamics of the motor manufacturing industry and the motor user market .
