Comparison of the Wideband Power Sources Used to Supply Step-Up Current Transformers for Generation of Distorted Currents

Kaczmarek, M.; Kaczmarek, Piotr

doi:10.3390/en13071849

Cited by 21 publications

(17 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The measuring system was supplied from the PWM based programmable AC power source [ 26 ] The step-up transformer was used to increase its output voltage to 2 kV or 1.5 kV RMS. These values are equal to 10% of the rated RMS value of the primary voltage of the tested inductive VT.…”

Section: The Measuring System Used For Evaluation Of the Transformation Accuracy Of Slow-front Transient Overvoltagesmentioning

confidence: 99%

“…The objects of the research are dual pole VTs, two with rated primary voltage equal to 20 kV and one with rated primary voltage equal to 15 kV. Their properties are studied under switching overvoltages caused by failure in operation of the Pulse-Width Modulation (PWM) based programmable AC source when used to supply a step-up transformer [ 26 ].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Transformation of Transient Overvoltages by Inductive Voltage Transformers

Kaczmarek

Brodecki

2021

Sensors

Self Cite

View full text Add to dashboard Cite

Overvoltage transients occur after any type of switching activity in a power network, such as breaker operation, fault occurrence/clearance and rapid load change. This distortion of voltage is transformed to the secondary circuit of a voltage transformer. The maximum values of such impulses may many times exceed the rated value of its secondary voltage. This can lead to malfunction of measuring or protection devices connected to the secondary circuit of a voltage transformer and even their damage. The paper presents the application of determined values of ratio error at harmonics of the inductive voltage of the transformer to predict the value of transformed slow-front transient overvoltage to their secondary circuits. This will help to prevent malfunction of measuring or protection devices connected to the secondary side of the voltage transformer and increase their safety of operation. The inductive voltage transformer equivalent circuit for transformation of higher frequency components of distorted voltage must be extended with internal capacitances of windings. This is caused by the fact that the resonance phenomenon of the slow-front transient overvoltage results from leakage inductance and capacitance of primary winding, not from the magnetic core. Therefore, this behaviour is independent from the value of the applied voltage.

show abstract

Section: The Measuring System Used For Evaluation Of the Transformation Accuracy Of Slow-front Transient Overvoltagesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Transformation of Transient Overvoltages by Inductive Voltage Transformers

Kaczmarek

Brodecki

2021

Sensors

Self Cite

View full text Add to dashboard Cite

show abstract

“…The measuring circuit is supplied by the programmable power voltage source through the insulating transformer [33]. If required for testes rms value of the primary current exceeds 20 A application of the inductive high current testing transformer for supplying of the measuring circuit with distorted current is required [34].…”

Section: Figure 1 the Measuring Circuit To Determine The Values Of Cmentioning

confidence: 99%

Nonlinearity of Magnetic Core in Evaluation of Current and Phase Errors of Transformation of Higher Harmonics of Distorted Current by Inductive Current Transformers

Kaczmarek

Stano

2020

IEEE Access

Self Cite

View full text Add to dashboard Cite

The novelty of the paper contributes to the increase of the reliability of the methods used for evaluation of the inductive CTs accuracy of transformation of the distorted current. The results of performed analyses shows that the values of current and phase errors of transformation of the low order higher harmonics by inductive CT depends significantly from the phase angle between transformed higher harmonics of the distorted primary current and the self-generated higher harmonics of the secondary current. Moreover, higher harmonics of the distorted primary current may increase the peak value of the magnetic flux density in the magnetic core. Then the impact of the self-generated low order harmonics resulting from the nonlinearity of the magnetic core on values of current and phase errors of transformation of the higher harmonics of the distorted primary current is increased. Proposed evaluation procedure enables determination of the maximum values of current and phase errors of transformation of the higher harmonics of the distorted primary current. It is essential to determine the accuracy class. In such approach the impact of the secondary current's distortion caused by the nonlinearity of the magnetic core and the influence of the harmonic distortion on the peak value of the magnetic flux density are considered. Therefore, transformation accuracy of tested CT is ensured for specified range and type of the load of the secondary winding, rms values of primary current and its distortion. INDEX TERMS inductive current transformer, nonlinearity of magnetic core, transformation accuracy, distorted current, power quality, composite error, current and phase errors at harmonics.

show abstract

“…The phase shift of a given harmonic in the output voltage of DA in relation to the same frequency harmonic in the input voltage of TVT: TVTDA. A wideband voltage divider was used as the source of the reference voltage [27]. The calibration method for this divider is presented in [28,29].…”

mentioning

confidence: 99%

“…A wideband voltage divider was used as the source of the reference voltage [27]. The calibration method for this divider is presented in [28,29].…”

mentioning

confidence: 99%

3D Electromagnetic Field Analysis Applied to Evaluate the Accuracy of a Voltage Transformer under Distorted Voltage

2020

Self Cite

View full text Add to dashboard Cite

Voltage transformers (VTs) are an important element of the measuring system that allows measuring the energy flow in medium and high voltage networks. Additional problems with the accuracy of the measurement introduced by the appearance of sources and nonlinear receivers cause deformation of the voltage shape in the energy system. Due to the high metrological requirements, the design of voltage transformers requires high accuracy (for class 0.2 ΔU ≤ 0.2, phase displacement ≤10 min), which is not possible with the use of analytical methods using approximate models. Therefore, only the application of numerical modeling by the finite element method, taking into account real three-dimensional phenomena, allows achieving high modeling accuracy. The article concerns the phenomenon of the influence of voltage higher harmonics of supply voltage on the accuracy (up to the 100th harmonic) of the measuring inductive voltage transformer (IVT). The applied modeling method takes into account the phenomena in the transformer core and the circuit equations resulting from the winding arrangement, which allows for the study of the deformation voltage transformation. Experimental tests on a real model to evaluate the method used were necessary. The article presents simulations for a model transformer, and results have been confirmed by experimental tests.

show abstract

Comparison of the Wideband Power Sources Used to Supply Step-Up Current Transformers for Generation of Distorted Currents

Cited by 21 publications

References 14 publications

Transformation of Transient Overvoltages by Inductive Voltage Transformers

Transformation of Transient Overvoltages by Inductive Voltage Transformers

Nonlinearity of Magnetic Core in Evaluation of Current and Phase Errors of Transformation of Higher Harmonics of Distorted Current by Inductive Current Transformers

3D Electromagnetic Field Analysis Applied to Evaluate the Accuracy of a Voltage Transformer under Distorted Voltage

Contact Info

Product

Resources

About