Lightning Electromagnetic Transient Calculation Based On The Method Of Harmonic Balance

When lightning strikes the transmission line, it often causes the tripping accident. In order to limit the lightning overvoltage, zinc oxide surge arrester is widely used because of its good nonlinear characteristics. When the nonlinear circuit is analyzed, most of the nonlinear elements are expressed in time domain. In order to avoid the simple analysis of nonlinear circuits in time domain or frequency domain, the proposed method of harmonic balance method is of great significance.Compared with the time domain method of the transient network analysis, due to the linear network containing a large quantity and complex transmission line system and centralized parameters(linear element) element, but nonlinear elements is relatively small, such as the use of frequency domain method is easy to set up a linear system of port model, so as to reduce the difficult y of the complexity and solution of the linear network modeling. Therefore, the harmonic balance method achieve nonlinear components in the frequency domain to solve the transient analysis has the advantages of good. In this paper, the overvoltage of the surge arrester is studied by using the method of harmonic balance. The model of lightning current, surge arrester and transmission line is established, and the equivalent circuit of the transmission line is adopted. In the study of the single conductor transmission line, the voltage waveform of the surge arrester is calculated The results show that the calculation results are correct and effective. At last, according to the characteristics of the electromagnetic coupling between the line and the line, the ha rmonic balance method is applied to the multi-conductor transmission line.