Single-phase 25 kV traction networks of electrified alternating current(AC)railways create electromagnetic fields(EMFs)with significant levels of intensity.The most intense magnetic fields occur when short circuits ex...Single-phase 25 kV traction networks of electrified alternating current(AC)railways create electromagnetic fields(EMFs)with significant levels of intensity.The most intense magnetic fields occur when short circuits exist between the contact wire and rails or ground.Despite the short duration of exposure,they can adversely affect electronic devices and induce significant voltages in adjacent power lines,which is dangerous for operating personnel.Although numerous investigations have focused on modeling the EMF of traction networks and power lines,the challenge of determining the three-dimensional electromagnetic fields near metal supports during the flow of a short-circuit current through them is yet to be resolved.In this case,the field has a complex spatial structure that significantly complicates the calculations of intensities.This study proposes a methodology,algorithms,software,and digital models for determining the EMF in the described emergency scenarios.During the modeling process,the objects being studied were represented by segments of thin wires to analyze the distribution of the electric charge and calculate the intensities of the electric and magnetic fields.This approach was implemented in the Fazonord software,and the modeling results show a substantial increase in EMF levels close to the support,with a noticeable decrease in the levels as the distance from it increases.The procedure implemented in the commercial software Fazonord is universal and can be used to determine electromagnetic fields at any electrical power facility that includes live parts of limited length.Based on the proposed procedure,the EMF near the supports of overhead power lines and traction networks of various designs could be determined,the EMF levels at substations can be calculated,and the influence of metal structures located near traction networks,such as pedestrian crossings at railway stations,can be considered.展开更多
本文指出现代高层建筑、超高层建筑兴起发展背景下,建筑内部普遍覆盖有多类电气产品,不同产品应用方向和参数存在差异,应急照明电源(Emergency Power Supply,EPS)能够有效提升建筑供配电设计中照明系统的智能性、稳定性。本文分析了建...本文指出现代高层建筑、超高层建筑兴起发展背景下,建筑内部普遍覆盖有多类电气产品,不同产品应用方向和参数存在差异,应急照明电源(Emergency Power Supply,EPS)能够有效提升建筑供配电设计中照明系统的智能性、稳定性。本文分析了建筑工程供配电设计中应急照明电源EPS的运用现状、优势特征,系统性总结阐述了建筑工程供配电系统设计中应急照明电源EPS的运用方法、容量计算方法,通过实际案例为EPS配置计算作了引用论述,并就EPS常见维护问题进行了综合论述,旨在进一步完善建筑工程供配电设计中EPS运用研究理论依据,为相关工作提供参考。展开更多
APF-EPS系统在APF(Active Power Filter)有源滤波器的主框架上构建EPS(Emergency Power Supply),实现应急供电系统的自动化管理。系统在保证供电电能质量的同时,按需要提供紧急备用供电电源。APF-EPS系统,合理考虑了APF和EPS在使用时间...APF-EPS系统在APF(Active Power Filter)有源滤波器的主框架上构建EPS(Emergency Power Supply),实现应急供电系统的自动化管理。系统在保证供电电能质量的同时,按需要提供紧急备用供电电源。APF-EPS系统,合理考虑了APF和EPS在使用时间上和性能结构上的互补性,不仅节约硬件成本,更能合理有效地协调APF和EPS,增强了系统的实用性。给出了APF-EPS系统的构建框架,并进行了仿真分析。展开更多
详细分析了双电源自动切换装置及不间断电源(uninterruptible power supply,UPS)、紧急电力供给(emergencypower supply,EPS)装置在上海世博会非洲联合馆保电工作中的应用。在今后重大活动的保电工作中,可以借鉴非洲联合馆的成功运行经...详细分析了双电源自动切换装置及不间断电源(uninterruptible power supply,UPS)、紧急电力供给(emergencypower supply,EPS)装置在上海世博会非洲联合馆保电工作中的应用。在今后重大活动的保电工作中,可以借鉴非洲联合馆的成功运行经验,确保重要负荷电力可靠供应。展开更多
针对应急电源带非线性负载时存在波形畸变和负载切换动态性能差等问题,通过对系统带有不同负载传递函数的分析,提出了模糊自整定PI控制与三闭环控制相结合的复合控制策略。通过系统仿真,将该复合控制策略应用于DSP(Digital Signal Proce...针对应急电源带非线性负载时存在波形畸变和负载切换动态性能差等问题,通过对系统带有不同负载传递函数的分析,提出了模糊自整定PI控制与三闭环控制相结合的复合控制策略。通过系统仿真,将该复合控制策略应用于DSP(Digital Signal Processing)控制的1 k W应急电源样机上。实验结果表明,该控制策略具有良好的动态性能和较强的谐波抑制能力。展开更多
