输电网安全性需求评估指标集的构建

Evaluation Indices Set Construction of Security Requirement for Transmission Network

输电网的安全运行是输电网企业的主要需求,输电网运行的安全性事故将造成输电网企业经济和社会效益的严重损失。输电网企业期望输电网运行中能够经受可能的扰动,以保证电网和设备的正常运行,从而不中断输电服务。通过分析输电网利益相关者的需求满足程度,可以评估输电网运行的整体状态。基于输电网运行的随机特性,采用风险评估方法,构建安全性需求评估指标集,提出安全性风险评估指标的计算模型和方法。相比较传统电网安全性研究,引入情景分析方法,将在某种运行方式下输电网发生某种元件故障或不发生元件故障作为一个情景,综合考虑了多种随机因素,建立情景的概率模型;在特定情景下研究电网的各类安全问题,通过安全判据指标综合判断情景的安全性,进而采用最小控制代价衡量干扰对输电网运行造成的后果;通过抽样方法,得到各情景发生的概率和后果,计算风险价值、条件风险价值指标,以评估系统的安全风险。

The core requirement of transmission network enterprise lies in the safe operation of transmission network. Failure in satisfying this requirement will result in disastrous loss on economic and social benefits.Hence,transmission network is expected to possess the capability of enduring possible disturbances in order to ensure the normal operation of grid and equipment,as well as avoid the power transmission interruptions.Through the analysis on the requirement satisfaction of transmission system stakeholders,the overall status of transmission network operation can be evaluated.Based on the stochastic characteristics of transmission network operation,this paper used a risk assessment method to construct evaluation indices set for the security requirement,and proposed the calculation model and method of security risk assessment indicators.Compared with the traditional researches on grid security,a scenario analysis approach was introduced.In detail, breakdown or normal operation of certain components under certain specific operating modes was modeled as a scenario,and a probabilistic model for the scenario was constructed with taking into consideration a variety of random factors.All kinds of security problems were studied in the specific scenarios.The security of the situations could be evaluated comprehensively according to the safety criterion indices;therefore a minimum expense of control could be adopted to measure the consequence of the disturbance on the transmission network operation.Through sampling method,the probability and consequence of each situation occurrence could be acquired;and with the assistance of calculating value at risk and conditional value-at-risk,the security risk of transmission network could be evaluated properly.