双断口断路器均压电容对换流变励磁涌流的影响

发布时间：2018-11-28 20:54

【摘要】：从换流变压器(简称换流变)空投数据来看,双断口断路器均压电容对空投前的换流变进行的预充电过程影响了励磁涌流的幅值,其影响规律亟需研究。为此,首先从理论上分析了双断口断路器均压电容特性以及变压器在预充电和断路器合闸2个阶段中铁芯磁链的变化,然后运用PSCAD/EMTDC搭建了该直流工程双断口断路器以及换流变模型,并从网侧电压、涌流时间常数和涌流幅值3个角度分析了均压电容对换流变励磁涌流的影响。研究结果表明:换流变空投前网侧电压随均压电容的增大而增大,且电压增大的速率随均压电容的增大而增大;换流变铁芯的时间常数随均压电容的增大而减小,且减小速率随均压电容的增大而减小;换流变励磁涌流的幅值随均压电容和预充电时间的增大而减小。结合上述结果,从削弱励磁涌流幅值的角度,建议结合换流变预充电过程的时间常数,制定操作换流变隔离开关和断路器的间隔时间。
[Abstract]:From the air drop data of converter transformer (abbreviated as rheological exchange), the precharging process of the voltage equalizing capacitance of double break circuit breaker affects the amplitude of excitation inrush current, and its influence law needs to be studied urgently. For this reason, the characteristics of voltage and capacitance of double break circuit breaker and the change of core flux in two stages of precharging and closing of circuit breaker are analyzed theoretically. Then, the double break circuit breaker and rheological model of the DC project are built by using PSCAD/EMTDC, and the influence of voltage equalizing capacitance on rheological inrush current is analyzed from three angles of grid side voltage, inrush time constant and inrush current amplitude. The results show that the voltage of grid side increases with the increase of the average voltage capacitance, and the rate of voltage increase increases with the increase of the average voltage capacitance. The time constant of the rheological core decreases with the increase of the equalizing capacitance, and the decreasing rate decreases with the increase of the equalizing capacitance, and the amplitude of the inrush current of the rheological excitation decreases with the increase of the equalizing capacitance and the precharging time. Based on the above results, from the angle of weakening the amplitude of inrush current of excitation, it is suggested that the interval time between switching rheological isolator and circuit breaker should be determined by combining with the time constant of rheological precharging process.
【作者单位】：中国南方电网有限责任公司超高压输电公司;华南理工大学电力学院;
【基金】：国家自然科学基金(51377059;51677073)~~
【分类号】：TM41;TM561

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