Reduction of inrush current in single-phase transformer using virtual air gap technique

Molcrette, V.; Kotny, Jean-Luc; Swan, Jean-Paul; Brudny, J.F.

doi:10.1109/20.706479

Cited by 73 publications

(25 citation statements)

References 2 publications

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“…The physical effects seen in a virtual air gap device are similar to those seen in a device with a real air gap [4]. This behaviour is accomplished by saturating a local region using embedded DC windings within the core.…”

Section: Virtual Air Gapmentioning

confidence: 77%

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Harmonics and Dynamic Response of a Virtual Air Gap Variable Reactor

Dolan

Lehn

Taufik

2012

2012 Ninth International Conference on Information Technology - New Generations

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As more sustainable energy generation is integrated into power grid, the control of power flow in an efficient and effective manner becomes more and more essential. A new innovative device is presented that allows the control of line power flow without the high harmonics and efficiency losses of traditional methods. This paper presents the dynamic response and the harmonics of a laboratory prototype Virtual Air Gap Variable Reactor (VAG-VR) and compares them with those of a thyristor controlled reactor (TCR). Variable Reactors have many applications in the power industry. Their use allows control of line power flow, voltage regulation, as well as damping of power oscillations and subsynchronous resonances. A variable reactor is most commonly implemented as a TCR by switching in and out a constant reactance to achieve an averaged variable reactance. By using a virtual air gap, implementation of a continuously variable reactance is possible with a better dynamic response and without introducing the harmonics created by the thyristor switching of a TCR.

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Section: Virtual Air Gapmentioning

confidence: 77%

“…The concept of a virtual air gap (VAG) was first introduced and applied to inrush current limiting in transformers [4]. Through saturation of small localized regions of the transformer core, a region of low permeability may be produced that spans the core's cross section similar to an air gap.…”

Section: Introductionmentioning

confidence: 99%

Harmonics and Dynamic Response of a Virtual Air Gap Variable Reactor

Dolan

Lehn

Taufik

2012

2012 Ninth International Conference on Information Technology - New Generations

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“…Molcrette et al (1998) and an IEEE working group, Tziouvaras et al (2000) both reported that using a small quantity of the magnetic flux in the air gap of an iron core prevents magnetic saturation. Vakilian and Degeneff (1994) argued that utilizing nonmagnetic materials and a linear coupler to substitute for the iron core of a CT would eliminate magnetic saturation.…”

Section: Introductionmentioning

confidence: 98%

Design of a new Hall overcurrent protection relay with instantaneous characteristics

Tsai

Chen

et al. 2015

Journal of the Chinese Institute of Engineers

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Traditional current transformers (CTs) detect fault currents and transfer signals to overcurrent protection relays for indicative and protective purposes as a part of the protection coordination system in a power network. By characterizing the transient response to a power failure, a reliable and accurate protection relay can be achieved. In this study, we propose a new Hall overcurrent protection relay (HCO) using Hall effect CTs based on the transient exponential signatures of fault current analysis. To minimize the distortion phenomena seen in fault current measurements because of the hysteresis caused by the CTs' iron cores, and to obtain faster tripping signals, we adapt an HCO to accurately detect nonsinusoidal fault waves and to improve protection coordination accuracy. The experimental results indicate that the HCO significantly improves the protection system's accuracy and response speed for various power systems applications.

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“…The technology called "virtual gap or virtual air gap" was proposed in [1]. The principal idea of a virtual gap is to make holes on an iron core and to wind a winding through them.…”

Section: Introductionmentioning

confidence: 99%

“…In [1] virtual gaps have been used to limit the inrush current that a transformer draws from the line. In [2] the virtual gap technology has been used to produce an enhanced soldering machine.…”

Section: Introductionmentioning

confidence: 99%

Control of the Magnetizing Characteristics of a Toroidal Core Using Virtual Gap

Magdaleno¹,

Rojas

2010

2010 IEEE Electronics, Robotics and Automotive Mechanics Conference

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A study of the technology of the virtual gap in a toroidal core is analyzed and showed in this paper. We made a study about of the effects of a virtual gap in a toroidal core. Through nonlinear finite element simulations we studied the effects that a virtual gap has on a toroidal core. We realized several analysis magnetic static (using only DC currents). The finite element simulations show the function of a virtual gap in a toroidal core and how this technology can help to control the magnetizing characteristics of a toroidal core. Furthermore, we proposed a method to estimate the equivalent air gap using the results obtained with a virtual gap in the same toroidal core. Moreover, we show how a virtual gap can control the characteristics of the magnetizing curve of a toroidal core varying the DC current intensity in the windings of the holes and how we can vary the saturation degree and the size of the virtual gap of the same manner.

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Reduction of inrush current in single-phase transformer using virtual air gap technique

Cited by 73 publications

References 2 publications

Harmonics and Dynamic Response of a Virtual Air Gap Variable Reactor

Harmonics and Dynamic Response of a Virtual Air Gap Variable Reactor

Design of a new Hall overcurrent protection relay with instantaneous characteristics

Control of the Magnetizing Characteristics of a Toroidal Core Using Virtual Gap

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