# A Setting Optimization Ensemble for a Distributed Power Grid Protective Relay
## 1 Introduction  
With the continuous advancement of new power electronic devices and emerging energy equipment, the power system is experiencing escalating complexity and expanding coverage. Currently, the power system is swiftly evolving towards a large-scale power supply, cross-regional transmission, and high-voltage DC transmission. Consequently, the demands for configured relay protection facilities are progressively becoming more stringent and standardized [1; 2; 3]. Relay protection in electric power systems generally comprises relay protection devices, current transformers, voltage transformers, and other elements. The relay protection device utilizes collected current and voltage signals to perform logical operations based on preset protection trigger conditions. Upon meeting these conditions, a protection trigger signal is generated to either isolate the fault area or switch the circuit, ensuring the effective protection of power equipment [4]. The calculation of the traditional relay protection device's setting value primarily relies on the upstream and downstream cooperation method. This entails setting up the corresponding backup protection relay device in coordination after the remote relay device has been configured [5]. Traditional fault detection and location methods have limitations, potentially lacking real-time monitoring and accurate positioning capabilities. Manual intervention becomes necessary with the system protection's \"four characteristics\", which represent the sensitivity, selectivity, stability, and quickness of the system relay protection; requirements cannot be met, imposing high demands on operators [6; 7; 8; 9]. To address these challenges, a proposed online adaptive protection coordination scheme based on the numerical directional overcurrent relay (DOCR) and a commercial interior point optimization solver is presented in document [10]. Additionally, the literature [11] introduces a multi-characteristic relay to tackle coordination issues during network failures, accompanied by a self-contained protection relay designed as a backup. Furthermore, the literature [12] analyzes methods for distinguishing the internal faults of relay protection under a transformer surge and overexcitation conditions, effectively enhancing the performance of differential protection. In addition, an adaptive relay protection method for distribution systems with electronically coupled distributed energy sources is presented in reference [13]. In document [14], K-means clustering is employed to define the setting group of overcurrent (OC) relays. This approach enhances the reliability and performance of OC protection. A cyber-physical automatic testbed for relay protection using real-time digital simulators (RTDS) has been developed in reference [5] to modify the settings online. Despite these advancements, the traditional power system is often accompanied by power transmission congestion and related problems, and the demand for a smart grid arises at the historic moment [15; 16; 17]. Considering the rapid progress in computer technology, power electronics, and information electronics, a comprehensive approach is essential for the innovation and optimization of smart grid technology to continuously enhance safety and stability in power grid system operations [18; 19; 20; 21]. Simultaneously, the advancement of new energy sources and energy storage has presented fresh demands for the power grid, consequently introducing new challenges to relay protection [22; 23; 24]. As distributed computing technology matures, the utilization of distributed computing platforms can effectively facilitate the global optimization of relay protection setting design [25; 26]. Intelligent optimization algorithms based on distributed technology have been widely employed to calculate global protection setting values. Reference [27] introduces a protection scheme utilizing the support vector machine (SVM) method to detect bulk DG trip after an electrical system failure, ensuring the subsequent distance relay operates correctly.