新型小体积电阻型超导故障限流器的研究

Research on a new small-volume resistive superconducting fault current limiter

针对电力系统发展过程中短路故障电流水平持续上升的问题,提出利用基于MgB2的小体积电阻型超导故障限流器限制短路故障电流,并测试其限流性能。结合改进的J-A磁滞模型和绝热一维热传递模型建立了电阻型超导故障限流器的热磁耦合模型和电路方程,动态模拟限流器在发生故障时的工作特性。试验结果显示,该超导故障限流器具有良好的限流作用,其限流率超过49%,失超恢复时间在1.5 s左右,可采用交替联接的方法达到重合闸的要求。结合试验结果充分验证了热磁耦合模型的合理性和精确性,提出在设计上限制超导故障限流器高度以提高MgB2绕组的利用率,为今后电网中MgB2超导故障限流器的研究提供了理论模型基础。

Aiming at the problem that the level of short-circuit fault current continues to rise during the development of power system,it was proposed to use a small-volume resistive superconducting fault current limiter based on MgB2 to limit the short-circuit fault current and test its current limiting performance.Combining the improved J-A hysteresis model and adiabatic one-dimensional heat transfer model,the thermal magnetic coupling model and circuit equations of the resistive superconducting fault current limiter were established to dynamically simulate the operating characteristics of the fault current limiter.The test results showed that the superconducting fault current limiter had good current limiting effect,and its current limiting rate exceeded 49%.The recovery time of overload loss was about 1.5 s,and the method of alternate connection could be used to meet the requirements of reclosing.Combined with the test results,the rationality and accuracy of the thermo magnetic coupling model were fully verified.It was proposed to limit the height of the superconducting fault current limiter in the design to improve the utilization of the MgB2 winding,which provides a theoretical model basis for the future research of the MgB2 superconducting fault current limiter in the power grid.