Reference voltage divider designed to operate with oscilloscope to enable determination of ratio error and phase displacement frequency characteristics of MV voltage transformers

Kaczmarek, M.; Szatilo, T.

doi:10.1016/j.measurement.2015.02.045

Cited by 18 publications

(12 citation statements)

References 17 publications

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“…The maximum rms value of the secondary distorted current is limited by the maximum permissible rms value of the primary voltage. The course of the curves for each configuration of the sections of the secondary winding results from the value of the voltage drop on the impedance of the windings calculated from (15). Furthermore, considering the restriction from Tables 4 and 3, there is a limitation of the maximum rms value of the output current for each configuration of sections of the secondary winding.…”

Section: Required Properties Of the High Current Testing Transformer mentioning

confidence: 99%

Application of the inductive high current testing transformer for supplying of the measuring circuit with distorted current

Kaczmarek

Stano

2019

IET Electric Power Applications

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The increasing number of non-linear loads and renewable energy sources causes a decrease in the power quality in the power networks. Therefore, tests of current transformers should be performed in similar conditions. This requires generation by a high current testing transformer of distorted currents that rms values are from a few hundred to several thousands of amperes with a given harmonics levels. However, its frequency band of operation is limited by inductances of its windings and connected load that result from the length and parameters of the used current track and connected device under test. To ensure the constant rms value of higher harmonic of distorted secondary current with the increase of its frequency proportional increase of the rms value of this harmonic in distorted primary voltage of the high current testing transformer is required. However, the maximum permissible value of primary voltage is limited by the dielectric strength of insulation of the primary winding. The purpose of presented studies is to determine the factors that condition the frequency band of operation of a high current testing transformer and limits the range of higher harmonics while testing of the transformation accuracy of instrument current transformers for distorted currents.

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Section: Required Properties Of the High Current Testing Transformer mentioning

confidence: 99%

Application of the inductive high current testing transformer for supplying of the measuring circuit with distorted current

Kaczmarek

Stano

2019

IET Electric Power Applications

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“…Verification steps of instrument transformers and protocols consisting of the most important parameters of the tested power quality instruments were proposed in [4]. Determination of the voltage and phase errors of inductive voltage transformers (VTs) requires usage of a wideband reference voltage divider [5][6][7]. The measuring system may consist of a power network analyzer or digital power meter enabling computation of the FFT spectrum of the measured distorted voltage [8,9].…”

Section: Introductionmentioning

confidence: 99%

Wideband Self-Calibration Method of Inductive CTs and Verification of Determined Values of Current and Phase Errors at Harmonics for Transformation of Distorted Current

Stano

Kaczmarek

2020

Sensors

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Self-calibration of a designed wideband inductive current transformer (CT) was carried out in the ampere-turns condition. This method does not require a reference transducer. The values of current and phase errors at the harmonics of frequencies from 100 Hz to 5 kHz were determined for the distorted primary current of the rated main frequency equal to 50 Hz. These results were verified based on the comparison of values measured between two CTs and calculated as the difference between values obtained from their calibration. Moreover, from vectorial diagrams drawn for transformation of the higher harmonics, the source of the change in the values of current and phase errors with frequency is explained. Furthermore, the method for calculation of the values of the corresponding harmonics of the current associated with the active power losses in the core and the magnetization current is presented.

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“…Capacitive dividers and electromagnetic voltage transformers are usually used for AC voltage measurement. Resistance voltage dividers can be used for either DC or AC voltage measurement [5]. However, the self-heating effect of resistances causes additional power consumption and inaccuracy problems.…”

Section: Introductionmentioning

confidence: 99%

A Differential Resonant Voltage Sensor Consisting of Piezo Bimorph and Quartz Crystal Double-Ended Tuning Fork Resonators

Huang

Bian

2019

Sensors

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A differential resonant voltage sensor with frequency output was developed by bonding two quartz crystal double-ended tuning forks (DETFs) on both sides of a piezo bimorph. The applied voltage induced tensile and compression deformation in the upper and bottom layers of the piezo bimorph, which caused the resonant frequency of the dual DETFs to increase and decrease, respectively. In this case, the differential output of the resonance frequencies of the dual DETFs greatly reduced the effect of temperature drift. In addition, the input resistance of the piezo bimorph reached a few hundred GΩ, which caused almost no influence on the DC voltage under test. The fabricated device showed a linear characteristic over its measurement range of ±700 V with a sensitivity of 0.75 Hz/V, a resolution of 0.007% (0.1 V) and hysteresis of 0.76% of the full range. The quality factor of the DETFs was about 3661 (in air). This novel resonant voltage sensor with its extremely low power consumption is promising for measuring or monitoring DC voltage in various fields.

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Reference voltage divider designed to operate with oscilloscope to enable determination of ratio error and phase displacement frequency characteristics of MV voltage transformers

Cited by 18 publications

References 17 publications

Application of the inductive high current testing transformer for supplying of the measuring circuit with distorted current

Application of the inductive high current testing transformer for supplying of the measuring circuit with distorted current

Wideband Self-Calibration Method of Inductive CTs and Verification of Determined Values of Current and Phase Errors at Harmonics for Transformation of Distorted Current

A Differential Resonant Voltage Sensor Consisting of Piezo Bimorph and Quartz Crystal Double-Ended Tuning Fork Resonators

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