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Proceedings ArticleDOI

Design and implementation of a sinusoidal flux controller for core loss measurements

TL;DR: In this article, a sinusoidal flux controller has been proposed for a core loss tester for eliminating the higher order harmonics from the flux passing through the core, which can achieve zero steady state error and fast tracking as well as being robust to periodic errors.
Abstract: In this paper, design and implementation of a sinusoidal flux controller has been proposed for a core loss tester for eliminating the higher order harmonics from the flux passing through the core. The core loss test is performed with a toroidal transformer that consists of a main and sense windings wound on a toroidal core. The flux through the core is calculated with the numerical integration of the sense coil voltage. The controller commands the voltage applied to the main winding to keep the sense coil voltage thus the flux waveform sinusoidal. A single-phase SiC inverter operating at 150 kHz has been developed to generate the waveforms, an LC filter is used between the converter and the toroidal transformer to smooth the pulsating inverter output voltages. To be able to achieve zero steady state error and fast tracking as well as being robust to the periodic errors, a new controller is proposed. The proposed controller includes the periodic, conventional feedback and feedforward controllers and coordinates them. The designed controller has been simulated and it has been found that the flux waveform tracks the reference fast enough with a satisfactory steady state error. The system has been tested through experiments and experimental results are in good agreement with the simulation results.
Citations
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Journal ArticleDOI
TL;DR: In this paper, a loss estimation technique combining finite element analysis (FEA) and actual core loss measurements is described, and the proposed procedure is shown to improve the accuracy of loss estimation.
Abstract: The complexity of core loss estimation is a serious challenge in the design of high-efficiency electric machines. Current estimation methods based on the Steinmetz equation and loss separation are not accurate enough, even at the rated conditions. This paper describes a loss estimation technique combining finite-element analysis (FEA) and actual core loss measurements. First, flux density waveforms in various parts of the electric machine are determined using FEA. Second, the same waveforms are generated in a wound toroidal core made of the same material as used in the machine. The loss is measured per unit mass, and then the total motor core loss is calculated by integrating the measured W/kg loss values for predefined sections of the motor. These estimation results are compared with those of the Bertotti method. The proposed procedure is shown to improve the accuracy of loss estimation.

11 citations


Cites background from "Design and implementation of a sinu..."

  • ...controlling signal generator that we developed earlier [36]....

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  • ...Given that the flux-controlled signal generator’s bandwidth is 10 kHz [36], the captured waveforms have enough resolution to be rebuilt in the flux-controlled tester....

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  • ...5, the detailed system modeling and control design can be found in [36]....

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Journal ArticleDOI
TL;DR: In this paper , a simple frequency-domain model is proposed based on the linear fitting and two-dimensional interpolation methods for engineering applications, and another two frequencydomain models, respectively, considering and neglecting the excess losses are investigated and compared for the highfrequency iron-loss modeling, which only need low-frequency parameters and contain the physical interpretation to the variation of high-frequency iron loss coefficients with the frequency, ac flux density amplitude, and dc-biased magnetic induction.
Abstract: The high-frequency iron losses caused by sinusoidal flux density variations with frequencies ranging from 2.5 to 40 kHz, amplitudes from 1 to 70 mT, and dc-biased magnetic inductions from 0 to 1.62 T are measured with the dual-transformer system. Then, in this article, a simple frequency-domain model is proposed based on the linear fitting and two-dimensional interpolation methods for engineering applications. In addition, another two frequency-domain models, respectively, considering and neglecting the excess losses are investigated and compared for the high-frequency iron-loss modeling, which only need low-frequency parameters and contain the physical interpretation to the variation of high-frequency iron-loss coefficients with the frequency, ac flux density amplitude, and dc-biased magnetic induction. The iron losses generated by the unipolar and bipolar pulsewidth modulation (PWM) voltages with different switching frequencies and modulation factors are measured to testify the three models. It is shown that the three models in this article are more accurate than the previously proposed one for calculating the PWM-induced iron loss by considering the variation of model parameters with the dc-biased magnetic induction and ac flux density amplitude, especially when silicon steel sheets reach the saturation.

8 citations

Proceedings ArticleDOI
01 Sep 2016
TL;DR: In this paper, a loss estimation technique combining finite element analysis (FEA) and actual core loss measurements is described, in which flux waveforms from various parts of the electric machine are determined using finite element analyses and identical flux density waveforms are generated in a toroidal wound core made out of the same material as is used in the machine.
Abstract: The complexity of core loss estimation is an essential limitation for electric machine design engineers. It is critical to estimate the core losses and reduce them in the design stage to improve the machine efficiency. Current estimation methods based on the Steinmetz equation and loss separation are not accurate enough even at the rated conditions. This work describes a loss estimation technique combining finite element analysis (FEA) and actual core loss measurements. First, flux waveforms from various parts of the electric machine are determined using finite element analysis (FEA), then identical flux density waveforms are generated in a toroidal wound core made out of the same material as is used in the machine. The loss is measured per unit mass, and then the total motor core loss is calculated by combining the measured W/kg loss values for predefined sections of the motor. Estimation results are provided and compared with the Bertotti iron loss and loss surface methods. The proposed method is shown to improve the accuracy of loss estimation.

