• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.9
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• pp.470-474
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• 2004

Both ratio error and phase angle error in voltage transformer(VT) depend on values of burden of VT used. A method of evaluation for linearity of ratio error and phase angle error in VT measurement equipment have been developed using the standard resistance burdens, with negligible AC-DC resistance difference less than $10^-6$. These burden consists of five standard resistors, with nominal resistance of 100 $\Omega$, 1 k$\Omega$, 10 k$\Omega$, 100 k$\Omega$, and 1 M$\Omega$. The developed method has been applied in VT measurement equipment of industry and the validity of the developed method has been verified by showing the consistency of the result of linearity obtained using VT with wide ratio error.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.2
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• pp.66-70
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• 2005

Linearity of ratio error of instrument transformer comparator has been tested using wide ratio error voltage transformer(VT) with the ratio errors in the range of -3 ％ to 3 ％. The technique is the method for evaluation of the linearity for instrument transformer comparator by comparing both the theoretical and experimental values in wide ratio error VT. The developed method has been successfully applied for calibration and correction in instrument transformer comparator belonging to industry.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.6
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• pp.274-278
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• 2005

Voltage transformer(VT) comparison measurement system is usually used for measurements of ratio error and phase angle error of VT made in industry. Both ratio error and phase angle error in VT are critically influenced by values of burden of VT used. External burden effects on both ratio error and phase angle error in VT are theoretically calculated. From the theoretical calculation, a method of evaluation for linearity of ratio error and phase angle error in VT measurement system have been developed using the standard capacitive burdens, with negligible dissipation factor less than 10$^{-4}$. These burden consists of five standard capacitors, with nominal capacitance of 1.1 $\mu$F, 1 $\mu$F, 0.1 $\mu$F, 0.01 $\mu$F, 0.001 $\mu$F. The developed method has been applied in VT measurement system of industry, showing in good consistency and linearity within 0.001 $\%$ between theoretical and measured values.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.6
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• pp.313-316
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• 2006

A method for evaluation of the linearity of both the ratio error and phase angle error in the current transformer(CT) comparison measurement equipment has been developed by employing the standard resistors with negligible AC-DC resistance difference less than $10^{-5}$. The non-reactive standard resistors for the linearity check of the system are used as the external burden connected with the secondary of CT under test. These burdens consist of nine standard resistors, with the nominal resistance of $0.01{\Omega},\;0.1{\Omega},\;0.2{\Omega},\;0.4{\Omega},\;0.6{\Omega},\;1{\Omega},\;2{\Omega},\;4{\Omega}$, and $10{\Omega}$. For linearity check, the developed method has been applied in the CT comparison measurement equipment belonging to the industry.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.6
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• pp.302-307
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• 2006

Standard current transformer(CT) with the nominal ratio errors in the range of - 10 % to + 10 % has been developed. Linearity of the CT ratio error measuring system (CT comparator) has been tested by using wide ratio error standard current transformer(WRE CT). The developed WRE CT can be used to evaluate the linearity of the CT comparator by comparing both the theoretical values and experimental values of the WRE CT. The developed method has been successfully applied for calibration and correction in the CT comparator belonging to industry.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.1
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• pp.50-50
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• 2000

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.1
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• pp.51-56
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• 2000

This paper presents the characteristics of the dynamic response and calibration technique on a linear variable differential transformer(LVDT). The linear error of the LVDT was proven $\pm$1% in the static calibration and $\pm$0.5% in the dynamic calibration. In this paper, the linearity error generated in the static and dynamic state of the core movement can be eliminated using the correction algorithem of the static and dynamic state derived from the least square linear approximation for the nonlinearity of the curves of direct data fitting and Lagrange polynomials. With the static and dynamic calibration method, the calibration accuracy of the LVDT can be reduced to within $\pm{0.5%.}$.

• Journal of the Semiconductor & Display Technology
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• v.3 no.4
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• pp.19-27
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• 2004

The characteristic evaluation of A/D converter is to measure the linearity of the converter. The evaluation of the linearity is to measure the DNL, INL, gain error and offset error in the various test parameters of A/D converter. Generally, DNL and INL are to be measured by the Histogram Test Algorithm in the DSP-based ATE environment. And gain error and offset error are to be measured by the calculation equation of the measuring algorithm. It is to propose the new Concurrent Histogram Test Algorithm for the test of the housekeeping A/D converter used in the CDMA cellular phone. Using the proposed method, it is to measure the DNL, INL, gain error and offset error concurrently and to show the measured results.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.12
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• pp.1019-1025
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• 2003

We introduce a new auto-calibration/simulation method for a strain gage type transducer/signal-conditioner which guarantees the output linearity and compensates the error automatically. We design a micro voltage supply which is able to interface either AC or DC type excitation voltage. A new strain gage simulator is also designed. We make linearity output of the signal conditioner and can compensate error automatically with this new auto calibration/simulation method. The experimental results show that the error between the real value and the expected one is less than 1%.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.6
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• pp.1017-1021
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• 2008

A calculable potential transformer(PT) with nominal ratio error in wide range of -10% to +10% has been developed on basis of theoretical calculation of ratio error by the number of windings. The developed PT can be used to evaluate the linearity and accuracy of the PT comparator by comparing both the theoretical and experimental values of the PT which have exactly same ratio errors in nominal and calculated values. The PT has been applied for calibration and correction of the PT comparator up to wide ratio error range of -10% to +10%. This portable PT is very convenient to carry to the power industry for the on-site calibration of the PT comparator.