综合防御由偶然故障演化为电力灾难——北美“8·14”大停电的警示

THE WAY FROM A SIMPLE CONTINGENCY TO SYSTEM-WIDE DISASTER ——Lessons from the Eastern Interconnection Blackout in 2003

电业界在技术层面上思考过1996年的北美西部大停电,又在经济层面上反思过2000年的加州电力危机,却没有充分认识到在电力市场环境下电力系统发生更大停电灾难的可能性,也未能在2003年北美东部“8·14”大停电的演化长过程中予以制止。其中,在思维方式上的教训为:应该在统一的框架下,有机地结合电力体制、市场运营、监管规则、规划设计、仿真分析、信息工程、调度运行、控制技术、科技投入和人才培训等因素进行反思。用仿真重现相继停电的全过程固然必要,但更重要的问题是:①人们分别有22 min,9 min,5 min,29 min的时间来阻止第2,3,4,5个相继开断,为什么却无作为地听任其发展为系统振荡?②为什么大范围的停电竟然长达29 h?这些案例是我国电力工业界的极好教材。“8·14”大停电,既暴露了电力市场对电力系统稳定性的负面影响,又反映了互联电网相继开断的严重后果。技术方面的教训包括必须完善并协调各级信息系统,提高在线安全稳定的量化分析及控制决策能力,研究针对各种灾变的防御控制计划,协调预防控制和紧急控制,采用自适应的系统保护装置以及电力系统和电力市场的动态仿真器等。

WSCC blackout in 1996 has been analyzed basically from a pure technical viewpoint and California electricity crisis in 2000 has been discussed from a pure economic viewpoint. However, the possibility of a much more severe blackout had not been cognized before the occurrence of Eastern Interconnection blackout in 2003. As a result, this catastrophe didn't be held out though there is a quite enough time period to arrest the global blackout between two cascading line tripping. Investigations on this catastrophe should be performed in a uniform framework that integrates all important factors, such as the organization of electrical power industry, market operation and surveillance, power system planning, analysis tools, dispatch strategy, information engineering, control schemes, R&-D and personnel training, etc. Some important questions are: ① why the cascading tripping can't be stopped since there are respectively 22, 9, 5, 29 minutes to hold out the 2nd, 3rd, 4th, 5th cascading tripping?②why the wide area blackout lasted for as long as 29 hours? The negative effects of electricity market on power system security are analyzed. Lessons on technical aspects include properly sharing information, on-line quantitatively analyzing power system security, on-line refreshing control decision, coordinative defense schemes; coordinating preventive control with emergency control, adaptive system protection schemes, dynamic simulator of both power system and electricity market, etc.