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1

An on-site calibration system for electronic instrument transformers based on LabVIEW

Zhang M., Li K., Wang J., He S.

Metrology and Measurement Systems

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2014

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Vol. 21, nr 2

257--270

EN

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.

2

Highly accurate calibration system for electronic instrument transformers

Tong Y., Ye G., Guo K., Li H.

Metrology and Measurement Systems

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2011

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Vol. 18, nr 2

315-322

EN

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 š0.5 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.

3

Przekładniki elektroniczne - układy i parametry

Nowicz R.

Przegląd Elektrotechniczny

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2003

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R. 79, nr 7-8

511-513

PL

Przekładniki elektroniczne napięciowe i prądowe są wprowadzane w coraz większym stopniu w układach pomiarowych i zabezpieczeniowych, szczególnie dla najwyższych napięć. W artykule omówiono najważniejsze elementy schematu blokowego przekładnika elektronicznego oraz przedstawiono niektóre parametry charakteryzujące te elementy. Zdefiniowano wielkości znamionowe przekładników elektronicznych oraz podano znormalizowane wartości wielkości obwodów wtórnych.

EN

More and more often, electronic current transformers and voltage transducers are introducing into practice for use with electrical measuring instruments and electrical protective devices, especially in HV systems. In the paper, the most important components of a general block diagram of electronic instrument transformers and its specification have been described. The ratings of electronic instrument transducers and rated values of secondary converters have also been presented.