雷电冲击电压下空心电抗器电压分布特性研究

Study on voltage distribution characteristics of air-coredreactor under lightning impulse voltage

针对目前空心电抗器雷击过电压下内部绕组电压分布无法定量计算的问题,建立一种适用于空心电抗器结构的高频阻抗网络等效分析模型。根据基尔霍夫基本定律,提出雷击电压下暂态、稳态电压分布的计算方法,能够计算电抗器内雷击电压下的电压分布。以实际并联空心电抗为例,对计算得到雷击电压下的电压分布与实际测试的电压分布进行分析。根据计算结果发现,内外包封中1-2匝线圈的承担电压及不均匀系数均较大,主要与内外侧对地电压引起的电压钳位有关。

Aiming at the current problem that the voltage distribution in the internal windings of air-cored reactors under lightning overvoltage cannot be calculated quantitatively,a high-frequency impedance network equivalent analysis model suitable for air-cored reactor structure is established.According to Kirchhoff's basic law,a calculation method for transient and steady state voltage distribution under lightning overvoltage is proposed,which can calculate the voltage distribution within the reactor under lightning overvoltage.Taking an actual parallel air-cored reactor as an example,the voltage distribution under lightning overvoltage calculated and the actual measured voltage distribution are analyzed.Based on the calculation results,it is found that the voltage borne by 1-2 turns of coils in the inner and outer envelopes and the non-uniformity coefficient are both large,which is mainly related to the voltage clamp caused by the inner and outer side voltage to ground.