中文摘要：

由于网络结构、负荷水平、元件可靠性等因素的影响，电力系统中可能存在可靠性非同调元件。退出非同调元件，系统可靠性不但没有降低反而得到改善。通过辨识可靠性非同调元件，可有效降低电力元件对系统可靠性的负面影响，提高资金的使用效率。为此，给出了多回并行线路的可靠性解析模型，推导非同调元件的辨识模型，即由系统参数可直接辨识某元件是否非同调元件，而不需计算可靠性指标；同时还提出了非同调概率、频率及非同调时间等新指标用以描述系统的可靠性非同调程度。分析3回并行线路的结果表明，负荷水平和元件可靠性参数是影响系统非同调特性的重要因素，当负荷大于非同调临界负荷时，系统同调，反之系统非同调，负荷越小，非同调特性越显著；但元件可靠性参数的变化会改变系统可靠性非同调临界负荷。

英文摘要：

Reliability non-coherence components （RNCs） may exist in a power system due to the effects of network configuration, load level, component reliability performance and other factors. In a reliability non-coherence power system, the system reliability will not be deteriorated or even become better when a component is out of service or is removed from the original system. Recognizing the RNCs of a power system can effectively reduce the component＇s negative impact on the system reliability and improve the capital benefit. We proposed a non-coherence component identification model for multiple parallel transmission lines, which could directly be used to recognize the non coherence components without evaluating the system reliability. In order to describe the degree of the system reliability non-coherence feature, we also proposed the reliability non-coherence probability, frequency and energy indices. Moreover, case studies of three multiple parallel transmission lines were conducted. The results show that load level and components＇ reliability parameters have an important effect on the reliability non coherence feature. The system is a coherence system when load is larger than the non-coherence threshold load; otherwise, the system is non-co- herence. Smaller the load is, more significant the non-coherence feature is. However, the system non-coherence threshold load will change with components＇ reliability parameters.