【作者】 范云滩；

【导师】 刘开培；

【作者基本信息】 武汉大学 ， 电力电子与电力传动， 2013， 博士

【摘要】 调峰电厂在峰谷差较大的电网中起着重要的调峰作用,其运行可靠性对电网的安全稳定运行具有重要意义。调峰发电厂设备启停、功率调节等较普通电厂更为频繁,对该类型电厂厂用电设备及系统的可靠性要求更为严格。本文对调峰用天然气发电厂厂用电系统的可靠性计算方法、风险评估方法以及可靠性提高措施的方法进行了较为全面系统的研究。本文采用符号动力学方法,对厂用电系统中的元件进行了可靠性及风险描述,并在此基础上构建了厂用电系统风险评估方法,并通过全寿命周期成本作为约束条件,对可靠性改进方法进行了分析。本文首先选取了一组适用于发电厂厂用电系统可靠性计算的指标,根据马尔科夫状态方程分别构建厂用电系统中功率元件和操作元件的可靠性模型。功率元件以包含正常、故障及计划停运的马尔科夫三状态模型予以模拟,操作元件以包含正常、计划停运、非计划停运及误动拒动予以模拟。根据各种状态之间的转化关系导出各状态的概率计算公式,结合厂用电设备历史故障记录对可靠性指标进行计算。应用上述计算方法对某天然气发电厂厂用电设备的可靠性进行了计算。在厂用电设备及系统可靠性模型的基础上,应用蒙特卡罗方法,对调峰用天然气发电厂厂用电系统的可靠性及风险评估进行了研究。根据发电厂历史发电量曲线构建多级水平负荷模型,然后采用[0,1]均匀分布模拟所有设备的实时状态,进行重复多次模拟,统计计算系统的可靠性指标。并在此基础上进行预想故障分析,计算所有会引起机组停运的故障概率,然后将之与电厂多级水平负荷模型进行比较,最后得到风险指标LOGP (缺发电概率)和EENG(缺发电量期望)。应用上述方法对某天然气发电厂厂用电系统的运行风险进行了评估分析。根据可靠性计算和风险评估结果,本文提出了调峰用天然气发电厂厂用电系统的可靠性改善措施。并根据全寿命周期成本理论,提出了可靠性优化措施的费用分解模型,包括设备投资费用、设备运行维护费、停电损失费用、退役成本以及其它费用。引入敏感性分析理论,评估发电厂风险对各设备可靠性的敏感性,根据分析结果对各方案进行技术性及基于LCC理论的经济性对比分析。应用上述方法制定了某天然气发电厂厂用电系统的可靠性改善优化措施。更多还原

【Abstract】 Main peaking-load power plant plays an important role in a power grid with increasing peak-valley difference and its operation reliability, which are of great significance to the safe and stable operation of power grid. The start/stop and power regulation of the equipments are more frequent than those in ordinary power plants, therefore the requirements to the reliability of the equipments and systems are much more rigor. This paper carries out a comprehensive and systematic research on the reliability calculation methods, risk assessment methods and reliability improvement measures for auxiliary power system of peaking natural gas power plant.This paper adopts symbolic dynamics method to describe reliability and risk description for auxiliary power system. Based on this description, risk evaluation method is constructed, and Life Cycle Cost(LCC) is used as constraints to evaluate the effect of reliability improvement methods.Firstly, this paper selects a set of equipment reliability indicators applicable to the reliability calcution of auxiliary power system. The reliability model of power components and operation components of auxiliary power system are built respectively based on the Markov equations. The power components are simulated by a three-state Markov model which contains normal, failures and planned outages state, while the operation components are simulated with normal, planned outages, unplanned outages and malfunction state. The probability calculation formulas are derived according to the relationship between these states, and the reliability indicators are calculated based on the history equipment fault records of auxiliary power system. The proposed method is applied to calculate the reliability of the equipments of auxiliary power system of Huizhou LNG power plant.On the basis of reliability model of auxiliary power equipments and system, this paper carries out a study on the reliability and risk assessment of the auxiliary power system of peaking natural power plant based on Monte Carlo risk assessment theory. The multi-level load model of such power plant is built in accordance to the history power generation curve, then the reliability index for each load node of the system are calculated statistically by using the [0,1] uniform distribution, to study the real-time status of all devices and multiple simulations. By applying assumed failures on the basis of these results, the failure probability that may cause the unit outages is calculated and then compared with the multi-level load model of the power plant, therefore the risk index including LOGP (Loss of Generation Probability) and EENG (Expectations of Energy Not Generated) are resolved. The proposed method is applied to perform the operation risk assessment of auxiliary power system of Huizhou LNG power plant.According to the results of reliability calculation and risk assessment, this paper proposes the reliability improvement measures for the auxiliary power system of peaking natural gas power plant. The cost decomposition models of these measures, which contain the cost of equipments’ investment, the cost of equipment operations and maintenances, the cost due to blackout loss and the cost of retirement, etc. are analyzed based on the full LCC theory. Sensitivity analysis theory is introduced to evaluate the sensitivity of the power plant risk to the reliability of the equipments. According to the analysis results, the comparation of these measures are performed based on the LCC theory from both the technical and economic aspects. The proposed method is applied to design the reliability improvement measures of auxiliary power system of Huizhou LNG power plant.更多还原