The Design And Optimization For High Temperature Superconducting Transformer

As a key part of the power transmission, the improvement of transformer efficiency can greatly save electric energy. Traditional transformer has reached a very high efficiency. So, new materials is badly in need to further improve the efficiency of transformer. Therefore, due to high temperature superconducting material’s characteristics of the zero resistance and high current density, it is applied to the transformer. In this paper, on the basis of summarizing the development of high temperature superconducting(HTS) transformer, the two different kinds of HTS transformers were designed, including the parameters of the iron core, windings and cryostat. The magnetic fields of the designed two transformers were also analyzed. In the end, the magnetic fields of windings were optimized including the optimization for the magnetic fields of the sides and ends of windings according to the results of the magnetic fields analysis. In this paper, the main work was as follows:1. Briefly introduced the research background, advantage and research status of HTS transformer at home and abroad.2. Analyzed the basic principle and components of HTS transformer including iron core, windings, cryostat and refrigerator.3. Designed and analyzed two HTS transformers with different capacities and types: 10 kVA single-phase HTS transformer, and 1 MVA three-phase HTS transformer.Analyzed and verified magnetic fields of the designed transformers.4. Researched the optimization for magnetic fields of the sides of the windings.There were two main ways that were analyzed: One was changing air gap including changing the length and number of air gap. Another is optimizing tape. Replaced parallel tapes with superconducting composite conductor. Analyzed two superconducting composite conductors Roebel cable and TSTC cable. Roebel cable could make the current and magnetic field distributions more uniform because of periodic transposition. TSTC cable made several superconducting tapes twisted stacked.This composite conductor could transfer large current.5. Researched the optimization for magnetic field of the ends of the windings.Mainly analyzed effect of flux diverter on the magnetic fields of the ends including the relative magnetic permeability of flux diverter, the distance between flux diverter andthe end of windings and the thickness of flux diverter. And proposed using the unbalanced degree of the magnetic field to choose these parameters in the end.