摘要
以Dy0型牵引变电所用变压器为例,建立该变压器非同期空载合闸等效电路,分析过电压和励磁涌流的产生机理,并利用电磁暂态仿真软件PSCAD仿真研究变压器非同期合闸时的电磁暂态。结果表明:非同期合闸时的过电压由稳态分量和暂态分量决定,而稳态分量由牵引供电系统的参数决定,暂态分量由合闸时电压向量的合闸角决定;当两相合闸角为90°时,最大过电压为额定电压的1.98倍,基本无励磁涌流;当A相合闸角为0°或180°,且B相未合闸时,变压器不饱和磁通增加,导致未合闸相的电压及励磁电流陡增,最大过电压为额定电压的4.37倍,最大励磁涌流为额定励磁电流的184.5倍,形成严重的励磁涌流;提出采用中间继电器实现两单相断路器同期合闸、在断路器上装设选相合闸装置以及串入合闸电阻以抑制合闸电磁暂态等解决方案。
Taking Dy0-type traction substation used transformer as example,the equivalent circuit of the transformer at asynchronous no-load closing was built to analyze the generation mechanisms of overvoltage and inrush current.The electromagnetic transient simulation software PSCAD was used to study the electromagnetic transient of transformer at asynchronous breaker closing.The results show that overvoltage at asynchronous breaker closing is determined by steady component and transient component.The steady component is determined by the parameters of traction power supply system and the transient component is determined by the closing angle of voltage vector.When the two-phase closing angle is 90°,the maximum overvoltage is 1.98 times of the rated voltage and basically there is no inrush current.When the closing angle of A-phase is 0°or 180°and B-phase is not closed,the unsaturated flux of transformer increases and leads to the sudden increase of voltage and excitation current in phase B.The maximum overvoltage is 4.37 times of the rated voltage and the maximum inrush current is 184.5times of the rated excitation current,which results in serious inrush current.Solutions are proposed,such as,intermediate relay for the synchronous closing of two single-phase circuit breakers,installation of phase selection device in circuit breaker,a series of closing resistance to suppress the electromagnetic transient at breaker closing and so on.
出处
《中国铁道科学》
EI
CAS
CSCD
北大核心
2016年第2期78-84,共7页
China Railway Science
基金
中央高校基本科研业务费专项资金资助项目(2015JBM085)
关键词
牵引变电所
变压器
非同期合闸
过电压
励磁涌流
供电安全
Traction substation
Transformer
Asynchronous breaker closing
Overvoltage
Inrush current
Power supply safety
