基于电压互感器非线性宽频模型的宽频电压测量

Wideband Voltage Measurement Based on Nonlinear Wideband Model of Potential Transformer

摘要:

宽频暂态电压测量有望在未来的电力系统中得到广泛的应用。电力系统广泛配置宽频暂态测量的最具技术和经济效益的方法之一是升级现有的电压互感器，使其具有宽频暂态测量能力。针对电磁式电压互感器（potential transformer，PT），提出了一种基于宽频模型和算法的技术，该技术涉及 PT 的非线性特征和宽频线性，使 PT 具有宽频暂态电压测量能力，方法包括建立非线性宽频模型的方法和基于输出电压的逆计算方法，以恢复输入电压波形。并详细介绍了 PT 等效电路模型的综合方法，同时，给出了基于电路理论和储能元件及非线性元件的等效方法，以及基于电路模型的逆计算方法。以雷电冲击为验证源，对 10 kV PT 进行了验证实验。实验结果与标准器记录的输入波形匹配良好。

Abstract:

Wideband transient voltage measurement is expected to be widely applied in future power systems. One of the methods with the most technical and economical benefits for widely-equipped wideband transient measurement in power system is to upgrade the existing potential transformers (PT) to be enabled with wideband transient measurement. A method based on wide-band models and algorithms is proposed for electromagnetic voltage transformers, which involves the nonlinear characteristics and wideband linearity of PT, enabling PT to have the capabilities of wideband transient voltage measurement. The methods include the establishment of a nonlinear wideband model and an inverse calculation method based on output voltage to recover the input voltage waveform. The comprehensive method of PT equivalent circuit model is introduced in detail, and the equivalence method based on circuit theory, energy storage components and nonlinear components is given, as well as an inverse calculation method based on the entire model. A verification experiment is conducted on 10 kV PT taking lightning impulse as the verification source. The experimental results match well with the input waveform recorded by the standard device.