Superconducting Synchronous Generator Research Articles

Construction of a 100 kVA High Temperature Superconducting Synchronous Generator

This paper reports on the design and construction of the 100 kVA High Temperature Superconducting generator which is successfully built at the University of Southampton. The generator is a 2-pole synchronous machine with a conventional 3-phase stator and a HTS rotor which is constructed from stacks of 9 wt% Ni steel plates. The rotor winding is made of ten single vacuum impregnated pancake coils connected in series and operated in the temperature range 73-77 K. The relatively high operating temperatures are made possible by the use of metallic core as well as flux diverters between the coils. These coils have been successfully manufactured and tested over several cooling cycles. These provide the necessary mechanical support whilst minimizing the heat intake to the rotor core. The coils generate an air gap flux density of about 0.6 T at 77 K, while producing a perpendicular magnetic field of only 0.038 T to board face of the superconducting tape. Furthermore, the design and construction of two novel fiberglass torque tubes is also presented.

Applying Continuum Design Sensitivity Analysis Combined With Standard EM Software to Shape Optimization in Magnetostatic Problems

This paper explores the physical meaning of pseudosources of an adjoint system in a continuum design sensitivity analysis (CDSA) when applied to shape optimization in magnetostatics. An efficient and practical way to compute the required gradient information with standard electromagnetic (EM) software packages is suggested. Based on this novel methodology, designers will be able to deal with practical design optimization of electro-mechanical devices using existing analysis tools without the need to access the complicated code of the EM software. The applicability of the proposed methodology is demonstrated by optimizing the salient pole face shape of a high-temperature superconducting synchronous generator.

An approach to the shape optimum design of superconducting synchronous generator

A superconducting synchronous generator (SSG) is characterized by an air-cored machine with its rotor iron and stator iron teeth removed. For this reason, in the case of the shape optimum design of SSG, other design variables different from an iron-cored machine should be considered, which will lead to substantial improvement on the performance. The major design variables that are considered by using 3D finite element method (FEM) in this paper are: (1) field coil width; (2) axial length of magnetic shield; and (3) armature winding method. The end-ring of the armature winding is considered in the calculation of EMF. When it comes to field coil width, as the field coil width enlarges, its effective field increases but the maximum field on the superconductor decreases. This determines the critical current density. This study presents an effective field coil width, axial length of magnetic shield, and armature winding method, and also the analysis is verified by experimental results.

Measurement and analysis of 70 MW superconducting generator constants

The constants of a superconducting synchronous generator (SC-generator) were measured to prove its design method and electromagnetic analysis. This paper describes the test results related to the measurements of synchronous machine constants, and the comparison between the test results and the values which are calculated by a 3 dimensional finite element method (3D-FEM) for the electromagnetic analysis of SC-generator. The test items compared with the analysis are no load saturation curve of armature voltage at rated speed, armature current of steady state short circuit, air gap magnetic flux to add the armature current and synchronous reactance (Xd). The constants for the transient state of SC-generator were measured by three-phase sudden short circuit current. The effect to improve the electric power system stability is analyzed by decreasing Xd of SC-generator and by comparing the stability of a conventional generator for the same power system disturbances.

Electromagnetic behaviors of a superconducting synchronous generator under steady-state and sudden-and permanent-short circuits.

Electromagnetic behaviors of a superconducting synchronous generator under steady-state and sudden-and permanent-short circuits.

Dynamics of experienced magnetic fields and electromagnetic forces on windings in a superconducting synchronous generator.

Dynamics of experienced magnetic fields and electromagnetic forces on windings in a superconducting synchronous generator.

Overview of the development of superconducting synchronous generators

Superconducting synchronous generators are being developed world wide. Early results established the feasibility of these machines and showed that the best configuration is a rotating superconducting field inside a normally conducting armature in the stator. Extensive analytical development is providing a sound basis for the design of superconducting AC machines. Recent experimental results have demonstrated power density improvements over that of conventional generators. The designs developed by different groups are significantly different in the following areas: Rotor shielding and rotor structure; field coil support and construction; superconductor design; helium system design; and armature configuration. The development strategies of the groups have different emphases on basic engineering, development of components, and construction of prototypes. The major deficiencies of the programs are no full-load or full-fault testing.

超電導同期発電機の負荷時の磁束分布の計算

超電導同期発電機の負荷時の磁束分布の計算

Equivalent circuit modeling of a superconducting synchronous generator with double electromagnetic shields (Part I. Development of theoretical equations)

Equivalent circuit modeling of a superconducting synchronous generator with double electromagnetic shields (Part I. Development of theoretical equations)

Equivalent circuit modeling of a superconducting synchronous generator with double electromagnetic shields (Part II. Equivalent circuit model and estimation of its constants for design examples)

Equivalent circuit modeling of a superconducting synchronous generator with double electromagnetic shields (Part II. Equivalent circuit model and estimation of its constants for design examples)

超電導同期発電機の等価回路モデリング

超電導同期発電機の等価回路モデリング

Equivalent circuit modeling of a superconducting synchronous generator

A method is proposed for deriving the equivalent circuit of a superconducting synchronous generator of coreless structure. In deriving the equivalent circuit, account was taken of the nonlinearity of the electromagnetic shield. Linear constants of this equivalent circuit can be calculated directly using design data, and nonlinear constants are determined using the linear constants thus determined. A method is also proposed to linearize the nonlinear equivalent circuit. The equivalent operational impedances obtained by this method make it possible to analyze the behavior of a superconducting generator in the same way as conventional synchronous generators are analyzed.