【作者】 李明；

【导师】 韩学山；

【作者基本信息】 山东大学 ， 电力系统及其自动化， 2012， 博士

【摘要】 设备检修决策是电网运行中最为关键的问题之一,适宜的检修可为电网带来极大的效益,提高设备运行的效能,反之就会带来损失,影响电网运行的可靠性与经济性,一直以来该问题是学术界和工程界关注的焦点。随着测量、通讯、计算机等技术的进步,以设备监测为依据的状态检修逐步得到推广和应用。在这一背景下,若从设备个体行为看,实时依据性能监测的检修决策变得容易,使检修时机与设备性能实时关联,利于提高设备个体效能；而从电网整体运行角度看,由于各设备检修时机实时关联其性能而产生差异性,设备在实施状态检修时,不免会产生设备个体间、设备个体与电网整体运行间的矛盾和冲突,进而降低电网整体运行的效能。由此,为解决这一矛盾与冲突,必须对设备间检修时机差异性、设备检修与电网运行间的关系进行折中处理,以此为线索,本文对电网运行中设备的检修理论进行了深入研究,主要工作和创新成果体现如下：(1)在对已有的设备故障率研究成果归纳总结的基础上,利用全概率公式,给出计及设备健康状态、故障后维修及预防性检修共同作用的设备故障率评价和预测模型。其焦点体现在：设备健康指数与其故障率之间的关系,故障后维修、预防性检修与设备故障率之间的关系,设备检修决策的不确定性分析,设备故障概率、故障率、设备状态(可靠、不可靠)之间的关系。该研究实现状态监测环境下,计及检修的设备性能评价及发展趋势预测,是电网设备检修理论研究的基础。(2)提出电网设备状态检修策略评价方法。从设备个体与电网整体运行的角度,定义了计及检修作用的电网运行风险指标,并给出了相应的求解流程。依据该风险指标,综合考虑设备个体性能及其在电网中的作用,针对设备检修,提出设备重要性概念,对相关指标进行量化,实现设备检修策略在个体与电网运行间进行折中表达。基于此,提出设备状态检修下的电网检修方案评价方法。该研究从电网整体运行的角度,实现计及电网运行风险的设备检修过程中设备个体重要性分析与电网检修方案评价,为电网中设备状态检修决策提供重要的依据。(3)提出电网状态检修的新概念,构建电网状态检修模型并给出相应的求解方法,使电网设备状态检修决策从设备个体层面提升到电网层面。为解决电网整体运行与设备个体间的矛盾和冲突,在分析设备检修与电网运行间的辩证关系的基础上,给出了电网状态检修的概念,从故障、检修两个角度分别定义故障风险、检修风险,并以研究周期内两种风险之和最小为目标,构建电网状态检修决策模型,并给出相应的解决方法。该模型和方法将设备检修、运行以及电网整体性能在概率的引导下相互牵制,算例分析表明了电网状态检修概念、模型与求解方法的正确性和有效性。(4)在电网状态检修概念下,针对设备在拓扑上仅与变电站关联的设备状态检修决策问题,建立变电站状态检修决策模型。对变电站实施状态检修决策必要性阐述的基础上,提出在设备状态监测、预测基础上的设备状态转移马尔科夫过程,基于马尔科夫过程方程实现研究周期内设备多状态概率的求解。继而给出因检修时机而变动的检修风险与故障风险的表达,并以二者之和最小为目标构建变电站设备状态检修决策模型,利用遗传算法实现模型的求解,通过算例阐明本研究的必要性和有效性。该研究是电网状态检修理论的基础,是实施复杂电网状态检修分解协调决策过程中的重要环节。(5)在设备检修理论研究的基础上,构建和开发设备状态检修决策的辅助支持系统。从电网整体运行层面对检修策略进行定量的风险分析,具体包括电网运行风险评估、设备重要性评价及检修方案评价等三项功能,提供友好的人机交互界面,同时与SQL数据库存储与处理技术结合,便于结果查看和分析。通过在山东电网及多个地区电网的应用,验证了该系统对应理论和方法的正确性和有效性。更多还原

