Approximation and Prediction of AC Magnetization Curves for Power Transformer Core Analysis

Tang, Qi; Wang, Zhongdong; Anderson, Philip Ian; Jarman, Paul; Moses, Anthony John

doi:10.1109/tmag.2014.2372672

Cited by 18 publications

(4 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The above result shows that the DNN is better than the other traditional models in both the RMSE and correlation coefficient. In addition, compared to previous research in [22], where the best model achieved a 99.92% correlation coefficient, the proposed DNN model in this paper also achieves the best performance. Finally, the magnetization curve from DNN is given in Figure 6 and the saturation magnetic flux density is around 1.7 T. The SVR is used for calculating H c and H amp under different excitation voltages.…”

Section: Magnetization Modelingmentioning

confidence: 56%

Modeling the Hysteresis Characteristics of Transformer Core under Various Excitation Level via On-Line Measurements

Pan

Guzzomi

2018

Electronics

View full text Add to dashboard Cite

In this paper, the hysteresis characteristics of a transformer core are determined from limited on-line measured voltages and currents under certain excitations. A method for calculating the magnetization curve and hysteresis loops of the transformer core under various excitation is developed based on limited excitation conditions, and using the deep neural network, support vector regressor and the Wlodarski model. The coercivity and the amplitude of magnetic field strength of hysteresis loops can be captured with high accuracy based on this method. Then, a finite element model of the transformer core is constructed to predict the distributed magnetic flux density and the excitation current using the calculated hysteresis loops. The currents from various excitation voltages on two different transformer structures are also measured to compared with simulated currents. The outcome indicates that the overall hysteresis loops and magnetization curve of the transformer core may be useful for modeling the magnetic field and excitation current under any voltage excitation.

show abstract

Section: Magnetization Modelingmentioning

confidence: 56%

Modeling the Hysteresis Characteristics of Transformer Core under Various Excitation Level via On-Line Measurements

Pan

Guzzomi

2018

Electronics

View full text Add to dashboard Cite

show abstract

“…The calculations were made for the steady state for different connections of windings on both sides of the transformer. A linear magnetic model (with constant inductances) was adopted because the non-linearity of magnetization does not affect the currents, voltages, and power distribution in the transformer supplied with the rated voltage [21,22]. Due to the rated voltage supplying the transformer, the power losses in the core were omitted as relatively small in a loaded transformer and also constant in all the examined situations.…”

Section: Methodsmentioning

confidence: 99%

Control of the Transformer Phase Powers Using a Single-Phase Voltage Source

Drabek

Dybowski

2021

Energies

View full text Add to dashboard Cite

Power flow in three-phase distribution grids containing single-phase prosumer voltage sources strongly depends on the RMS value of the voltage of these sources and their phase shifts in relation to the grid voltage. The ideal way to control single-phase prosumer sources should guarantee no return active power to the MV grid through a distribution transformer and no additional reactive power flows in the LV grid. This means that the active power of the one-phase voltage source is consumed by other single-phase customers (in the same phase or in other phases) and the reactive power of this source is equal to zero. The paper presents the results of the investigations of the dynamic control system of a single-phase voltage source that allows meeting these conditions. On the basis of steady-state calculations, the static characteristics of the above-mentioned control, needed to determine of the proper working point of a prosumer source were also obtained. The control process involves the control of the RMS value and phase angle of the voltage source against the phase voltage of the LV grid, to which the source is connected, with simultaneous control of the current phase angle issued by the power source against voltage. The result of the research is the confirmation of the necessity of using a zig–zag connection of the secondary side of distribution transformers. The developed control system of the prosumer voltage source does not fully control the active power of individual phases of the distribution transformer. The paper shows that the power losses in a distribution transformer strongly depend not only on the active power of the prosumer source, but also on its effective voltage and phase in relation to the transformer voltage.

show abstract

“…By fitting a single model. These methods fit the entire B(H) data to a simple function, such as a hyperbola [52], arctan, tanh [53][54][55][56][57], coth [8], exponential [56], polynomial [58], or splines [59]. Over the past century, scores of attempts have been made to model the B(H) curves accurately [60].…”

Section: Other Prior Methods To Locate Kmentioning

confidence: 99%

“…Over the past century, scores of attempts have been made to model the B(H) curves accurately [60]. However, most B(H) models are known to suffer from significant errors [59,61,62]. In addition, Peng [10] found that the k predicted by the tanh model differs significantly from that of tests.…”

Section: Other Prior Methods To Locate Kmentioning

confidence: 99%

Selection of Optimal Magnets for Traction Motors to Prevent Demagnetization

Rao¹,

Bagianathan

2021

Machines

View full text Add to dashboard Cite

Currently, permanent-magnet-type traction motors drive most electric vehicles. However, the potential demagnetization of magnets in these motors limits the performance of an electric vehicle. It is well known that during severe duty, the magnets are demagnetized if they operate beyond a ‘knee point’ in the B(H) curve. We show herein that the classic knee point definition can degrade a magnet by up to 4 grades. To prevent consequent excessive loss in performance, this paper defines the knee point k as the point of intersection of the B(H) curve and a parallel line that limits the reduction in its residual flux density to 1%. We show that operating above such a knee point will not be demagnetizing the magnets. It will also prevent a magnet from degenerating to a lower grade. The flux density at such a knee point, termed demag flux density, characterizes the onset of demagnetization. It rightly reflects the value of a magnet, so can be used as a basis to price the magnets. Including such knee points in the purchase specifications also helps avoid the penalty of getting the performance of a low-grade magnet out of a high-grade magnet. It also facilitates an accurate demagnetization analysis of traction motors in the worst-case conditions.

show abstract

Approximation and Prediction of AC Magnetization Curves for Power Transformer Core Analysis

Cited by 18 publications

References 29 publications

Modeling the Hysteresis Characteristics of Transformer Core under Various Excitation Level via On-Line Measurements

Modeling the Hysteresis Characteristics of Transformer Core under Various Excitation Level via On-Line Measurements

Control of the Transformer Phase Powers Using a Single-Phase Voltage Source

Selection of Optimal Magnets for Traction Motors to Prevent Demagnetization

Contact Info

Product

Resources

About