电网发生故障时,故障信号主要包括开关量和电气量。开关量是继电保护的动作信息,目前的故障诊断方法主要基于开关量;电气量是各种故障暂态信息,它蕴含了故障的特征信息,但很少应用于电网故障诊断。提出一种基于改进D-S证据理论的多数据...电网发生故障时,故障信号主要包括开关量和电气量。开关量是继电保护的动作信息,目前的故障诊断方法主要基于开关量;电气量是各种故障暂态信息,它蕴含了故障的特征信息,但很少应用于电网故障诊断。提出一种基于改进D-S证据理论的多数据源信息融合故障诊断方法(information fusion of multi-data resources in fault diagnosis based on improved D-S theory,IMFD),首先对故障信息进行特征提取,通过模糊Petri网将开关量转化为元件的模糊故障度;利用小波变换分析电气量,得到元件的小波故障表征。然后基于改进的D-S证据理论进行信息融合,最后采用C-均值法决策故障元件。仿真计算表明,该方法将电气量和开关量进行信息融合,得到精确的故障诊断结果,在电网故障诊断中有良好的应用前景。展开更多
Fault detection technique is introduced with similarity measure. The characteristics of conventional similarity measure based on fuzzy number are discussed. With the help of distance measure, similarity measure is con...Fault detection technique is introduced with similarity measure. The characteristics of conventional similarity measure based on fuzzy number are discussed. With the help of distance measure, similarity measure is constructed explicitly. The designed distance-based similarity measure is applicable to general fuzzy membership functions including non-convex fuzzy membership function, whereas fuzzy number-based similarity measure has limitation to calculate the similarity of general fuzzy membership functions. The applicability of the proposed similarity measure to general fuzzy membership structures is proven by identifying the definition. To decide fault detection of flight system, the experimental data （pitching moment coefficients and lift coefficients） are transformed into fuzzy membership functions. Distance-based similarity measure is applied to the obtained fuzzy membership functions, and similarity computation and analysis are obtained with the fault and normal operation coefficients.展开更多
文摘电网发生故障时,故障信号主要包括开关量和电气量。开关量是继电保护的动作信息,目前的故障诊断方法主要基于开关量;电气量是各种故障暂态信息,它蕴含了故障的特征信息,但很少应用于电网故障诊断。提出一种基于改进D-S证据理论的多数据源信息融合故障诊断方法(information fusion of multi-data resources in fault diagnosis based on improved D-S theory,IMFD),首先对故障信息进行特征提取,通过模糊Petri网将开关量转化为元件的模糊故障度;利用小波变换分析电气量,得到元件的小波故障表征。然后基于改进的D-S证据理论进行信息融合,最后采用C-均值法决策故障元件。仿真计算表明,该方法将电气量和开关量进行信息融合,得到精确的故障诊断结果,在电网故障诊断中有良好的应用前景。
基金Project supported by the Second Stage of Brain Korea and Korea Research Foundation
文摘Fault detection technique is introduced with similarity measure. The characteristics of conventional similarity measure based on fuzzy number are discussed. With the help of distance measure, similarity measure is constructed explicitly. The designed distance-based similarity measure is applicable to general fuzzy membership functions including non-convex fuzzy membership function, whereas fuzzy number-based similarity measure has limitation to calculate the similarity of general fuzzy membership functions. The applicability of the proposed similarity measure to general fuzzy membership structures is proven by identifying the definition. To decide fault detection of flight system, the experimental data （pitching moment coefficients and lift coefficients） are transformed into fuzzy membership functions. Distance-based similarity measure is applied to the obtained fuzzy membership functions, and similarity computation and analysis are obtained with the fault and normal operation coefficients.
