使用MATLAB程式輔助排定變電所停電轉供表格之研究-以臺電臺北北區營業處淡水變電所為例

Abstract

以往台電二次變電所的一次側開關在維護時全變電所需停電並由其他變電所轉供，常需要由電力公司人員排定停電轉供表格並製作停電轉供示意圖，既耗時又費工，台電向外國採購的含故障偵測、隔離及復電功能系統設備既昂貴且不是每個區處都有此設備，於一次側發生事故時造成全變電所停電時如無法即時排定停電轉供表格算出轉供後主變壓器負載及饋線設備是否能承擔，則會造成停電時間增加，如能利用電腦程式排定轉供表格減少人為判斷時間，不但可以降低電力公司停電損失，也可以減少因停電時電力公司人員因太緊張所產生的錯誤。 本文以台北縣淡水變電所為例並利用MATLAB軟體撰寫程式來排定停電或維護時之轉供表格。首先將目前淡水變電所的連絡情形及實際數據鍵入電腦程式中，然後將資料樹化、排序並以搜尋法來找出應轉的所外饋線，並考慮重要用戶饋線(如醫院、重要指揮機關、警察局等)需最優先轉供、單一對外連絡饋線第二優先轉供、多條對外連絡饋線最後轉供並以外連饋線電流最小者為最優先吸載等轉供方式。應用本研究，淡水變電所一次側開關需維護時僅需輸入當時饋線電流情形及當時主變壓器負載情形即可自動排定所外轉供饋線，於平日只需注意變電所主幹線外連情形即可。本研究也將主變容量過載時之卸載功能加入，透過本研究發展之程式可找出系統弱點，可當作系統規劃時之參考。 本研究目前僅發展到所外轉供，尚無考慮經匯流排轉供、從已復電饋線轉供及分段轉供等功能，但可作為未來的研究方向。

When the primary side switch equipments of secondary substations of Taiwan Power Company were maintained, the electrical power supply of the whole substation must be interrupted and the load was transferred to near substations. The load transfer tables and load transfer demonstration charts were required for such maintenance and currently were made by man work, consuming much time and human resources. The equipments for fault detection, isolation, and restoration are very expensive and are not available to all branches. When the outage happened, the load transfer tables could not be immediately made causing more service interruption time. If the computer program was used to make the load transfer tables, the time for deciding the load transfer would be saved and the losses and the manmade mistakes for the power interruption would be reduced. This thesis takes the Dan-Shui substation as an example and uses MATLAB software to write programs to make the load transfer table for outage or maintenance of secondary substations. Firstly, input the connection conditions and some real data of Dan-Shui substation to the computer program. Then set up the data by tree type, sort the data and use search techniques to find the distribution feeders for load transfer. And consider the important users feeders(such as hospitals, important institutions for directing, police station, etc) have the most priority for load transfer, uni-out-connected distribution feeders are less prior, multi-out-connected distribution feeders are least prior and the distribution feeders out connected which have least current get the most priority to take the load. If applying this study, the load transfer could be automatically arranged just by inputting the feeder current values and the main transformer loading conditions at that time to the computer when the primary side switch equipment needs maintenance. The computer program also includes the load-shedding function considering the condition when the main transformers are overloaded. So the system weak points can be found through the computer program developed by this study and can act as reference to system planning. This thesis only considers the load transfer outside the substation, not yet the bus load transfer, restoration feeder load transfer and multi-section load transfer. Suggest that these three kinds of load transfer can be the future work.