引用本文: | 徐波,童悦.基于虚拟仪器的高准确度电子式电流互感器
模拟输出校验系统[J].电力自动化设备,2011,31(2): |
| XU Bo,TONG Yue.High-precision ECT calibration system based on virtual instrument technology[J].Electric Power Automation Equipment,2011,31(2): |
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摘要: |
根据测量用电子式电流互感器(ECT)的校验要求,研制了一种基于虚拟仪器的ECT模拟输出校验系统。介绍了该校验系统的整体构成,针对IEC标准规定的ECT测量通道正常工作频率范围即49.5~50.5 Hz,研究了工作频率变化对信号提取的影响。采用4阶三角卷积窗的FFT算法来提取被校验的信号,与IEC60044-8(ECT)中推荐的FFT算法相比,该算法可以有效减少因非整周期采样造成的频谱泄漏误差,具有更高的准确度。实验表明:当频率波动范围为50 ± 0.5 Hz以内时,校验系统比差可达到10- 4,角差可达到10-2分,满足0.2 S级ECT的校验要求。 |
关键词: ECT 模拟输出 校验系统 IEC FFT |
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基金项目:南京工程学院科研基金资助项目 |
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High-precision ECT calibration system based on virtual instrument technology |
XU Bo1, TONG Yue2
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1.Nanjing Institute of Technology,Nanjing 211167,China;2.Huazhong University of Science of Technology,Wuhan 430074,China
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Abstract: |
An ECT(Electronic Current Transducer) calibration system is designed based on virtual instrument technology to test the analog output of high-precision ECT. Its overall structure is introduced and the influence of frequency variation on signal extraction is analyzed for the normal working frequency range of ECT measurement channel,i.e. 49.5 ~ 50.5 Hz,stipulated by IEC. The fourth-order triangle convolution window algorithm is used to extract the signal detected. Compared with FFT(Fast Fourier Transform) recommended by IEC60044-8(ECT),it reduces the leakage effect error of non-integer-period sampling,resulting in higher accuracy. Experiment shows that,when the frequency deviation is within 50 ± 0.5 Hz,the ratio error reaches the order of 10- 4 and the phase error reaches the order of 10- 2 minutes,meeting the calibration demand of 0.2 S class ECT. |
Key words: electronic current transducer analog output calibration system IEC FFT |