Measurement of λ-i characteristics of asymmetric three-phase transformers and their applications

Fuchs, E.F.; You, Y.

doi:10.1109/ichqp.2000.897004

Cited by 14 publications

(19 citation statements)

References 4 publications

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“…The magnetizing windings were energized by laboratory power supply PS 8000 DT type (Elektro-Automatik GmbH) controlled by function generator AFG3011 type (Tektronix Inc.). The hysteresis Φ c (Θ) characteristics of the tested transformer are calculated from the set of measured voltages and currents (Dolinar et al, 2006; Magnetic hysteresis Fuchs and You, 2000). The flux density is obtained by numerical integration of the voltage induced in the measurement coil.…”

Section: Parameter Identification Of the Feedback Preisach Modelmentioning

confidence: 99%

Representation of magnetic hysteresis in a circuit model of a single-phase transformer

Wilk

2015

COMPEL

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Purpose -The paper presents a mathematical model for the hysteresis phenomenon in a multi-winding single-phase core type transformer. The set of loop differential equations was developed for Kth winding transformer model where the flux linkages of each winding includes a flux common Φ to all windings as function of magneto motive force Θ of all windings. The purpose of this paper is to first determine a hysteresis nonlinearity involved in Φ(Θ) function using modified Preisach theory and second to develop new analytical formula of Preisach distribution function (PDF). Design/methodology/approach -It is assumed in this paper that flux linkage characteristics Ψ(i) of each winding have nonlinear component due to the magnetization characteristic of the steel core and sum of linear components due to the self and mutual leakage fluxes. This nonlinear component of Ψ(i) characteristic can be expressed as a flux common Φ to all windings vs ampere-turns Θ of all windings. The nonlinear flux linkage characteristics Ψ(i) of the tested transformer are calculated from the set of measured terminal voltages and terminal currents. To simulate magnetic behavior of the iron core the feedback scalar Preisach model of hysteresis is proposed which gives more accurate predictions than classical model. For this hysteresis model the PDF and feedback function are needed. The intend of this paper is to find these function as an analytical formulas which are convenient for numerical simulations. For identification of the PDF and feedback function parameters of the considered iron core of tested transformer the Levenberg-Marquardt optimization algorithm was used. Findings -The flux common to all windings is calculated by integrating the induced voltages of the appropriate windings. In this paper the PDF is proposed as a functional series including two dimensional Gauss expressions. In order to proper approximation of hysteresis nonlinearity of the tested iron core the first three terms of functional series of the PDF have been used. In the optimization algorithm only initial and descending limiting hysteresis curves Φ(Θ) were utilized. The feedback function for proposed hysteresis model is assumed as third-order polynomial. The hysteresis model has been successfully validated by comparing the calculated and measured results of Φ(Θ) hysteresis curves. This hysteresis model can be used in transient and steady state simulations of tested transformer taking into account the hysteresis phenomenon. The developed hysteresis model can be also used for analysis of the influence of remnant flux on the operation of tested transformer especially in transient states. Originality/value -In this paper the feedback Preisach hysteresis model is involved in the flux common to all windings vs ampere-turns of all windings. The new PDF is proposed as functional series including two dimensional Gauss expressions. For tested transformer the three first terms of this functional series may be used for proper approximation of hysteresis nonlinearities.

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Section: Parameter Identification Of the Feedback Preisach Modelmentioning

confidence: 99%

Representation of magnetic hysteresis in a circuit model of a single-phase transformer

Wilk

2015

COMPEL

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“…• R 1 equivalent resistance representing the classical and anomalous eddy current losses; The linkage fluxes 0 (i 0 , i 1 ) 1 (i 0 , i 1 ) characteristics of the tested transformer are calculated from the set of measured voltages and currents [15], [16]. The flux density is obtained by numerical integration of the voltage induced in the measurement coil.…”

