110kV电容式电压互感器谐波测量特性试验及仿真

Harmonic Measurement Characteristics of Capacitor Voltage Transformer(CVT) of 110 kV

针对电容式电压互感器(capacitor voltage transformers,CVT)测量谐波时从一次回路到二次回路非线性传递的运行特性,从现场试验和软件仿真两方面对CVT谐波测量特性进行研究。以某型号110 kV CVT为研究对象,综合考虑杂散电容、耦合电容、电容分压器介质损耗以及补偿电抗器等效电阻,构建CVT高频等效电路。运用Matlab搭建CVT谐波模型,获得CVT幅频特性曲线。在现场开展谐波测量试验,通过试验结果与仿真结果对比证明仿真模型正确性。最后,通过仿真模型验证谐波电压含量和基波电压幅值对CVT谐波测量特性并无影响。

Considering the harmonic distortion from the primary circuit to the secondary circuit of capacitor voltage transformers （CVT）, the harmonic measurement characteristics of CVT are analyzed with testing and the simulations. By taking a certain type of 110 kV CVT for case study, a high frequency equivalent circuit of CVT is constructed, which takes consideration of stray capacitance, coupling capacitor, dielectric loss of capacitive divider and equivalent resistance of compensation reactor. By using Matlab, the CVT＇ s harmonic model is built and its amplitude-frequency characteristic curves are obtained. To prove the correctness of the simulation model, harmonic measurement tests are carried out for CVT in the field, and the testing results are compared with the simulation results. It is concluded that the voltage harmonic content and the amplitude of the fundamental voltage have no impacts on the measurement characteristics of CVT. This work is supported by Science and Technology Program of State Grid Corpration of China （KJ2012-112）.