Abstract The modern power distribution networks are very complex due to the growing integration of distributed generators in recent years. Optimal coordination of directional overcurrent relays (DOCRs) used for protection of such complex networks is a highly constrained and nonlinear optimization problem. In this paper, a new optimization algorithm called Sine Cosine Algorithm (SCA) is used first time to solve the optimal coordination problems of DOCRs. SCA is a recently proposed population-based algorithm used for solving highly nonlinear optimization problems. The cyclic pattern of sine and cosine function allows a solution to be re-positioned around another solution. This can guarantee exploitation of the space defined between solutions. The effectiveness of SCA in solving the optimal coordination problems of DOCRs is tested on different fault data generated on 3-bus, 8-bus, 15-bus and 30-bus test systems. The results clearly show that the effectiveness of the proposed algorithm is superior in reducing the overall operating time of primary relays compared to the recently published optimization algorithms for DOCRs coordination. Also, the proposed algorithm is robust in maintaining the coordination between primary and backup relay pairs. Compared to existing optimization algorithms, the proposed algorithm has reduced coordination interval time between primary and backup relay pairs.

中文翻译：

---

使用正弦余弦算法优化复杂配电网络中定向过流继电器的协调

摘要 由于近年来分布式发电机的日益集成，现代配电网络非常复杂。用于保护此类复杂网络的定向过流继电器 (DOCR) 的优化协调是一个高度受限的非线性优化问题。在本文中，首次使用一种称为正弦余弦算法（SCA）的新优化算法来解决 DOCR 的最优协调问题。SCA 是最近提出的一种基于群体的算法，用于解决高度非线性的优化问题。正弦和余弦函数的循环模式允许一个解围绕另一个解重新定位。这可以保证利用解决方案之间定义的空间。在 3 总线、8 总线、15 总线和 30 总线测试系统上生成的不同故障数据上测试了 SCA 在解决 DOCR 优化协调问题方面的有效性。结果清楚地表明，与最近发布的 DOCR 协调优化算法相比，所提出算法的有效性在减少初级继电器的整体操作时间方面更为优越。此外，所提出的算法在维持主要和备份中继对之间的协调方面是稳健的。与现有的优化算法相比，所提出的算法减少了主备中继对之间的协调间隔时间。结果清楚地表明，与最近发布的 DOCR 协调优化算法相比，所提出算法的有效性在减少初级继电器的整体操作时间方面更为优越。此外，所提出的算法在维持主要和备份中继对之间的协调方面是稳健的。与现有的优化算法相比，所提出的算法减少了主备中继对之间的协调间隔时间。结果清楚地表明，与最近发布的 DOCR 协调优化算法相比，所提出算法的有效性在减少初级继电器的整体操作时间方面更为优越。此外，所提出的算法在维持主要和备份中继对之间的协调方面是稳健的。与现有的优化算法相比，所提出的算法减少了主备中继对之间的协调间隔时间。