本年度計畫將評估先前所完成之輸電線保護電驛系統各項性能指標對於資料通信傳送過程中所產生延遲和位元錯誤的容忍度。吾人將採用Network Simulator v.2 軟體與排隊理論來進行相關研究。首先，建立資料延遲和資料遺失的模擬系統，然後提出數學分析的模型，以當作未來整個保護電驛系統修正設計的依據。所研提的保護電驛系統在解決傳送資料通信品質的問題之後，將可使得整套系統的安全性與實用性大幅地提升。
This project, based on two-terminal synchronous measurements technique and my previous studies, is devoted to the study for the reliability of the proposed GPS-PMU based protective relay and the communication quality for transmission lines system. The complexity and specialty of the protective relaying system and communication network configuration will be taken into account. The research has an orientation towards practical considerations such that the research results can also be integrated in the existing EMS/SCADA systems of power companies. The research task includes the reliability performance evaluation of the protective relaying configuration and the communication quality. The two-year proposal is planning to carry out in the following two stages:
The first year:
The project will utilize the fault tree analysis theory incorporated with Handbook of U.S. Military Electronics (MIL-HDBK-217F) to compute the failure rate and to evaluate the unavailability of the protective system. The research topics include the impacts of the different communication media, CT’s saturation, circuit breaker failure, etc. on the performance of the protective relaying system. The failure rate database system for the components and equipment of the protective system is first established. Then, the fault tree method will be utilized to analysis the reliability for different protective relaying configurations. Finally, the most feasible protective relaying configuration that is suitable for transposed/untransposed transmission lines is proposed.
The second year:
In this stage, the effect of the transmission delay and transmission bite-error of the operation data of the power system on the performance indices of the previously designed protective relaying system will be evaluated. The Network Simulator v.2 and queuing theory will be applied to the study. First, the simulation system model for the mentioned topics will be established. The tolerance of the relaying system with respect to data transmission delay and loss will also be examined. The evaluation results will be concluded to propose a mathematical model that can be utilized to modify the design of the proposed relaying system. After the problems for the data transmission quality being resolved, the security and availability of the proposed protective relaying system will be promoted significantly.
Keywords: Reliability, Communication quality, Communication protocols, Fault tree analysis theory, Queuing theory.
Fault tree analysis theory