电容式电压互感器的谐波传递特性研究  

Harmonic Transfer Characteristic of Capacitor Voltage Transformer

作　　者：郜洪亮[1] 李琼林[1] 余晓鹏[1] 张振安[1] 代双寅[1] 刘书铭[1] 

机构地区：[1]国网河南省电力公司电力科学研究院,河南省郑州市450052

出　　处：《电网技术》2013年第11期3125-3130,共6页Power System Technology

基　　金：国家电网公司科技项目(SG11113)~~

摘　　要：针对电容式电压互感器(capacitor voltage transformer,CVT)的谐波传递特性,综合考虑杂散电容等因素影响,建立等效电路模型,采用逐级计算各级等效阻抗和传递函数的方法,对CVT谐波传递特性进行深入计算和分析。基于Matlab/Simulink仿真工具对CVT谐波传递特性开展了仿真验证,并针对实际CVT开展了CVT谐波传递特性和测量误差的实际物理试验研究,试验结果与仿真分析结果具有较好的一致性。发现影响CVT谐波传递特性的因素不仅是LC串联谐振回路额定工作点的偏移,中间变压器一次侧和补偿电抗器的杂散电容对CVT谐波传递特性有着重要影响,传递函数幅频特性曲线呈现尖峰和低谷效应,导致较大的测量误差。Synthetically considering the impacts of such factors as stray capacitance and so on, an equivalent circuit model of harmonic transfer characteristic of capacitor voltage transformer （CVT） is established, based on this model and in the manner of stepwise calculating equivalent impedances and transfer functions of different orders in the established model, the harmonic transfer characteristic of CVT is calculated and analyzed in depth. Based on Matlab/Simulink the simulative verification of the harmonic transfer characteristic of CVT is performed, and based on actual CVT the practical physical experiment and research on the harmonic transfer characteristic of CVT and the measuring error are carried out, and there is a better consistency between results from experiments and simulative analysis. It is found out that not only the working point deviation of series resonant circuit is the factor impacting the harmonic transfer characteristic of CVT, but also the stray capacitance at primary side of the intermediate transformer and the stray capacitance of compensation reactor greatly affect the harmonic transfer characteristic of CVT, and they make the amplitude-versus-frequency curve of the transfer function appearing spike effect and valley effect and lead to a larger measuring error.

关 键 词：电容式电压互感器 谐波 传递函数 频率特性 测量误差 串联谐振 杂散电容 

分 类 号：TM45[电气工程—电器]