臺灣博碩士論文加值系統

對於世界現行輸電網而言，「輸電效率」與「電網安全性」乃輸配電公司之兩大考量，而歷經國內外數次大停電（如美加大停電、七二九大停電、八一五大停電、印度大停電…等）所帶來的衝擊與影響，輸電網的重要性已自不待言。欲提升電網安全性、輸配電裕度與彈性，可藉由直接監測輸電線與其附近環境的即時參數與資訊（如電流、線溫、環境溫度…等），進一步分析電網之即時情況，供輸配電單位做安全監測與輸配電評估。而若需大範圍監測電網安全，最佳方案即將「物聯網」導入電網，以無線監測的技術，做為輸電網安全監測系統的基礎。「物聯網」一詞可說是過去十年最火熱的科技名詞之一，利用因地制宜的前端設備與無線感測器網路，蒐集所需參數並進行分析，將分析結果反饋並用於服務使用者。然而，高壓輸電線周圍之超強電磁波會嚴重干擾無線通訊與電子設備運行，故其技術屏障相較其他物聯網產業高得多。本團隊歷經多年研究，成功克服此技術屏障，開發出一套搭配可抗電磁波干擾之超高壓輸電線實時監測之物聯網系統，量測多種輸電線參數，其中，本論文所分析之參數為監測設備所量測之三軸加速度，計算輸電線之垂度，以避免輸電線垂降過度、觸碰到地面或植被進而造成的接地故障。本研究主要分析系統於三個月內穩定運行所蒐集之數據，計量輸電線垂降值，並且與理論值做比對，其相關係數高達0.8603，平均絕對誤差僅0.44%，輔以實地量測結果驗證，足以證明此系統之準確性、可靠性與耐久性。此外，本研究亦列出分別懸掛於三相線路之設備量測資料並加以對照，充分顯示物聯網技術應用於超高壓輸電網內之可行性。此系統不僅能克服現在其他電網監測方法所無法克服之可行性與建置成本問題，其無線通訊與物聯網技術更使系統具有可廣佈、進行大範圍電網監測的絕佳優點。本研究之目的與願景為針對輸電網之情況進行實時分析，進而提供電力公司適當的調度建議，不僅提升調度彈性，更能確保電網運行無虞，為國家安全與產業發展盡一份心力。

For power companies around the world, transmission efficiency and power grid safety are two of the most important issues. The importance of the power grid safety goes without saying, after witnessing the impacts of a few power outages, such as the Northeast blackout of 2003, the 729 and 815 blackouts in Taiwan, and the 2012 India blackouts. The safety, efficiency and flexibility of high/extra-high voltage transmission lines can be improved by conducting real-time analyses on the parameters relating to the directly monitored transmission lines and their surrounding areas. The real-time information is criterial to power companies in power grid safety monitoring and power dispatch decision making. To monitor the safety of large scaled power grids, the best solution is to introduce “Internet of Things (IoT)” to power grids and use an IoT-based safety monitoring system on power grids. “IoT” has been one of the hottest terms in technology industries. An IoT monitoring system employs a wireless sensor network at the front-end sensing module to collect required local parameters for further analysis, and the analysis results can be used to improve various services. Nevertheless, the strong electromagnetic field around high/extra-high voltage lines is quite a technical barrier for electronic devices, which is much more challenging compared to other IoT applications. But the technical barrier has been removed and a reliable monitoring system for power grids that directly measures parameters on and around high voltage transmission lines in real time has been developed. In this research, a transmission line sag system is proposed. In this system, a three-axis accelerometer is used to measure transmission line sags, preventing the monitored transmission line from touching objects beneath it, which might lead to ground fault and even large-scale power failures. This study analyzes measured sag values collected during a seven-month stable operation and compares the measured values with theoretical values. The correlation coefficient of the two types of the sag values is 0.8603, and the mean absolute percent error (MAPE) is only 0.44%. Moreover, the accuracy of the measured sag values has been verified by comparing the values with field measurements. These results confirm the high accuracy, reliability and durability of the proposed sag monitoring system. In addition, this study examines the measurement results obtained from the devices placed on the three phases of a transmission line to verify the feasibility of applying the IoT technology to EHV transmission systems. The results show that this proposed sag monitoring system has overcome the challenge of the strong electromagnetic field around a transmission line with high/extra-high voltage. It reduces excessive construction costs when using other power grids monitoring systems. By adopting the IoT technology, the proposed system is able to be widely implemented in large-scale power grid monitoring. And, the line sag information can be used as power dispatch suggestions. The research results and conclusion provide criterial information not only to improve the flexibility of power dispatch but also to ensure the safety of power grids.

誌謝 i
中文摘要 v
Abstract vi
Table of Contents ix
List of Figures xiii
List of Tables xvii
Chapter 1 Introduction 1
1.1 Background 1
1.2 Motivation and Purpose 3
1.3 Thesis Organization 6
1.4 Reach Contributions 6
Chapter 2 Literature Review 9
2.1 Brief Overview of Taipower System 9
2.2 Transmission Conductors in Taiwan 11
2.3 Sag Measurements 14
2.3.1 Mechanical Estimations 15
2.3.2 Signal Information 17
2.3.3 On-line Robot 19
2.3.4 IR Laser Scanning 20
2.3.5 Image Processing 21
2.3.6 Magnetic Measurement 22
2.4 Summary 22
Chapter 3 Materials and Methods 27
3.1 Sag Monitoring System 27
3.1.1 Sag Measuring Devices 30
3.1.2 Experimental Information and Parameters 34
3.2 Line Equations 36
3.2.1 Basic Catenary Equations 36
3.2.2 Catenary Equations at Inclined Spans 38
3.3 Line Temperature Obtained from IEEE Std. 738-2012 42
Chapter 4 Results 47
4.1 Sag Values Obtained from Catenary Equations 47
4.1.1 Catenary Equation with the Influence by Heat Expansion 48
4.1.2 Theoretical Line Temperature Calculation Based on the IEEE Standard 738-2012 52
4.2 Sag Values from Sag Sensors 65
4.2.1 Sag Values Calculated from Angle 66
4.2.2 Comparison of the Measurement Results and Theoretical Results 68
4.2.3 Measuring Results from Different Sag Sensors 80
4.3 Sag Values Obtained from the Field Measurements 85
Chapter 5 Conclusions and Future Work 89
References 91
Appendix 95
Parabolic Approximation 95

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