The availability of zero-sequence current, under normal circumstances, determines the accuracy of the operation of a distance relay which is connected to a mutually coupled parallel line. When this is not available, the system adopts a different compensation factor which if, not properly calculated introduces errors in the relay operation. The proposed adaptive protection scheme, described in this paper, consists of three modular artificial neural networks model (ANN). This is developed using the feed-forward nonlinear backpropagation Levenberg–Marquardt algorithm that determines the actual status of the mutually coupled lines. The remote terminal units connected to the current and voltage transformers are used to acquire the appropriate data. The proposed scheme also carefully determines the ground distance element reach settings by calculating the apparent impedance while considering mutual coupling for all practical system configurations from the ANN; this eliminates the need for a compensation factor. The results of the apparent impedance (R + jX) calculated by the proposed adaptive and the conventional schemes, showed an average percentage error of (0.06% and 0.02%) and (15% and 41.5%) respectively. Having obtained this result, the performance of the proposed adaptive scheme showed the exact fault location with a higher accuracy when compared with a compensated conventional scheme.

中文翻译：

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互耦线路自适应距离保护方案

在正常情况下，零序电流的可用性决定了连接到相互耦合的并联线路上的距离继电器的操作精度。当这不可用时，系统采用不同的补偿系数，如果计算不当，则会在继电器操作中引入误差。本文所述的拟议自适应保护方案由三个模块化人工神经网络模型 (ANN) 组成。这是使用前馈非线性反向传播 Levenberg-Marquardt 算法开发的，该算法确定相互耦合线的实际状态。连接到电流和电压互感器的远程终端单元用于获取适当的数据。所提出的方案还通过计算视在阻抗，同时考虑来自 ANN 的所有实际系统配置的互耦合来仔细确定接地距离元件范围设置；这消除了对补偿因子的需要。由提出的自适应方案和传统方案计算的视在阻抗 (R + jX) 的结果分别显示平均百分比误差为 (0.06% 和 0.02%) 和 (15% 和 41.5%)。获得这一结果后，与补偿的传统方案相比，所提出的自适应方案的性能以更高的精度显示了准确的故障定位。由提出的自适应方案和传统方案计算的视在阻抗 (R + jX) 的结果分别显示平均百分比误差为 (0.06% 和 0.02%) 和 (15% 和 41.5%)。获得这一结果后，与补偿的传统方案相比，所提出的自适应方案的性能以更高的精度显示了准确的故障定位。由提出的自适应方案和传统方案计算的视在阻抗 (R + jX) 的结果分别显示平均百分比误差为 (0.06% 和 0.02%) 和 (15% 和 41.5%)。获得这一结果后，与补偿的传统方案相比，所提出的自适应方案的性能以更高的精度显示了准确的故障定位。