研究应用于三相电力系统中新型桥路型高温超导故障限流器.正常工作情况,在电桥上引入直流偏置电流,不出现限流现象.在短路故障情况,整流桥中的直流偏流影响限流效果,将二极管和偏压电源从限流器中退出运行,超导线圈的电感能限制故障电流峰值和稳态值,利用限流电阻与超导线圈串联限流,进一步提高其限流能力.分析了限流器的工作原理和限流特性.仿真结果表明,该限流器有很好的限流和重合闸能力,能显著减少暂态及稳态的故障电流,有效提高系统动态稳定性和电网电能质量.
A novel rectifier type high temperature superconducting fault current limiter for a three-phase power system was developed in the paper. When normal operating,no current limiting mode occurs through the application of DC bias current to the bridge. And at the time of fault,the fault current limiting capability decrease due to the bias DC current,an idea is to put two resistance in series with the superconducting coil for reducing the transient and the steady-state fault current,and turn the switch on and off to disconnect the diode and the bias DC voltage source from the fault current limiter,the inductance of the coil can limit both an increase in a fault current and the steady-state fault current. The operating theory of the new fault current limiter was discussed,and the effect of parameters variety of the fault current limiter was analyzed on limiting fault current. The simulation results show that the device is of good limiting and re-closing capability. The device is of great benefit to improve transient stability and enhance the electrical energy quality of power system.