6 citations


Cites background or methods from "Design and implementation of a sinu..."

  • ...5, the detailed system modeling and control design can be found in [16]....

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  • ...Instead of the conventional voltage controlled signal generator, we use a flux controlling signal generator that we developed earlier [16]....

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Proceedings ArticleDOI
01 Oct 2018
TL;DR: In this article, a single phase DC/Rectified AC/AC (DC/RAC/AC) inverter is analyzed and compared to classical single phase PWM inverters, and the proposed system is superior to the traditional one in terms of efficiency, generated THD with a simplified control structure, and it offers a reduced system size and cost.
Abstract: In this paper, a single phase DC/Rectified AC/AC (DC/RAC/AC) inverter is analyzed and compared to classical single phase PWM inverters. A traditional AC power supply (PS) system consists of a DC/DC converter, a cascaded H-bridge inverter, and a passive filter to generate the sinusoidal output voltage. The presented DC/RAC/AC inverter has a similar structure; however, the control of the cascaded units differ. The presented method generates rectified sine wave at the output of the DC/DC converter unit and the H-bridge inverter alternates the rectified sine wave to generate the full sine wave without having an additional output filter; hence, the switching losses at the H-bridge inverter is limited to the line frequency (50-60 Hz). Moreover, the bulk DC bus capacity at the output of the DC/DC converter is reduced significantly. Therefore, the power consumed by the passive elements are minimized. The circuit modes of operation are analyzed and the system is simulated in Matlab/Simulink environment for both traditional and proposed topologies. Results show that the proposed system is superior to the traditional one in terms of efficiency, generated THD with a simplified control structure, and it offers a reduced system size and cost.

1 citations


Cites background from "Design and implementation of a sinu..."

  • ...Each of these units has a different control structure where the DC/DC converter may be controlled by a simple proportionalintegral voltage or current controller, the H-bridge inverter needs to be controlled with a special control algorithm to generate a low THD sine wave voltage at the output, that should be robust to the disturbances due to the nonlinear loads and has a fast dynamic response to the rapid load variations [1]....

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  • ...The single-phase classical inverter control under nonlinear loading conditions has been a challenge and many respective works can be found in the literature [1], [8], [17], [18]....

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References
More filters
Journal ArticleDOI
TL;DR: The Internal Model Principle is extended to weakly nonlinear systems subjected to step disturbances and reference signals and is shown that, in the frequency domain, the purpose of the internal model is to supply closed loop transmission zeros which cancel the unstable poles of the disturbance andreference signals.

2,613 citations


"Design and implementation of a sinu..." refers background in this paper

  • ...Hence, a repetitive controller, which is based on internal model principle [23], is added to the system to eliminate the periodic distortions....

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Journal ArticleDOI

629 citations


"Design and implementation of a sinu..." refers background in this paper

  • ...The core loss can be calculated by integration of the product of the sensed voltage and the current passing through the primary winding [8, 12,13]....

