Analysis Of Influence Of Superconducting Transformer And Air - Core Superconducting Transformer On Relay Protection

This paper is based on theory of superconductivity and theory and technology of relay protection, analyze the effects of HTS transformer and SFCL on protection.At first this paper introduces the creation and development of HTS transformers. Especially,how well countries are doing in researching HTS transformers are described in detail.Based on the fundamental theory of electromagnetism,we can analyse the basic principle of HTS transformers and this leads to advantages and disadvantages.According to the high temperature superconducting tapes properties and the fundamental theory of electromagnetism,we analyse the core magnetic circuit characteristics and structure iron cored of HTS transformers.Secondly, this paper did finite element analysis to calculate HTS transformer parameters. The parameters of calculation included the leakage inductance of HTS transformer and saturated current curve of transformer. Finite element method were used to simulate steady state performance of HTS transformer and proved the basic principles of HTS transformer. So we can built out HTS transformer model according to these parameters based on sinmulink. Using numerical simulation method to calculate fault current and fault voltage of HTS transformer. Analyze the effects of HTS transformer on transformer protection.Starting from the requirement and principle of testing protective devices,this paper mainly research on the effect of HTS transformer on longitudinal differential protection for power transformer. The effect of HTS transformer on zero sequence differential protection for power transformer. The effects of HTS transformer onTransformer over current protection for power transformers.The effect of HTS transformer on composite voltage overcurrent protection for power transformer.The effects of HTS transformer on overcurrent protection with composite start up voltage. The effects of HTS trans-former on Transformer over current protection with low start up voltage. The effects of HTS transformer on instantaneous overcurrent protection. According to the characteristics of protection and the simulationresult, and provided some advisements to improve the transformer protection.At last, the working principle of SFCL is introduced in detail, and we can built out SFCL model based on sinmulink. Analyze the effects of SFCL on earthed neutral power system, and provided some advisements to improve the protection.