Studying the Effect of Stray Capacitance on the Measurement Accuracy of the CVT Based on the Boundary Element Method

The capacitive voltage transformer (CVT) is a special measuring and protecting device, which is commonly applied in high-voltage power systems. Its measurement accuracy is affected seriously by the stray capacitances of the capacitance voltage divider (CVD) to ground and other charged parts. In this...

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Main Authors: Chuan Xiang, Xinwei Chen, Hongge Zhao, Zejun Ren, Guoqing Zhao
Format: Article
Language:English
Published: Wiley 2021-01-01
Series:Complexity
Online Access:http://dx.doi.org/10.1155/2021/1155443
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author Chuan Xiang
Xinwei Chen
Hongge Zhao
Zejun Ren
Guoqing Zhao
author_facet Chuan Xiang
Xinwei Chen
Hongge Zhao
Zejun Ren
Guoqing Zhao
author_sort Chuan Xiang
collection DOAJ
description The capacitive voltage transformer (CVT) is a special measuring and protecting device, which is commonly applied in high-voltage power systems. Its measurement accuracy is affected seriously by the stray capacitances of the capacitance voltage divider (CVD) to ground and other charged parts. In this study, based on the boundary element method, a mathematical model was established firstly to calculate the stray capacitance. Then, the voltage distribution of the CVD was obtained by the CVD’s equivalent circuit model. Next, the effect of stray capacitance on the voltage distribution and the voltage difference ratio (VDR) of CVD was analysed in detail. We finally designed three types of shield and optimized their structure parameters to reduce VDR. The results indicated that the average deviation rate between calculated and experimental measured voltages is only 0.015%; that is to say, the method has high calculation precision. The stray capacitance of the CVD to ground is far larger than that of the CVD to the high-voltage terminal. It results in the inhomogeneous distribution of voltage and the increase of VDR. For the test CVT, its VDR exceeds the requirement of class 0.2. Among all of the three types of shield, the C type reduced the VDR of the test CVT the most. After optimizing the structure parameters of C-type shield, the VDR is further reduced to 0.08%. It is not only in accord with the requirement of class 0.2 but also has an adequate margin.
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language English
publishDate 2021-01-01
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spelling doaj-art-aeed5b175b194b88997935c607fa8bcc2025-08-20T02:23:08ZengWileyComplexity1076-27871099-05262021-01-01202110.1155/2021/11554431155443Studying the Effect of Stray Capacitance on the Measurement Accuracy of the CVT Based on the Boundary Element MethodChuan Xiang0Xinwei Chen1Hongge Zhao2Zejun Ren3Guoqing Zhao4College of Marine Electrical Engineering, Dalian Maritime University, Dalian 116026, ChinaState Grid Shandong Electric Power Company, Jinan 250001, ChinaCollege of Marine Electrical Engineering, Dalian Maritime University, Dalian 116026, ChinaCollege of Marine Electrical Engineering, Dalian Maritime University, Dalian 116026, ChinaDalian North Instrument Transformer Group Co., Ltd., Dalian 116200, ChinaThe capacitive voltage transformer (CVT) is a special measuring and protecting device, which is commonly applied in high-voltage power systems. Its measurement accuracy is affected seriously by the stray capacitances of the capacitance voltage divider (CVD) to ground and other charged parts. In this study, based on the boundary element method, a mathematical model was established firstly to calculate the stray capacitance. Then, the voltage distribution of the CVD was obtained by the CVD’s equivalent circuit model. Next, the effect of stray capacitance on the voltage distribution and the voltage difference ratio (VDR) of CVD was analysed in detail. We finally designed three types of shield and optimized their structure parameters to reduce VDR. The results indicated that the average deviation rate between calculated and experimental measured voltages is only 0.015%; that is to say, the method has high calculation precision. The stray capacitance of the CVD to ground is far larger than that of the CVD to the high-voltage terminal. It results in the inhomogeneous distribution of voltage and the increase of VDR. For the test CVT, its VDR exceeds the requirement of class 0.2. Among all of the three types of shield, the C type reduced the VDR of the test CVT the most. After optimizing the structure parameters of C-type shield, the VDR is further reduced to 0.08%. It is not only in accord with the requirement of class 0.2 but also has an adequate margin.http://dx.doi.org/10.1155/2021/1155443
spellingShingle Chuan Xiang
Xinwei Chen
Hongge Zhao
Zejun Ren
Guoqing Zhao
Studying the Effect of Stray Capacitance on the Measurement Accuracy of the CVT Based on the Boundary Element Method
Complexity
title Studying the Effect of Stray Capacitance on the Measurement Accuracy of the CVT Based on the Boundary Element Method
title_full Studying the Effect of Stray Capacitance on the Measurement Accuracy of the CVT Based on the Boundary Element Method
title_fullStr Studying the Effect of Stray Capacitance on the Measurement Accuracy of the CVT Based on the Boundary Element Method
title_full_unstemmed Studying the Effect of Stray Capacitance on the Measurement Accuracy of the CVT Based on the Boundary Element Method
title_short Studying the Effect of Stray Capacitance on the Measurement Accuracy of the CVT Based on the Boundary Element Method
title_sort studying the effect of stray capacitance on the measurement accuracy of the cvt based on the boundary element method
url http://dx.doi.org/10.1155/2021/1155443
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AT honggezhao studyingtheeffectofstraycapacitanceonthemeasurementaccuracyofthecvtbasedontheboundaryelementmethod
AT zejunren studyingtheeffectofstraycapacitanceonthemeasurementaccuracyofthecvtbasedontheboundaryelementmethod
AT guoqingzhao studyingtheeffectofstraycapacitanceonthemeasurementaccuracyofthecvtbasedontheboundaryelementmethod