针对目前EPS(Emergency Power Supply,EPS)应急电源切换速度慢的问题,提出了一种快速切换的单相应急电源的数字化解决方案。基于锁相原理,令EPS输出电压和市电电压的大小、频率、相位保持一致,用DSP实现了EPS的快速切换技术,同时提出了...针对目前EPS(Emergency Power Supply,EPS)应急电源切换速度慢的问题,提出了一种快速切换的单相应急电源的数字化解决方案。基于锁相原理,令EPS输出电压和市电电压的大小、频率、相位保持一致,用DSP实现了EPS的快速切换技术,同时提出了一种简单的蓄电池在线监测系统硬件实现方式。并设计了一台50Hz,220V/1.5kVA的EPS应急电源,采用继电器切换,从市电出现异常时刻开始到切换完成时刻止,切换时间小于10ms。展开更多
文摘Single-phase 25 kV traction networks of electrified alternating current(AC)railways create electromagnetic fields(EMFs)with significant levels of intensity.The most intense magnetic fields occur when short circuits exist between the contact wire and rails or ground.Despite the short duration of exposure,they can adversely affect electronic devices and induce significant voltages in adjacent power lines,which is dangerous for operating personnel.Although numerous investigations have focused on modeling the EMF of traction networks and power lines,the challenge of determining the three-dimensional electromagnetic fields near metal supports during the flow of a short-circuit current through them is yet to be resolved.In this case,the field has a complex spatial structure that significantly complicates the calculations of intensities.This study proposes a methodology,algorithms,software,and digital models for determining the EMF in the described emergency scenarios.During the modeling process,the objects being studied were represented by segments of thin wires to analyze the distribution of the electric charge and calculate the intensities of the electric and magnetic fields.This approach was implemented in the Fazonord software,and the modeling results show a substantial increase in EMF levels close to the support,with a noticeable decrease in the levels as the distance from it increases.The procedure implemented in the commercial software Fazonord is universal and can be used to determine electromagnetic fields at any electrical power facility that includes live parts of limited length.Based on the proposed procedure,the EMF near the supports of overhead power lines and traction networks of various designs could be determined,the EMF levels at substations can be calculated,and the influence of metal structures located near traction networks,such as pedestrian crossings at railway stations,can be considered.
文摘本文指出现代高层建筑、超高层建筑兴起发展背景下,建筑内部普遍覆盖有多类电气产品,不同产品应用方向和参数存在差异,应急照明电源(Emergency Power Supply,EPS)能够有效提升建筑供配电设计中照明系统的智能性、稳定性。本文分析了建筑工程供配电设计中应急照明电源EPS的运用现状、优势特征,系统性总结阐述了建筑工程供配电系统设计中应急照明电源EPS的运用方法、容量计算方法,通过实际案例为EPS配置计算作了引用论述,并就EPS常见维护问题进行了综合论述,旨在进一步完善建筑工程供配电设计中EPS运用研究理论依据,为相关工作提供参考。
文摘APF-EPS系统在APF(Active Power Filter)有源滤波器的主框架上构建EPS(Emergency Power Supply),实现应急供电系统的自动化管理。系统在保证供电电能质量的同时,按需要提供紧急备用供电电源。APF-EPS系统,合理考虑了APF和EPS在使用时间上和性能结构上的互补性,不仅节约硬件成本,更能合理有效地协调APF和EPS,增强了系统的实用性。给出了APF-EPS系统的构建框架,并进行了仿真分析。
文摘详细分析了双电源自动切换装置及不间断电源(uninterruptible power supply,UPS)、紧急电力供给(emergencypower supply,EPS)装置在上海世博会非洲联合馆保电工作中的应用。在今后重大活动的保电工作中,可以借鉴非洲联合馆的成功运行经验,确保重要负荷电力可靠供应。
文摘针对应急电源带非线性负载时存在波形畸变和负载切换动态性能差等问题,通过对系统带有不同负载传递函数的分析,提出了模糊自整定PI控制与三闭环控制相结合的复合控制策略。通过系统仿真,将该复合控制策略应用于DSP(Digital Signal Processing)控制的1 k W应急电源样机上。实验结果表明,该控制策略具有良好的动态性能和较强的谐波抑制能力。
文摘针对目前EPS(Emergency Power Supply,EPS)应急电源切换速度慢的问题,提出了一种快速切换的单相应急电源的数字化解决方案。基于锁相原理,令EPS输出电压和市电电压的大小、频率、相位保持一致,用DSP实现了EPS的快速切换技术,同时提出了一种简单的蓄电池在线监测系统硬件实现方式。并设计了一台50Hz,220V/1.5kVA的EPS应急电源,采用继电器切换,从市电出现异常时刻开始到切换完成时刻止,切换时间小于10ms。
