随着智能电网建设速度加快,为保证电力系统安全稳定运行,对电力系统参量信息进行提取分析的要求越来越高。当前,配电系统中大量配电架空线路电流难以实现非接触式的有效检测。针对此问题,提出了一种基于磁场反演的非接触式三相配电架空...随着智能电网建设速度加快,为保证电力系统安全稳定运行,对电力系统参量信息进行提取分析的要求越来越高。当前,配电系统中大量配电架空线路电流难以实现非接触式的有效检测。针对此问题,提出了一种基于磁场反演的非接触式三相配电架空线路电流检测方法。首先根据磁场逆问题建立线路电流反演寻优模型,继而引入参考点机制的非支配排序遗传算法(non-dominated sorting genetic algorithm,NSGA-Ⅲ)对该模型进行求解,然后结合优劣解距离法(technique for order preference by similarity to ideal solution,TOPSIS)筛选出符合决策者要求的最优解,以此绘制拟合曲线并提取特征参数。最后通过算例分析与试验验证了所提方法的有效性和准确性。展开更多
Abstract Objective Higher levels of exposure to extremely low-frequency magnetic fields （ELF-MF） are associated with a slightly increased risk of childhood leukaemia. Compared with more-developed Western countries, ...Abstract Objective Higher levels of exposure to extremely low-frequency magnetic fields （ELF-MF） are associated with a slightly increased risk of childhood leukaemia. Compared with more-developed Western countries, higher exposure levels are evident in the Czech Republic, probably because of the different types of housing. In light of this, we aimed to examine the association between ELF-MF exposure and childhood leukaemia in the Czech Republic. Methods We conducted a paired case-control study. The cases （children with leukaemia） were age- sex- and permanent residence-matched to controls （children without leukaemia）. Although this limited potential bias and confounding, it also limited our number of participants. Results The matched analyses included 79 case-control pairs. No significant association between ELF-MF exposure and childhood leukaemia was observed for exposures over 0.2 μT （odds ratio [0R]=0.93, confidence interval [Cl]=0.45-1.93）, 0.3 μT （0R=0.77, Cl=0.34-1.75）, or 0.4 μT （OR=0.9, Cl=0.37-2.22）. Conclusion Despite higher levels of exposure in Middle and Eastern Europe, no indication of an association between ELF-MF exposure and childhood leukaemia was determined. This in contrast to the findings of previous studies conducted in different countries.展开更多
文摘随着智能电网建设速度加快,为保证电力系统安全稳定运行,对电力系统参量信息进行提取分析的要求越来越高。当前,配电系统中大量配电架空线路电流难以实现非接触式的有效检测。针对此问题,提出了一种基于磁场反演的非接触式三相配电架空线路电流检测方法。首先根据磁场逆问题建立线路电流反演寻优模型,继而引入参考点机制的非支配排序遗传算法(non-dominated sorting genetic algorithm,NSGA-Ⅲ)对该模型进行求解,然后结合优劣解距离法(technique for order preference by similarity to ideal solution,TOPSIS)筛选出符合决策者要求的最优解,以此绘制拟合曲线并提取特征参数。最后通过算例分析与试验验证了所提方法的有效性和准确性。
文摘Abstract Objective Higher levels of exposure to extremely low-frequency magnetic fields （ELF-MF） are associated with a slightly increased risk of childhood leukaemia. Compared with more-developed Western countries, higher exposure levels are evident in the Czech Republic, probably because of the different types of housing. In light of this, we aimed to examine the association between ELF-MF exposure and childhood leukaemia in the Czech Republic. Methods We conducted a paired case-control study. The cases （children with leukaemia） were age- sex- and permanent residence-matched to controls （children without leukaemia）. Although this limited potential bias and confounding, it also limited our number of participants. Results The matched analyses included 79 case-control pairs. No significant association between ELF-MF exposure and childhood leukaemia was observed for exposures over 0.2 μT （odds ratio [0R]=0.93, confidence interval [Cl]=0.45-1.93）, 0.3 μT （0R=0.77, Cl=0.34-1.75）, or 0.4 μT （OR=0.9, Cl=0.37-2.22）. Conclusion Despite higher levels of exposure in Middle and Eastern Europe, no indication of an association between ELF-MF exposure and childhood leukaemia was determined. This in contrast to the findings of previous studies conducted in different countries.
