【作者】 李万年；

【导师】 谢开贵；

【作者基本信息】 重庆大学 ， 电力系统及其自动化， 2010， 硕士

【摘要】 电力系统的可靠性与经济性二者相互影响,相互制约。根据可靠性成本效益分析曲线,电力系统可靠性随着投资成本的增加而增加。然而,电力系统中可能存在一种特殊的非同调现象,即:元件增装后,非但未能改善系统可靠性反而降低系统可靠性的现象。为了提高系统可靠性,降低投资成本,本文围绕配电网可靠性的非同调现象进行研究。针对配电网开关故障率较高,开关故障后对系统负荷影响较大的特点,结合辐射状配电网的结构特点,提出了计及开关故障的配电网可靠性评估分块算法。在使用现有分块算法计算配电网可靠性的过程中,加入了开关故障的影响分析,以达到更真实地反映系统可靠性水平的目的。算例分析表明,开关故障对配电网可靠性的影响不容忽略,为配电网可靠性非同调的辨识奠定了基础。给出了配电网可靠性非同调的定义,分析了配电网可靠性产生非同调的原因和可能元件,并指出开关设备是配电网产生可靠性非同调现象的主要元件。基于计及开关故障的分块算法分析了配电网可靠性非同调元件(如:断路器、隔离开关等开关设备)的可靠性影响,给出了配电网可靠性非同调的辨识方法。为分析非同调元件的经济性影响,从投资、运行维护、停电损失等费用对非同调元件进行了综合经济分析。开展了基于系统缺供电量的断路器非同调参数分析,包括断路器可靠性参数、其他元件可靠性参数、系统负荷、网络结构等。算例表明,非同调现象与这些因素均相关,分析结果与定性分析得到的模型相吻合。基于系统平均停电频率指标、系统平均供电可用率以及系统缺供电量三个指标对开关元件的非同调特性进行了分析。分析表明,基于不同的可靠性指标有可能得到不同的非同调辨识结果。在实际的非同调辨识中,可以根据系统用户的需求基于不同的可靠性指标进行分析。研究表明配电网中的确有可能存在非同调现象,通过可靠性非同调元件的分析,可有效提高配电网可靠性,降低系统投资、运行等综合成本。本论文受国家自然科学基金项目“电力系统可靠性非同调的理论及应用研究(50777072)”资助。更多还原

【Abstract】 Reliability and economy of power system influences and restricts each other. Based on the graph of reliability cost-benefit analysis, the reliability of power system improves while investing more. However, a particular phenomenon in power system called reliability non-coherence,which means the reliability of power system does not get better but probably worse when adding a new component in it,may be a special case against this classic theory.For the reason of a comparatively high failure rate of switching devices in distribution power systems (DPS), a section algorithm is presented to evaluate the DPS reliability considering the failures of switching devices. The impact of switching devices failures on the system reliability is analyzed when computing the reliability of DPS to get a more accurate value. Case studies show that the impact of failures on switching devices can not be ignored in DPS, Which laid the foundation for identification of non-coherence phenomena in DPS.The reasons of resulting in the non-coherence phenomena and the candidate non-coherence components in DPS are discussed according to the definition of non-coherence in power system reliability. Switching devices are the most possible non-coherence components in DPS. A method of non-coherence components identification is presented based on the section algorithm which considering the failures of switching devices. A comprehensive model considering the capital cost, maintenance and operating cost is proposed to analyze the impacts of non-coherence components on the system economy. According to the qualitative analysis on the impact of circuit breaker to the system reliability, a circuit breaker reliability model based on the energy not supplied index (ENS) is proposed.Parameter analysis of non-coherence components caused by the circuit breaker is presented based on the ENS index, which consists of reliability parameters of circuit breaker and other components, loads and system structure. Case studies shows non-coherence phenomenon can be influenced by all this factors. This conclusion is agree with the one received by the qualitative analysis.The characters of non-coherence phenomenon are analyzed based on different reliability index. Case study shows different non-coherence identification results can be reached based on different system reliability index. Study shows non-coherence phenomenon can probable exist in DPS. Analysis on non-coherence components will improve the reliability of DPS while cutting down the cost.This thesis was supported by the National Natural Science Foundation of China (“Study on the reliability non-coherence theory and application for power system”, No. 50777072).更多还原