Section: Transformer System Modelmentioning

confidence: 99%

“…The Preisach distribution function ( , ) has been accepted in accordance with the static model of hysteresis given in [16]. This function is formulated using a finite series: …”

Section: Transformer System Modelmentioning

confidence: 99%

Simulation of the remanence influence on the transient states of the single-phase transformer including feedback Preisach model

Wilk

Michna

Cichowski

2014

IECON 2014 - 40th Annual Conference of the IEEE Industrial Electronics Society

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This paper presents the results of the experimental and simulation investigation concerning the influence of remanence in the core of a single-phase transformer at the noload transient state. Experimental studies consisted of the discharge of the capacitor through the primary winding at several different values of the residual magnetic flux. The paper presents a model of the transformer test system, taking into account the magnetic hysteresis phenomenon based on the Preisach model with feedback. The model was used to simulate the transient and steady state of the test system, taking into account the value and the sign of the remanence in the toroidal tape wound core. It was concluded that the induction of remanence has a significant impact on the value of the inrush current. This model can be used for simulation of the transformer systems transient state, taking into account the magnetic hysteresis and the remanence.

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“…Note that a three-limb, three-phase transformer has a smaller zero-sequence reactance than that of a bank of three single-phase transformers or that of a five-limb, three-phase transformer [38][39][40][41].…”

Section: Transformer Connections and Single-phase (Pole) Switching Atmentioning

confidence: 99%

“…The per-phase GIC can be many times larger in magnitude than the rms AC magnetizing current of a transformer. The net result is a DC bias in the transformer core flux, resulting in a high level of half-cycle saturation [40,54]. This half-cycle saturation of transformers operating within a power system is the source of nearly all operating and equipment problems caused by GICs during magnetic storms (reactive power demand and its associated voltage drop).…”

Section: Power System Effects Of Gicmentioning

confidence: 99%

Harmonic Models of Transformers

2008

Power Quality in Power Systems and Electrical Machines

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Extensive application of power electronics and other nonlinear components and loads creates single-time (e.g., spikes) and periodic (e.g., harmonics) events that could lead to serious problems within power system networks and its components (e.g., transformers). Some possible impacts of poor power quality on power transformers are 9 saturating transformer core by changing its operating point on the nonlinear ~-i curve, 9 increasing core (hysteresis and eddy current) losses and possible transformer failure due to unexpected high losses associated with hot spots, 9 increasing (fundamental and harmonic) copper losses, 9 creating half-cycle saturation in the event of even harmonics and DC current, 9 malfunctioning of transformer protective relays, 9 aging and reduction of lifetime, 9 reduction of efficiency, 9 derating of transformers, 9 decrease of the power factor, 9 generation of parallel (harmonic) resonances and ferroresonance conditions, and 9 deterioration of transformers' insulation near the terminals due to high voltage stress caused by lightning and pulse-width-modulated (PWM) converters.Pfe = Phys + Peddy = ghys (Bmax)Sf + geddy(Bmax)2f 2, (2-1) where Phys, Peddy, Bmax, and f are hysteresis losses, eddy-current losses, maximum value of flux density, and fundamental frequency, respectively. Khys is a constant for the grade of iron employed and Keddy is the eddy-current constant for the conductive material. S is the Steinmetz exponent ranging from 1.5 to 2.5 depending on the operating point of transformer core.9 Elsevier Inc. All rights reserved. I ~,H I i r 9 FIGURE 2.4 Magnetic field strength inside and outside of a conductor. / / I i \ % o 9 "% ~Ho3 / %% u / / %

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Measurement of λ-i characteristics of asymmetric three-phase transformers and their applications

Cited by 14 publications

References 4 publications

Representation of magnetic hysteresis in a circuit model of a single-phase transformer

Representation of magnetic hysteresis in a circuit model of a single-phase transformer

Simulation of the remanence influence on the transient states of the single-phase transformer including feedback Preisach model

Harmonic Models of Transformers

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