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Book
24 Mar 2005
TL;DR: In this paper, the authors present a 2D model for Eddy Current Losses in Round Wires and a 1-D model of Ferrite cores. But they do not consider the effect of parasitic capacitance on the performance of the Ferrite core.
Abstract: FUNDAMENTALS OF MAGNETIC THEORY Basic Laws of Magnetic Theory Magnetic Materials Magnetic Circuits References FAST DESIGN APPROACH INCLUDING EDDY CURRENT LOSSES Fast Design Approach Examples Conclusions Appendix 2.A.1: Core Size Scale Law for Ferrites in Non-Saturated Thermal Limited Design Appendix 2.A.2: Eddy Current Losses for Wide Frequency Appendix 2.A.3: MathCAD Example Files References SOFT MAGNETIC MATERIALS Magnetic Core Materials Comparison and Applications of the Core Materials in Power Electronics Losses in Soft Magnetic Materials Ferrite Core Losses with Non-Sinusoidal Voltage Waveforms Wide Frequency Model of Magnetic Sheets Including Hysteresis Effects Appendix 3.A: Power and Impedance of Magnetic Sheets References COIL WINDING AND ELECTRICAL INSULATION Filling Factor Wire Length Physical Aspects of Breakdown Insulation Requirements and Standards Thermal Requirements and Standards Magnetic Component Manufacturing Sheet References EDDY CURRENTS IN CONDUCTORS Introduction Basic Approximations Losses in Rectangular Conductors Quadrature of the Circle Method for Round Conductors Losses of a Current Carrying Round Conductor in 2-D Approach Losses of a Round Conductor in a Uniform Transverse AC Field Low Frequency 2-D Approximation Method for Round Conductors Wide Frequency Method for Calculating Eddy Current Losses in Windings Losses in Foil Windings Losses in Planar Windings Appendix 5.A.1: Eddy Current 1-D Model for Rectangular Conductors Appendix 5.A.2: Low Frequency 2-D Models for Eddy Current Losses in Round Wires Appendix 5.A.3: Field Factor For Inductors References THERMAL ASPECTS Fast Thermal Design Approach (Level 0 Thermal Design) Single Thermal Resistance Design Approach (Level 1 Thermal Design) Classic Heat Transfer Mechanisms Thermal Design Utilizing a Resistance Network Contribution to Heat Transfer Theory of Magnetic Components Transient Heat Transfer Summary Appendix 6.A: Accurate Natural Convection Modeling for Magnetic Components References PARASITIC CAPACITANCES IN MAGNETIC COMPONENTS Capacitance Between Windings: Inter Capacitance Self-Capacitance of a Winding: Intra Capacitance Capacitance Between the Windings and the Magnetic Material Practical Approaches for Decreasing the Effects of Parasitic Capacitances References INDUCTOR DESIGN Air Coils and Related Shapes Inductor Shapes Typical Ferrite Inductor Shapes Fringing in Wire-Wound Inductors with Magnetic Cores Eddy Currents in Inductor Windings Foil Wound Inductors Inductor Types Depending on Application Design Examples of Different Types of Inductors Fringing Coefficients For Gapped-Wire-Wound Inductors Analitical Modeling of Combined Litz Wire-Full Wire Inductors References TRANSFORMER DESIGN Transformer Design in Power Electronics Magnetizing Inductance Leakage Inductance Using Parallel Wires and Litz Wires Interleaved Windings Superimposing Frequency Components Superimposing Modes References OPTIMAL COPPER/CORE LOSS RATIO IN MAGNETIC COMPONENTS Simplified Approach Loss Minimization in the General Case Loss Minimization Without Eddy Current Losses Loss Minimization Including Low-Frequency Eddy Current Losses Summary Examples References MEASUREMENTS Introduction Temperature Measurements Power Losses Measurements Measurement of Inductances Core Loss Measurements Measurement of Parasitic Capacitances Combined Measuring Instruments References APPENDIX A: RMS VALUES OF WAVEFORMS Definitions RMS Values of Some Basic Waveforms RMS Values of Common Waveforms APPENDIX B: MAGNETIC CORE DATA ETD Core Data (Economic Transformer Design Core) EE Core Data Planar EE Core Data ER Core Data UU Core Data Ring Core Data (Toroid Core) P Core Data (Pot Core) PQ Core Data RM Core Data APPENDIX C: COPPER WIRES DATA Round Wire Data American Wire Gauge Data Litz Wire Data APPENDIX D: MATHEMATICAL FUNCTIONS References INDEX

345 citations


"Design and implementation of a sinu..." refers background in this paper

  • ...It is also very much sensitive to phase discrepancy due to 90 phase difference between primary winding current and secondary winding voltage [14, 15]....

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Journal ArticleDOI
TL;DR: In this article, different materials have been tested to gain information on how core losses are influenced by a dc premagnetization, and the Steinmetz graph (SPG) is introduced to calculate core losses under dc bias conditions.
Abstract: The calculation of core losses in inductive components is difficult and has not yet been entirely solved. In particular, it is impossible to predict the influence of a dc premagnetization on the losses without extensive measurements. For this paper, different materials have been tested to gain information on how core losses are influenced by a premagnetization. Measurements on molypermalloy powder, silicon steel, nanocrystalline material and ferrite cores have been performed. The Steinmetz premagnetization graph (SPG) that shows the dependency of the Steinmetz parameters ( , and ) on premagnetization is introduced. This permits the calculation of core losses under dc bias conditions. Such graphs are given for different materials and different operating temperatures. In addition, a detailed description of the test system is given, as high accuracy is crucial.

284 citations


"Design and implementation of a sinu..." refers methods in this paper

  • ...Calculation of the core losses is typically carried out based on Steinmetz equations and parameters [20]....

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Journal ArticleDOI
TL;DR: In this article, the power loss in soft magnetic laminations for generic time dependence of the periodic magnetic polarization J(t) was quantitatively assessed within the theoretical framework of the statistical loss model.
Abstract: We have studied ways of predicting power losses in soft magnetic laminations for generic time dependence of the periodic magnetic polarization J(t). We found that, whatever the frequency and the induction waveform, the loss behavior can be quantitatively assessed within the theoretical framework of the statistical loss model. The prediction requires a limited set of preemptive experimental data, depending on whether or not the arbitrary J(t) waveform is endowed with local slope inversions (i.e., minor hysteresis loops) in its periodic time behavior. In the absence of minor loops, such data reduce, for any peak polarization value J/sub p/, to the loss figures obtained under sinusoidal J(t) at two different frequency values. In the presence of minor loops of semiamplitude J/sub m/, the two-frequency loss experiment should be carried out for both peak polarization values J/sub p/ and J/sub m/. Additional knowledge of the quasi-static major loop, to be used for modeling hysteresis loss, does improve the accuracy of the prediction method. A more general approach to loss in soft magnetic laminations is obtained in this way, the only limitation apparently being the onset of skin effect at high frequencies.

255 citations


"Design and implementation of a sinu..." refers background in this paper

  • ...In most cases the core is saturated to reach required flux density levels beyond 2 T for some cases [21]....

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