电力电缆工频磁场计算方法探讨

Discussion on Calculation Method of Power Frequency Magnetic Field of Power Cable

提出了一种电力电缆工频磁场的等效计算方法。根据安培环路定则确定每相电缆对测量点的磁场贡献,利用局部坐标和叠加定理对每相电流的磁场贡献进行矢量相加,建立了电缆外任意一点的磁感应强度与三相电流之间的物理数学模型,给出了用于计算电缆外任意一点磁场的解析表达式。电磁场有限元仿真和等效模型计算的结果表明,建立的等效模型具有满足需求的准确性,对电力电缆的磁场计算具有指导价值。

An equivalent calculation method for power cable power frequency magnetic field is proposed. The magnetic field contribution of each phase cable to the measuring point is determined according to the ampere loop rule. Using the local coordinates and superposition theorem, the magnetic field contribution of each phase current is vector added. The physical and mathematical model between the magnetic induction intensity at any point outside the cable and the three-phase current is established, and the analytical expression for calculating the magnetic field at any point outside the cable is given. The results of electromagnetic field finite element simulation and equivalent model calculation show that the established equivalent model has the accuracy to meet the demand, and has the guiding value for the magnetic field calculation of power cable.