Calibration System for Electronic Instrument Transformers with Digital Output

Author(s):  
B. Djokic ◽  
E. So
2014 ◽  
Vol 21 (2) ◽  
pp. 257-270 ◽  
Author(s):  
Ming Zhang ◽  
Kaicheng Li ◽  
Jun Wang ◽  
Shunfan He

Abstract Electronic voltage transformers (EVT) and electronic current transformers (ECT) are important instruments in a digital substation. For simple, rapid and convenient development, the paper proposed an on-site calibration system for electronic instrument transformers based on LabVIEW. In the system, analog signal sampling precision and dynamic range are guaranteed by the Agilent 3458A digital multimeter, and data synchronization is also achieved based on a self-developed PCI synchronization card. To improve the measurement accuracy, an error correction algorithm based on the Hanning window interpolation FFT has good suppression of frequency fluctuation and inter-harmonics interference. The human-computer interface and analysis algorithm are designed based on LabVIEW, and the adaptive communication technology is designed based on IEC61850 9-1/2. The calibration system can take into account pairs of digital output and analog output of the electronic voltage/current transformer calibration. The results of system tests show that the calibration system can meet the requirements of 0.2 class calibration accuracy, and the actual type test and on-site calibration also show that the system is easy to operate with convenience and satisfactory stability.


2011 ◽  
Vol 18 (2) ◽  
pp. 315-322 ◽  
Author(s):  
Yue Tong ◽  
Guoxiong Ye ◽  
Keqin Guo ◽  
Hongbin Li

Highly Accurate Calibration System for Electronic Instrument Transformers A high accurate electronic instrument transformer calibration system is introduced in this paper. The system uses the fourth-order convolution window algorithm for the error calculation method. Compared with Fast Fourier Transform, which is recommended by standard IEC-60044-8 (Electronic current transformers), it has higher accuracy. The relative measuring errors caused by asynchronous sampling could be reduced effectively without any special hardware technique adopted. The results show that the ratio error caused by asynchronous sampling can be reduced to 10-4, and the phase error can be reduced to 10-3 degrees when the deviation of frequency is within ±0.5 Hz. The present method of measurement processing is achieved by a high-accuracy USB multifunction data acquisition (DAQ) card and virtual measurement devices, with low cost, short exploitation period and high stability.


IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 97614-97623 ◽  
Author(s):  
Zhenhua Li ◽  
Yawei Du ◽  
A. Abu-Siada ◽  
Zhenxing Li ◽  
Tao Zhang

2014 ◽  
Vol 36 (6) ◽  
pp. 734-742 ◽  
Author(s):  
Zhenhua Li ◽  
Hongbin Li ◽  
Zhi Zhang ◽  
Pandian Luo ◽  
Hongfeng Li ◽  
...  

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 4061
Author(s):  
Alessandro Mingotti ◽  
Lorenzo Peretto ◽  
Roberto Tinarelli

The scenario of instrument transformers has radically changed from the introduction of the Low-Power version, both passive and active. The latter type, typically referred to as Electronic Instrument Transformers (EITs), has no dedicated standard within the IEC 61869 series yet. To this purpose, in the authors’ opinion, it is worth understanding how the limits of typical disturbances affecting EITs should be standardized. In particular, after a brief review of the standards, the work presented a mathematical approach to determine the sources of signal disturbances influence, which affect the rms value, on the ratio error. From the results, we discussed that the emergence of disturbances generated within the EIT is a critical aspect to be studied with data of typical off-the-shelf devices. Therefore, to guarantee a correct operation of the devices, a proper standardization of the sources of disturbance should be provided.


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