In this paper, we present a new approach to protection of double-circuit transmission lines using modal transformation. The current differential principle is applied in the modal domain, and the relay characteristics are plotted in the alpha plane for numerical differential protection applications. Synchronized voltages and currents from both the ends are transformed to modal values. The transmission lines are modeled as equivalent $$\pi $$ π model in modal domain, and line charging current is compensated. Electromagnetic transient program EMTP-ATP is used to simulate the double-circuit transmission systems, and the algorithm is implemented in MATLAB. The extensive case studies demonstrate the utility and the superiority of the proposed current differential scheme.

中文翻译：

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模态双回输电线路电流差动保护

在本文中，我们提出了一种使用模态变换保护双回输电线路的新方法。电流差动原理应用于模态域，在数值差动保护应用的 alpha 平面中绘制了继电器特性。来自两端的同步电压和电流被转换为模态值。传输线在模态域中被建模为等效的 $$\pi $$ π 模型，并补偿了线路充电电流。采用电磁暂态程序EMTP-ATP对双回路输电系统进行仿真，算法在MATLAB中实现。广泛的案例研究证明了所提出的当前差分方案的实用性和优越性。