The Study On HTS Cable Simulation Model Based On PSCAD

HTS cable is an effective way to solve the severe situation of the transmission and. distribution of power system. HTS cable runs under low temperature environment. The system will quench when it is disturbed by over-current, cooling device failure, cable faults and other body disturbances. Then the temperature of HTS cable will rise rapidly because of a lot of Joule heat generated within the cable, which affects the whole cooling device and safe operation of the system. Therefore, the thermal analysis of high temperature superconducting cable under fault current is important for safe operation of the system. And it is also the base of the studies of quench detection and protection.From the structure of high temperature superconducting cable, this paper summarizes the Quench characteristics, electromagnetic theory and electromagnetic parameters of high temperature superconducting cable. And it analyses the thermal properties of high temperature superconducting cable. Then the paper proposes a mathematical model of temperature of HTS cable under transient and uses Matlab and PSCAD software for the simulation analysis.First, the paper summarizes the material properties of high temperature superconducting cable and analyses the nonlinear coupling relationship of the various parameters such as critical current, volumetric specific heat capacity, electrical resistivity, thermal conductivity, and the value of n of strip. On the base of the laws of thermodynamics, the paper proposes radial temperature mathematical model of HTS cable under fault state.Then, the paper simulates220kV HTS cable model by Matlab software, the main function of the temperature distribution analysis of changes in the resistance and the cable fault condition of high temperature superconducting cable with temperature. It analyses the temperature distribution and the changes of cable resistance with temperature of high temperature superconducting cable under fault state.Finally, this paper programs the module assembly of high temperature superconducting cable using Fortran language in PSCAD, and establishes the power system simulation model with HTS cable module assembly. It analyses the current distribution of high temperature superconducting cable under transient operation. Then it gets temperature changes with time of HTS cable and gets resistance changes with time of HTS cable under different fault conditions. It also analyses the amplitude relationship between the superconducting layer and the shield layer of HTS cable in the case of a three-phase short-circuit current. It is the foundation of quench detection and quench protection of HTS cable.The two simulation results show that the temperature of shield layer and superconducting layer increases the moment when the system phase short circuit occurs, but it decreases with failure to lift. And resistance of superconducting layer and shield layer will increase as the temperature. Therefore, it verifies the feasibility of the cable temperature mathematical model proposed in this paper.