The wind turbine market is growing rapidly, and there has also been a trend toward ever increasing turbine rating. Most turbines to date has used geared high speed generators, but a history of gearbox reliability problems have turned many turbine manufacturers towards direct drive generators, which are very low speed, high torque, and therefore very large. Superconducting machines offer the possibility of much more compact machines, but the high cost of HTS wire to date has prevented their application to a cost sensitive market such as wind energy. A new generation of low cost HTS wire is being developed which will allow HTS machines to compete in such a market. Consequently, Converteam are undertaking a project to design a full size direct drive HTS generator, including the manufacture and test of a scaled model generator. The 1 st stage conceptual design phase, including economic assessment, has completed which has identified solutions to the anticipated challenges and risk.

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The ALSTOM Advanced Induction Motor has evolved over a period of around 15 years, during which time function and performance have steadily improved. In the electric warship, compactness of the propulsion motor is important, but so also must be reliability, structureborne noise signature, and shock withstand ability. This has been achieved in the Advanced Induction Motor through optimization of the electromagnetic design and material properties to suit the operating conditions of a propulsion motor. One of the advantages of an induction motor is its mechanical simplicity. This leads to not only to inherent reliability, but also to simpler design for shock requirements. Through careful motor and system design, it has been possible reduce structureborne noise signatures to levels that permit hard mounting of the motor to the hull of a surface combatant. The paper reviews the evolution of the Advanced Induction Motor from industrial induction motors, and the considerations necessary to achieve low noise signature and shock requirements.

There are plans for a large expansion of offshore wind energy, particularly in Northern Europe where there is limited space for onshore turbines. One means to reduce the cost of offshore wind energy is to build wind farms with fewer larger turbines, reducing the number of costly offshore foundations. The emerging next generation of HTS technology, which offers the prospect of low cost high volume HTS wire production, can be used to build compact and lightweight generators at high rating and torque. These new generators will become the enabler for very large, direct drive wind turbines in the 10 MW class. Direct drive turbines also offer an improvement in reliability and effi ciency by removing the gearbox, which has been a troublesome component in many offshore wind farm projects, and replacing it with a much simpler mechanical system that is not sensitive to the misalignment or to fl uctuations in the shaft torque. Reliability is particularly important in offshore turbines where access is diffi cult and expensive and often prevented by weather conditions. Converteam UK Ltd. are in the fi nal stages of a project to design a direct drive HTS generator for this class of turbines, and to build and test a scaled prototype. Following on from this project will be the manufacture of a full size prototype and its demonstration on a 10 MW turbine. An economic analysis during earlier stages of the project calculated a reduction in the cost of energy of 17% from a 500 MW offshore wind farm by the use of this class of HTS direct drive turbines compared with the baseline case of 4 MW conventional DFIG turbines. This analysis did not include any additional cost reduction due to improved reliability and availability. 1 I ntroduction The wind turbine market is large and rapidly growing; while at the same time there has been a trend towards larger and larger turbines. Larger turbines are attractive

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