基于广义谐振理论的输电线路无源干扰谐振频率求解

A Resonance Frequency Solution to Passive Interference for Power Transmission Lines Using Generalized Resonance

IEEE标准难以完全预测中波频段输电线路的无源干扰谐振频率,同时现有方法计算量过大,为解决此问题,提出基于广义谐振理论的输电线路无源干扰谐振频率求解方法。首先,结合坡印廷定理,从电磁能量平衡的角度出发,将包含输电线路及无线电台站的封闭面等效为广义封闭系统;然后,根据复频率理论,推导输电线路与无线电台站所构成电磁系统的谐振频率与品质因数Q值之间的关系表达式;最后,对观测点的散射场强进行采样,采用模型参数估计的方法求解反映散射场强与频率映射关系的系统函数。以IEEE计算输电线路无源干扰的模型为算例,通过仿真计算验证所提方法可将无源干扰谐振频率预测范围扩展至3 MHz。此外,与矩量法相比,当采样点选择适当时,最大谐振频率偏差可控制在3%以内。

In order to solve the problem that the passive interference resonance for power transmission lines at medium band frequency can not be fully predicted by using IEEE standard and the existing methods require large calculation quantity,this paper proposes a method for the resonance frequency of passive interference for power transmission lines considering generalized resonance theory.Firstly,based on Poynting theorem,the closed surface including power transmission lines and radio stations is equivalent to a generalized closed system from the perspective of electromagnetic energy balance.Then,according to the complex frequency theory,the relationship expression between the resonant frequency and the Q value of the electromagnetic system consisting of power transmission lines and radio stations is derived.Finally,the scattering field strength samples at observation points are taken,and the system function reflecting the mapping relationship between scattering field strength and frequency is solved by model parameter estimation method.Taking the model for calculating the passive interference of transmission lines as an example on IEEE systems,both rationality and effectiveness of the proposed method are validated by simulation results.The proposed approach can extend the prediction resonance frequency range of passive interference up to 3 MHz.In addition,compared with the moment method,when the sampling points are properly selected,the maximum resonance frequency deviation is within 3%.