【Abstract】 Equipment maintenance decision-making is one of the most crucial issues in the power grid. Appropriate maintenance can bring great benefits to the power grid, and increase equipment operation efficiency. On the contrary, it will cause sacrifices, and affect the reliability and economic of power grid operation. So, maintenance decision-making has been always the focus of attention of the academic and engineering.Now, the concept of condition-based maintenance (CBM) has been receiving increasing attention and trust with the development of power system technology. It is based on the equipment monitoring and diagnosis. The appropriate maintenance time for the single equipment can be found under the background of CBM, and this not only makes the decision of maintenance easy, but also improves the efficiency of the single equipment. However, from the perspective of the whole power transmission system, the appropriate maintenance time of the equipment depends on its own performance instantly, which arouses the discrepancy between the equipment and the power transmission system. Once this discrepancy can not be compromised, it will certainly arouse contradictions and conflicts between individual and whole, and loses the integral efficiency.Under this background, in order to solve those contradictions and conflicts, it needs a good compromised mechanism to deal with the differences of equipments maintenance time and the relationship between equipments maintenance and integral efficiency of transmission system operation. Based on this line, the maintenance theory has been researched in this thesis for transmission system equipments. The main works and innovative achievements of the thesis are as follows:1. Research on equipment failure rate expression and prognostic technology. Based on the summarizing the relative outcome, from the viewpoint of probability, the equipment failure rate model is given taking into account the device status, corrective maintenance and preventive maintenance using the total probability formula. The focus is reflected like:the relationship between health index and the equipment failure rate, the role of corrective maintenance and preventive maintenance, the probability of maintenance decision making, the relationship between the probability of equipment failure, failure rate and equipment status (reliable, unreliable). In short, with the existing research results, the comparatively systematic analysis and research to the failure rate has been carried on in this part, which gives a precondition for risk-based transmission system maintenance theory.2. Maintenance strategy evaluation method was proposed taking into account the power grid operation risk. On the basis of calculating expected energy not served in the power grid, the cost risk indicators, security risk indicators and environmental risk indicators were deduced from the comprehensive view of equipment individual and the whole power grid. According to the CBM needs, the concept of equipment importance (EI) was proposed. El index was to quantify considering the individual performance of equipment and overall operating performance of the grid. The order of maintenance was proposed according to El index. On the other hand, power grid maintenance strategy evaluation and sorting methods was given based on risk. The methods take into account the relationship between the equipment performance and the maintenance strategy. From the perspective of the whole power grid operation, the equipment important analysis and power gird maintenance strategy evaluation were given based on risk, which provide the quantitative basis for the CBM in power grid.3. On the analysis of dialectical relationship between equipment maintenance and system operation, the concept of condition-based maintenance for power grid (CBM-PG) is put forward. In CBM-PG, from the perspective of failure and maintenance, the failure risk and maintenance risk are defined. On the basis of the condition trend prediction for the transmission equipment, the mathematics model and corresponding solutions are presented to minimize the sum of failure risk and maintenance risk, and get a balance between the equipment maintenance, operation and the efficiency of power transmission system. The detail analysis of the RBTS-BUS6and IEEE-RTS79system demonstrates the validity and practicability of the proposed concept, which provides a necessary foundation for the further research on the cooperation decision-making between maintenance and operation of power systems.4. Under the study of condition-based maintenance for power grid (CBM-PG), the model and solution of condition-based maintenance for substation (CBM-S) was studied. The equipment involved in this paper were only associated with the substation from the view of the topology. The necessity of the research for CBM-S was discussed first, and the equipment condition in the research time was obtained by Markov process under the technique of state monitoring and forecasting. Furthermore, the quantitative expression of the failure risk and maintenance risk were provided, in which the maintenance time was the only parameter. Then, the decision-making model of CBM-S was established. The goal of the model was to minimize the sum of failure risk and maintenance risk, and the maintenance constraints were also considered in this model. The genetic algorithm was selected to solve the model. The analysis of simple example demonstrates the necessity and effectiveness of the study in this paper. This paper is the further study of the CBM-PG, and is an important part of the decomposition and coordination of the decision-making process for CBM-PG.5. Under the study of condition-based maintenance for power grid based on risk, a Decision Support System for CBM is built. The system has three basis functions:the risk assessment of power grid, the analysis of equipment important for maintenance and the analysis of equipment maintenance strategy based on risk. The system provides a friendly interactive interface, and is easy to use. It has been used in the Shandong power transmission system, and the results demonstrate the validity and practicability of the system.更多还原