應用專家經驗法則庫於配電系統開關操作之決策

Applying Heuristic Rule Base to Decision Making of the Switching Operations for Power Distribution Systems

吳英明(Ying-Ming Wu)

指導教授 ： 蕭瑛東

淡江大學/工學院/電機工程學系博士班/博士(2012年)

https://doi.org/10.6846/TKU.2012.01022

摘要

電力系統包含發電系統、輸電系統、配電系統等三大部份。傳統配電系統運轉在輻射狀架構上，將電能由發電廠經由變壓器以及輸電饋線傳輸分配給各客戶。配電系統為電力系統之最下游，涵蓋層面遼闊，電力輸送從主變電所或二次變電所之主變壓器、饋線、分歧線及配電變壓器、接戶線、線路接頭甚至電表等等，都會造成線路損失，同時會降低系統運轉效率。在配電系統上裝設各類開關以方便管理，如何決定配電系統開關操作之策略以達到電壓維持、電能損失降低、及提升系統備轉容量是一極為值得重視之課題。本論文提出專家經驗法則庫來解決配電系統開關操作之決策問題，配電系統為輻射狀之結構，饋線網上設置分段開關以將饋線分成數個區段，以儘量縮小故障區域。饋線之間則設置常開的聯絡開關以互相連接，當某一饋線發生事故或進行維修時，可經由另一條饋線繼續供應電力。由於配電網路非常龐大與複雜，因此如何適當地操作饋線網上所設置的這些開關，而使配電系統於安全、可靠與經濟等多重目標下運轉，各國電力公司均投入相當的關注。配電系統操作之決策問題通常考慮的問題包括：如何復原最大停電區負載量以增加供電可靠度？如何決定最少的開關操作次數以降低操作成本？如何維持最小的電壓變動量以提高電力品質？如何降低饋線電流及變壓器負載量以減少電能損失？如何維持放射狀網路結構以滿足操作上的限制？如何決定開關操作以確保運轉安全？本論文考慮這些系統之實際運轉情況，發展一個新的數學模式，使之更能符合電力系統實際操作狀況。配電系統的安全與經濟運轉關鍵在經由分斷開關、連絡開關與斷路器操作之適當決策，使配電饋線的事故工作停電範圍及線路損失盡量地小。本研究以專家經驗法則庫的方法，發展輔助配電系統決策操作之專家系統，主要有兩個目標，第一，於故障發生時決定隔離故障點，以防止故障範圍繼續擴大並進行決定故障斷電區域的復電計畫。第二，於正常工作情況下，依春夏秋冬四季的負載模型，經由操作分段開關的開閉狀態，將各個負載適當地分配給不同的主變壓器與饋線，藉以達到減少饋線損失及負載平衡的目的。

關鍵字

電力系統 ； 發電系統 ； 輸電系統 ； 配電系統

並列摘要

Power system consists of three parts: the generating system, transmission system and distribution system. In general, the distribution system is running in the radial structure. The electrical energy is generated from power plants through the transfer of the transformer and transmission feeder assigned to each customer. Distribution system is the most downstream of the power system and covers a vast level. Distribution system transmits power energy from the main substation to secondary substation transformers, feeders, branch line and the customers. Due to the feeder line, and the meter, and so on, thess facts will resul in line losses, and also reduce the efficiency of system operation. Installation of various types of switches in the distribution system to facilitate management, how to determine the distribution system switching operation strategy to achieve the desired voltage, to reduce energy losses and to enhance the system spinning reserve capacity are the subject of an extremely worthy of attention. This thesis presents the heuristic rule base to solve the decision problem of the distribution system on switching operation. The power distribution system is using radial structure with feeder-line setting section switch to the feeder for dividing into several sections, so as to minimize the fault area. The feeder is set between the normally open contact switch connected to each other, when a feeder of an accident or for maintenance, continue to supply electricity via other feeders. The distribution network is very large and complex, so how to properly operate the feeder line set these switches, leaving the distribution system in the multiple goals of safe, reliable and economic operation, the power companies have been received considerable attention. Usually the decision problem of the distribution system operation includes: how to recover the largest power outage area load to increase the reliability of power supply? How to determine the minimum number of switching operations to reduce operating costs? How to maintain a minimum amount of voltage variation to improve power quality? How to reduce the feeder current transformer load to reduce the energy losses? How to maintain a radial network structure to meet the operational limitations? How to determine the switching operation to ensure the safety of operations? This dissertation considers the practice of the distribution power system to develop a new mathematical model so that it can meet the practical situation of the power system. It is a key point of the safe and economic distribution to control sectionalizing switches, tie switches and breakers for minimizing faults, area of uncharge and power losses. This work will develop an expert system to aid distribution operation by an artificial intelligent approach. There are two goals in this project. First, the expert system will select suitable isolation points to limit the fault area. Then, it will propose restoration planning. Second, in normal system opertion, it is essential to make the loads on feeders and main transformers as balanced as possible.

並列關鍵字

Power system ； generating system ； transmission system ； distribution system

參考文獻

[48] D. L. Wall, G. L. Thompson, and J. E. D. Northcote-Green, “An Optimization Model for Planning Radial Distribution Network”, IEEE Trans. on Power Apparatus and Systems, Vol.98, pp.1061-1067, 1979.

[1] R. J. Kafka and other, “System Restoration Plan Development for a Metropolitan Electric System”, IEEE. Trans. on PAS, No. 8, August 1981, pp. 3707-3713.

[2] C. S. Chang and T. S. Chung, “An Expert System for on-Line Security-Economic Load Allocation on Distribution Systems”, in the proc. of the IEEE/PES 1989 Transmission and Distribution Conference, Paper 89 TD 417-7 PWRD.

[3] F. Hayes-roth and other. Building Expert Systems, Addison-Wesley, Inc. 1983.

[4] R. Daris, B. Buchanan and E. Shortiffe, “Production Rules as Representation for a Knowledge-Base Consultation Program”, Artificial Intelligence, Vol.8, 1977, pp. 15-45.