交直流混杂模式下变压器励磁电流谐波与箱体损耗映射研究

Research on Maping from Excitation Current Harmonic to Tank Loss for AC-DC Hybrid Operation of Transformer

电力变压器遭受直流扰动时励磁电流发生畸变,谐波含量显著增加,易导致金属构件局部损耗增大和过热。针对此问题,该文研究了变压器励磁电流谐波与箱体损耗的映射关系。基于电磁耦合原理构建交直流混杂模式下的变压器状态方程,利用端口电气信息研究励磁电流辨识方法,对励磁电流进行谐波分析,利用谐波电流有效值表征励磁饱和状态,通过仿真计算与动模实验深入分析变压器的电磁特性,并验证该方法的正确性。在此基础上进一步研究变压器在不同运行方式、直流水平及负载率时箱体的漏磁和涡流损耗分布,并总结其变化规律,通过拟合的方法构建励磁电流谐波与箱体损耗的映射关系数学模型,为交直流混杂模式下变压器构件损耗计算提供了可行方法。

Excitation current distorts and harmonic components are increasing significantly when the power transformer is impacted by DC disturbance, which causes partial loss and temperature rising in metal components, so the mapping relationship between excitation current harmonic and tank loss of transformer is studied in this paper. The state equation of transformer is constructed based on electromagnetic coupling principle in AC-DC hybrid mode, then the excitation current identification method is studied based on port electrical information. Harmonic analysis of excitation current is used to present the excitation saturation state by harmonic current RMS, furthermore, the electromagnetic characteristics of transformer are analyzed through calculation and dynamic simulation experiment, verifying the validity of this method. On this base, the leakage flux and eddy current loss in tank is simulated under different operation situation. Summarizing the variation rule of abnormal feature, the mathematical model of mapping relationship between excitation current harmonics and tank loss is fitted, which provides a feasible way for calculation of components loss in AC-DC hybrid operation.