The Study Of The Character Of Short Time Of 220kV HTS Cable And Its Quench Protection

With the development of the national economy the demand of the electric is developing fast.The power-supply system has faced the decreased of the transmission corridor.The high temperature superconducting power technology is introduced to solve the problem.The high temperature superconducting cable is put into use widely.The transient characteristics of the high temperature superconducting cable and the superlose testing technique need to study once the electric system is getting into failure.This dissertation is wrote based on the experience at home and abroad.And I have designed 1:1 high temperature superconducting cables entity model,the Cable conductor layers and shielding use the YBCO high temperature superconducting material.The conductor layers and shielding layer insulation used PPLP insulating paper.I used the inside cooling method.I use the liquid nitrogen flow throw the copper circulation within the framework to get out the heat.I got the high temperature superconducting U-I curve and the cable transient impedance characteristics through putting the current surge on the high temperature superconducting cable.This dissertation has analysis the nonlinear coupling relationship between the factors that can impact high temperature superconducting cable resistance changes.A mathematical model is rebuilt.This model include the cable is transient temperature distribution.The electromagnetic transient simulation software is used to build the model.This model has considered the critical current superconductor N value curve copper volume specific heat superconducting strip volume specific heat let heat conduction coefficient cable is temperature distribution,etc.These factor is based on the temperature.The simulation analysis the high temperature superconducting cable's various kinds of fault of all the factors under the current distribution characteristics curve of high temperature superconducting cables impedance characteristics on the single-phase grounding system occurring three-wire grounding.In this dissertation,the amplitude difference detection and phase difference value detection is analysised.The simulation of the power system to produce all sorts of short circuit faults verified the feasibility of the two methods.The advantage of two methods is fast detection and save the league differential protection use of communication equipment and light channel.The biggest advantage is that caused by the fault fault phases in the shield is lost can be detected.