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We give an overview of wind and ocean power generation methods. Wind generation is now an established large global business while ocean generation is still in the prototype stage of development. The most important parameter for commercial acceptance of these technologies is the levelized cost of electricity produced by them. We discuss areas necessary for further cost improvement of wind generation. We further discuss the types of electrical generators used in these applications. [ABSTRACT FROM PUBLISHER]

General Electric, under contract with the Air Force Research Labs (AFRL), has successfully developed and tested a high speed, multimegawatt superconducting generator. The generator was built to demonstrate high temperature superconducting (HTS) generator technology for application in a high power density Multimegawatt Electric Power System (MEPS) for the Air Force. The demonstration tested the generator under load conditions up to 1.3 MW at over 10,000 rpm. The new MEPS generator achieved 97% efficiency including cryocooler losses. All test results indicate that the generator has a significant margin over the test points and that its performance is consistent with program specifications. This demonstration is the first successful full-load test of a superconducting generator for the Air Force. In this paper we describe the development of the generator and present some key test results used to validate the design. Extrapolation to a higher power density generator is also discussed. [ABSTRACT FROM AUTHOR]

A small high-temperature superconductor (HTS) coil was designed and tested at the General Electric Global Research Center to evaluate the overcurrent capability for the HTS generator rotor. The superconducting rotor coil is a layer-wound racetrack coil using the BSCCO 2223 conductor. Overcurrent simulation tests have been done to simulate the fault operation condition for the generator based on previous analysis work. The obtained data are used to evaluate the performance of the HTS material in generator applications. [ABSTRACT FROM AUTHOR]

When a synchronous generator connected to the power grid experiences a fault, it is required to stay on line, ride through the fault, and be able to carry full rated field current when the fault is cleared. The peak current during these events could be 2 times higher than the normal operating current. This may cause an HTS rotor coil to go into normal state and generate Joule heating. If the fault event is short enough and the heat dumped can be carried away by the cooling system, the coil may recover to the superconducting state at the end of the fault. Otherwise, the coil may thermally run away, or ‘quench’. To investigate the quench behavior of the HTS rotor coil of the 100 MVA generator at GE Global Research Center, a 1.5 MVA prototype coil was developed and tested to quench under different conditions. The experiment design, set up, tests and test results are presented in this paper. [ABSTRACT FROM AUTHOR]

High-temperature superconducting (HTS) coils are generally stable against transient thermal disturbances. Protection against spontaneous quenches is not a main design issue for an HTS coil. However, HTS coils used in many electric devices such as motors, generators, transformers, and current limiters will operate under over-current fault conditions, which may result in a coil quench and thermal runaway. Those electric devices should be able to ride through some grid fault conditions and remain functional. This requires a certain over-current capability of the HTS coils. This paper discusses the over-current requirements from grid faults and the thermal transient responses of a BSCCO coil. It presents the analysis results of the coil subjected to over-current pulses at different operating conditions. The study also investigates the thermal runaway current and its relationship with the over-current pulse. [ABSTRACT FROM AUTHOR]

HTS wires, which may be used in many devices such as magnets and rotating machines, may be subjected to mechanical strains from electromagnetic, thermal and centripetal forces. In some applications these strains will be repeated several thousand times during the lifetime of the device. We have measured critical current degradation due to repeated strain cycles for both compressive and tensile strains. Results for BSCCO-2223 HTS conductor samples are presented for strain values upto 0.5% and cycle numbers up to and beyond 104. [ABSTRACT FROM AUTHOR]