The Fault Signal Extraction Research in the Electric Power Metering System

Abstract:

On the basis of the resistance model of high voltage electric power metering system, we make a study on the saturation of the measuring CT when the load is heavy. Through experiments on measuring current transformers, we chose high-quality power frequency magnetic core of the least saturation. On the secondary side of the measuring CT, circuit debugging was carried on and through experiments, optimal circuit parameters were determined to optimize the detection circuit which reduced the resistance of the secondary side of the measuring CT to the utmost to decrease the magnetic flux in the magnetic core to weaken saturation. Through FIR filter we extract detection signal from the fault signal to diagnose the fault. The practical test show the extracted detection signal can accurately judge the fault.

• Periodical: Applied Mechanics and Materials (Volume 743)
• Pages: 555-559
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.743.555
• Online since: March 2015
• Authors: J.J. Zhao, Wei Liang, H.J. Ge
• Keywords: Current Transformer, Fault Detection, Fault Signal, FIR Filter, High Voltage Electric Power

References

[1] Xinhua Chen, Lijuan Jiang. Classification of electric measuring instruments & brief introduction of measuring ways. Electrical Measurement &Instrumentation, 41(457), 4-6, (2004).

[2] Jianjun Zhao, Sujun Zhang. Fault analysis and modeling for the high voltage electric power metering system. Electrical Measurement &Instrumentation, 44(4), 5-8, (2007).

[3] Jianjun Zhao, Haijian Ge, Hui Jia. The fault information extraction research in the electric power measurement system based on the wavelet transform. Journal of Henan Universiy(Natural Science), 42(5), 641-645, (2012).

[4] Jianjun Zhao, Wei Liang, Yueyang Zhang. Design of fault detecting circuits for high voltage electric power metering system. Journal of Henan Universiy(Natural Science), 44(1), 25-29, (2014).

[5] Lei Yu. Research on core saturation characteristics of current transformer. Journal of Shenyang Institute of Engineering(Natural Science), 5(4), 340-343, (2009).

[6] Guangshu Hu. Digital signal processing. second ed, Tsinghua University, Beijing, (2003).

[7] McClellan J H, Parks T W. A unified approach to the design of optimum FIR linear phase digital filters. IEEE Transactions on Circuit Theory, 20(6), 697-701, (1973).

DOI: 10.1109/tct.1973.1083764

[8] Minge Chen, Zhanya Jiao, Xiaogang An. A method of designing of equiripple linear-phase FIR filter. Journal of xi'an university of science and technology, 28(1), 199-200, (2008).