New High-Frequency Core Loss Measurement Method With Partial Cancellation Concept

Hou, Dibo; Mu, Mingkai; Lee, Fred C.; Li, Qiang

doi:10.1109/tpel.2016.2573273

Cited by 85 publications

(60 citation statements)

References 19 publications

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“…Among others, in case of powder cores, huge measurement errors are often encountered, which occurs as a result of the phase shift between voltage and current, due to the low relative permeability (11) (12) . Removing the phase-shift error in the core is important while obtaining the core losses in a magnetic material with low relative permeability, and it has been proposed before in (13) (14) . However, this method is difficult to implement, since it requires fine tuning of the cancellation element which can be very time consuming.…”

Section: Electrical Methodsmentioning

confidence: 99%

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Comparative Evaluation of Electrical and Calorimetric Methods to Estimate Core Loss in Powder Cores

et al. 2019

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The utilization of powder cores for many power electronic applications has drawn a significant amount of attention owing to their attractive magnetic properties. However, because of their low relative permeability characteristics, a precise measurement of the core loss is very difficult to obtain. Imprecise estimation of the core loss may lead to an inaccurate thermal design of power converters. Measuring and calculating the accurate value of the core loss allows the circuit designer to design a more efficient system. This paper discusses the revalidation of electrical measurement by comparing the electrical method with the calorimetric method in powder cores. The calorimetric method is one of the most promising methods to accurately measure the core loss; however, it is time consuming. A difference less than 10% has been reported for the core loss measurement error while comparing the electrical method and the calorimetric method in various conditions. These results indicate that the electrical method using the B-H analyzer is effective for measuring the core losses in some conditions for powder cores. Along with the theoretical discussion, simulation and experimental tests are also conducted.

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Section: Electrical Methodsmentioning

confidence: 99%

“…In general, core loss measurement methods are categorized into two techniques: (1) electrical method (7)- (14) , (2) calorimetric method (15)- (19) . a) Correspondence to: Yuki Ishikura.…”

Section: Introductionmentioning

confidence: 99%

Comparative Evaluation of Electrical and Calorimetric Methods to Estimate Core Loss in Powder Cores

et al. 2019

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“…In this paper, all the methods relying on electrical measurements and two windings are considered as the 'twowinding method' [4], [5], [6], [7]. One winding (excitation winding) is used to excite a core with a known current, while the other winding (sensing winding) is kept open and its terminal voltage is measured (Fig.…”

Section: Introductionmentioning

confidence: 99%

Experimental Extraction of Winding Resistance in Litz-Wire Transformers—Influence of Winding Mutual Resistance

Niyomsatian

Gyselinck

Sabariego

2019

IEEE Trans. Power Electron.

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The extraction of winding resistance from impedance measurements needs a compensation of undesirable effects e.g. core loss and distributed winding capacitance. This paper rigorously shows that the core loss (or core-loss resistance) measured with the two-winding method always includes the effect of the winding mutual resistance. At high frequencies, this effect becomes more prominent and can cause an overestimation of the measured core-loss resistance. As a result, the compensated winding resistances can be significantly underestimated.To mitigate this effect, this paper proposes to measure the core-loss resistance on an auxiliary 1:1 transformer with single-turn windings. Consequently, it is scaled to obtain the actual core loss. The proposed analysis and method is applicable to multi-winding systems. For validation, this paper considers a gapped transformer with litz-wire winding for highfrequency operations. The experimental results are validated against the results from its 3D finite element (FE) model. The litz-wire winding is considered in the FE model by means of a homogenization approach. With the method proposed in this paper, the experimentally extracted winding resistances become more accurate and are in good agreement with the FE results.

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“…Equation (1) indicates that, the closer to 90 • is Φ v−i , the more sensitive is the percentage error to ∆Φ. Different modifications on the measurement circuit structure has been proposed by the work of [17], [18] and [19], so as to drag Φ v−i away from 90 • and thus decrease the sensitivity to ∆Φ. There high excitation frequency of several or tens of MHz was discussed, the frequency in this work (50 kHz) however, is far below that range.…”

Section: Discussion Of Measurement Accuracymentioning

confidence: 99%

Modeling Frequency-Dependent Core Loss of Ferrite Materials Using Permeance–Capacitance Analogy for System-Level Circuit Simulations

Luo

Dujić

Allmeling³

2019

IEEE Trans. Power Electron.

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Ferrite core materials are preferred for magnetic components in power electronic converters considering their low cost and high permeability. Thanks to the negligible electrical conductivity, core loss is dominated by the frequency independent hysteresis effect in most operating conditions. In the applications of high switching frequency under certain modulation scheme, however, the core loss of ferrite materials do exhibit obvious frequency dependency, known as relaxation effect, which is strongly influenced by the magnetic flux's rate of change and can not be ascribed to material conductivity. In order to incorporate the core loss including both frequency dependent-and independent effect into system level simulation environment of power converters, so that the system efficiency can be pre-evaluated during the design-phase as reference for optimization, dynamic model which is physically intuitive and easy to parametrise is desired. This work proposes an approach to model the core loss of ferrite materials combining both frequency dependent relaxation effect and frequency independent hysteresis, which can be flexibly applied for various operation conditions with good accuracy.

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New High-Frequency Core Loss Measurement Method With Partial Cancellation Concept

Cited by 85 publications

References 19 publications

Comparative Evaluation of Electrical and Calorimetric Methods to Estimate Core Loss in Powder Cores

Comparative Evaluation of Electrical and Calorimetric Methods to Estimate Core Loss in Powder Cores

Experimental Extraction of Winding Resistance in Litz-Wire Transformers—Influence of Winding Mutual Resistance

Modeling Frequency-Dependent Core Loss of Ferrite Materials Using Permeance–Capacitance Analogy for System-Level Circuit Simulations

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