为确保含四绕组变压器的变电站保护整定可靠性,需研究精细化的四绕组变压器暂态模型及其短路计算等值电路。分析常规变压器等值电路的不足,推导了修正的耦合漏感等值电路,根据三相三柱式四绕组变压器的拓扑结构,运用对偶性原理建立了基...为确保含四绕组变压器的变电站保护整定可靠性,需研究精细化的四绕组变压器暂态模型及其短路计算等值电路。分析常规变压器等值电路的不足,推导了修正的耦合漏感等值电路,根据三相三柱式四绕组变压器的拓扑结构,运用对偶性原理建立了基于耦合漏感的四绕组变压器电路-磁路暂态模型;利用漏磁路的互阻抗远小于漏阻抗的特点,推导了用于短路计算的四绕组变压器简化等值电路以及零序阻抗。根据某地220 k V变电站实例进行仿真计算,结果表明所提出的四绕组变压器暂态模型及短路计算方法能够更准确地计算含四绕组变压器变电站的短路电流。展开更多
For studying the coupling effect of electromagnetic irradiation to rectangular enclosure with wire penetration,a new hybrid model is proposed to determine the shielding effectiveness of the enclosure.This model based ...For studying the coupling effect of electromagnetic irradiation to rectangular enclosure with wire penetration,a new hybrid model is proposed to determine the shielding effectiveness of the enclosure.This model based on rectangular-enclosure equivalent circuit regards the penetrating wire as a monopole antenna,and the frequency-domain results of calculation using this model match with that of computer simulation technology(CST)Microwave Studio.Meanwhile,this new model requires far less computation than traditional methods:3 s for one sample on an average personal computer.Based on the presented model,the relationships between enclosure volume,external length of wire penetration,internal length of wire penetration,and shielding effectiveness are analyzed.In the frequency range from 100 MHz to1 000 MHz,when keeping the length of penetrating wire unchanged,the shielding effectiveness of an enclosure at its center point increases with the cavity volume.There is no obvious effect from the external length of penetrating wire on the shielding effectiveness.If the external length of a penetrating wire is 8 cm unchanged,the shielding effectiveness of the penetrated enclosure at its center point declines with the increase of internal length of the penetrating wire.展开更多
文摘为确保含四绕组变压器的变电站保护整定可靠性,需研究精细化的四绕组变压器暂态模型及其短路计算等值电路。分析常规变压器等值电路的不足,推导了修正的耦合漏感等值电路,根据三相三柱式四绕组变压器的拓扑结构,运用对偶性原理建立了基于耦合漏感的四绕组变压器电路-磁路暂态模型;利用漏磁路的互阻抗远小于漏阻抗的特点,推导了用于短路计算的四绕组变压器简化等值电路以及零序阻抗。根据某地220 k V变电站实例进行仿真计算,结果表明所提出的四绕组变压器暂态模型及短路计算方法能够更准确地计算含四绕组变压器变电站的短路电流。
基金Project supported by National Basic Research Program of China(973 Program)Arm Pre-Research Program(51333030101),National Natural Science Foundation of China(61372040)
文摘For studying the coupling effect of electromagnetic irradiation to rectangular enclosure with wire penetration,a new hybrid model is proposed to determine the shielding effectiveness of the enclosure.This model based on rectangular-enclosure equivalent circuit regards the penetrating wire as a monopole antenna,and the frequency-domain results of calculation using this model match with that of computer simulation technology(CST)Microwave Studio.Meanwhile,this new model requires far less computation than traditional methods:3 s for one sample on an average personal computer.Based on the presented model,the relationships between enclosure volume,external length of wire penetration,internal length of wire penetration,and shielding effectiveness are analyzed.In the frequency range from 100 MHz to1 000 MHz,when keeping the length of penetrating wire unchanged,the shielding effectiveness of an enclosure at its center point increases with the cavity volume.There is no obvious effect from the external length of penetrating wire on the shielding effectiveness.If the external length of a penetrating wire is 8 cm unchanged,the shielding effectiveness of the penetrated enclosure at its center point declines with the increase of internal length of the penetrating wire.
