非线性时变涡流场—考虑周期性条件的解法

A Method to Solve the Nonlinear Time Dependent Eddy Current Field——Take Account into the Time-Periodic Condition

非线性时变涡流场方程的解,通常需要给定一初值作为迭代求解的开始,而在某些实际情况中,初值(零时刻)是不易确定的,本文提出一种不需要给定初值的,由周期性条件作为约束的有限元方法,并考虑电压源激励,以场路结合的形式对一台单相变压器空载运行过励磁情况下的磁场和电流进行了分析计算,计算与实测结果表明,该方法具有精度高、时间剖分点少等优点。

It is often necessary to be given a initial value as the beginning of iterative solution in solving the nonlinear time dependent eddy current field, but in sometimes, the initial value is difficult to be determined. This paper presents a FEM which is used not for the initial value problems but for the problems which take the periodic time of magnetic characteristics as the restrained condition. Taking account into the external voltage, this method which combined with the circuit equation, is applied to analysis and calculation of a single-phase transformer operating under no-load. Through the comparison of calcul ated and tested results, it demonstrates some eminent advantages of the higher accuracy, the less computing time, etc