有限元电路-磁场耦合的三相变压器直流偏磁仿真

摘要

When HVDC operate on Monopolar ground condition, in the DC by earth and grid to form a loop circulation in transform-er, it caused the transformer core flux increases, magnetic saturation, thus affecting the normal transfer characteristics of transform-er, and DC magnetic bias occurred. Therefore, the calculation of the bias magnetic field caused by DC transmission, need to inte-grated circuits - magnetic field analysis. In this paper, to overcome the general transformer DC bias magnetic field analysis of the defect from the circuit, simulation of three-phase transformer was done based on multi physical field coupling software COMSOL . It detailed bias conditions under different bias voltage of different structure of the three-phase transformer.%直流输电单极—大地运行时，地中直流通过大地和电网构成回路在变压器中流通，使变压器铁心磁通增大，发生磁饱和，从而影响变压器的正常传变特性，发生直流偏磁。因此，计算直流输电引起的直流偏磁磁场，需要综合电路—磁场来分析。本文克服一般变压器直流偏磁磁场分析脱离电路的缺陷，采用多物理场耦合分析软件( COMSOL)进行基于电路—磁场耦合三相变压器直流偏磁仿真，详细进行了不同偏置电压下的不同结构的三相变压器的偏磁情况。