干式空心电抗器空间磁场缩比试验与模型简化

Small-scale Experiment and Model Simplification of Space Magnetic Fields Around Air-core Reactors

干式空心电抗器的空间磁场已成为变电站内电磁污染的主要来源,为此,基于缩比试验法对其分布特性给出准确预测。首先,总结了空心电抗器各参数的理论缩比准则,并在保持空间磁场磁感应强度不变的前提下,针对3种典型情况提出相应的修正策略;据此,测量1/2尺寸和1/6尺寸2种缩比系数空心电抗器模型的轴向和径向磁场分布,所得结果与原尺寸模型对应位置的数值基本相符,验证了缩比准则的有效性和缩比试验的等价性;为进一步简化预测过程,提出了由单环、双环和3环载流导体构成的共6种简化缩比模型。试验证明双环简化模型结构1的精确度最高,此时圆环形载流导体与空心电抗器底面的轴向距离为电抗器高度的1/3和2/3。

The space magnetic fields（MFs） generated by dry-type air-core reactors have become the main source of electromagnetic contamination in substations. Thus, we estimated the distribution of the MFs accurately based on scaled experiments. Firstly, we summarized the theoretical scaling rules of the air-core reactors＇ parameters, and proposed the corresponding modification strategies for three typical circumstances on the premise that the magnetic induction intensity around the air-core reactor remained unchanged. Secondly, we measured the MF distributions of a half-size model and a one-sixth-size model in axial and radial directions by the modification strategies, and found that the results were generally in accordance with the corresponding MFs of the original model, verifying the scaling rules, as well as the equivalency of the scaled experimentation. Thirdly, we proposed six simplified models of air-core reactors composed of one-loop, two-loop, and three-loop toroidal conductors to simplify the estimation. Further experiments indicate that, compared with the original model, the two-loop configuration of structure 1 with its two toroidal current-carrying conductors being placed at 1/3 and 2/3 of the reactor height, respectively, is the most accurate.