电磁场数值分析的约束条件

The Constraint Conditions of Numerical Calculation of Electromagnetic Field

系统地分析了各种电磁场数值分析中引入约束条件的必要性。分析说明：电荷守恒定律是静电场计算的约束条件；电流连续性原理是涡流场计算的约束条件。还说明：在恒定磁场中，若用矢量磁位建立数学模型，则在二维场计算时，库仑规范自动满足，但在三维场计算时，必须强加规范选择。还介绍了静电场和涡流场中约束条件的实施方案。

In this paper, the necessity of drawing the constraints into numerical calculation in all kinds of electromagnetic field is analysed systematically. It is pointed out that thelaw of conservation of electric charges is the constraint of calculation of stationary electricfield, the current continua theorem is the constraint of eddy current field. It is also describedthat if the mathematical model of steady magnetic field is established on the magnetic vectorpotential, the Coulomb's norm is satisfied automatically in the calculation of two-demensional field, some specifications must be satisfied in the calculation of three-demensional field.Besides, the ways of implementing constrains in eddy current field and stationary electricfield are described.