基于Jiles-Atherton磁滞理论三相三柱变压器直流偏磁的电磁混合模型

Electromagnetic Hybrid Model for Three-phase Three-leg Transformer DC Bias Based on Jiles-Atherton Hysteresis Theory

直流输电系统单极运行情况下,直流通过变压器接地中性点,构成交流系统变压器的直流偏磁,准确获得变压器铁心的磁性能并建立变压器暂态模型是分析偏磁问题的关键。介绍了基于反映物理机制的Jiles-Atherton磁滞模型模拟铁心磁化性能、以三相三柱式变压器铁心和绕组的空间结构为基础、建立的变压器电磁混合模型,研究了偏磁条件下励磁电流及其谐波的规律特性。并与实测数据进行对比分析,结果表明:实验结果和计算结果吻合,本文提出的变压器电磁混合模型具有一定的可行性,提高了磁路耦合变压器模型的精度。

The DC current flows into earth as HVDC system runs in monopole, then the DC current flows into the AC transmission system through the neutral point of transformer, leading to the transformer DC bias. The key to DC bias analysis is to obtain accurately magnetic properties of transformer core and to establish the transient model for the transformer. For the transformer electromagnetic hybrid model, the Jiles-Atherton hysteresis model based on physical mechanism is adopted to simulate core magnetization performance; the Spatial structure of the core and coil of threephase three-leg transformer is taken as the basis. The law of the exciting current and its harmonic under the condition of DC bias has been studied. Compared with the measured data, consequently, the computation results coincide well with the experiment results. This proposed electromagnetic hybrid model for transformer demonstrates certain feasibility, and improves the accuracy of the model for the magnetic circuit coupling transformer.