摘要
牵引供电系统中,常发生因机车谐波电流注入与牵引供电系统谐振点频率相匹配,出现严重的谐波谐振问题。阻抗特性能精确反映出系统谐振点,因此急需发展频域阻抗测量技术。该文基于谐波激励方式,提出一种可控测量频带的牵引供电系统频域阻抗测量方法。利用鸟鸣脉宽调制信号(chirp pulse width modulation,chirp-PWM)驱动大功率谐波激励电路,只需一次扰动实验便能在牵引供电系统中产生所设定频带内的宽频谐波激励,根据响应电压、电流信息可计算获取设定频带内的阻抗信息。此方法充分减小传统基于扫频法测量阻抗的测量时间,且谐波激励电路结构简单,控制信号易于得到,测量频带可控。可为开发牵引供电系统频域阻抗测量装置提供重要参考。
Harmonic resonance has frequently occurred in electric railway systems due to the match between injected harmonic currents and system resonance points.Impedance characteristic can accurately reflect the system resonance point,thus the accurate impedance measurement for electric railway is needed.This paper proposed a method for measuring the broadband impedance of traction power system at controlled frequency band based on active harmonic excitation.A chirp pulse width modulation(chirp-PWM)signal was adopted to drive the large-power harmonic excitation circuit,and the harmonic excitation at controlled frequency band can be obtained by only once disturbance.Then,the impedance at controlled frequency band can be calculated according to the response voltage and current.This method has less measurement time compared with the traditional frequencysweeping method.Meanwhile,the structure of harmonic excitation circuit is simple and the control signal can be obtained easily.The measurement is more flexible due that the measured frequency band can be controlled,which can be an important reference for designing the impedance measurement equipment of traction network.
作者
潘鹏宇
宋依桐
何正友
PAN Pengyu;SONG Yitong;HE Zhengyou(School of Electrical Engineering,Southwest Jiaotong University,Chengdu 610031,Sichuan Province,China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2019年第18期5399-5405,5587,共8页
Proceedings of the CSEE
基金
国家重点研发计划项目(2017YFB1200802)
国家自然科学基金项目(51677154)~~
关键词
阻抗测量
牵引供电系统
谐波谐振
可控频带谐波激励
稳定性分析
impedance measurement
electric railway system
harmonic resonance
harmonic excitation at controlled frequency band
stability analysis
