The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform

Drago Dolinar - One of the best experts on this subject based on the ideXlab platform.

  • Iron Core Power Losses of an Medium Frequency Resistance Spot Welding Transformer
    2011
    Co-Authors: Martin Petrun, Drago Dolinar
    Abstract:

    This paper deals with power losses in a laminated magnetic Core of a medium frequency resistance spot welding transformer (RSWT). The aim of this work is to evaluate the Iron Core power losses of an RSWT for Iron Cores with different lamination thickness and for different operating temperatures. This evaluation is used for the advanced design of RSWTs. For determination of Iron Core losses a laboratory measuring system is used. Further, an experimental method for separation of Iron Core losses is presented. The proposed method separates Iron Core losses into two components; hysteresis losses and dynamic losses. The results are validated with a dynamic model of the RSWT Iron Core.

  • Prevention of Iron Core Saturation in Multi-Winding Transformers for DC-DC Converters
    IEEE Transactions on Magnetics, 2010
    Co-Authors: Gorazd Stumberger, B. Klopčič, Klemen Deželak, Drago Dolinar
    Abstract:

    This paper deals with prevention of saturation in the Iron Core of a multi-winding transformer. It is a substantial part of dc-dc converters used in resistance spot welding systems. The discussed resistance spot welding system consists of a semiconductor input converter, a single-phase welding transformer with one primary coil and two secondary coils, and a full-wave output rectifier connected to the transformer's secondary coils. The paper shows that the interaction among magnetically nonlinear behavior of the Iron Core combined with unbalanced parameters of the circuits with the two transformer's secondary coils can cause Iron Core saturation even when elements connected to coils are passive elements. The first part of the paper focuses on analysis of saturation phenomena in multi-winding transformers. It is performed on specially designed laboratory transformer composed of the Iron Core in the form of two C-shaped segments and modular coils used to form the single-coil primary winding and two-coil secondary winding. Knowledge acquired on the laboratory transformer is applied to develop two different solutions for active prevention of the Iron Core saturation in multi-winding welding transformers. Both solutions are presented in the second part of the paper.

  • detecting saturation level in the Iron Core of a welding transformer in a resistance spot welding system
    Journal of Magnetism and Magnetic Materials, 2008
    Co-Authors: Klemen Deželak, B. Klopčič, Gorazd Stumberger, Drago Dolinar
    Abstract:

    Abstract This paper deals with saturation level detection in the Iron Core of a welding transformer (WT), which is a part of the resistance direct current spot-welding system. The saturation level in the Iron Core must be detected and controlled in order to utilize the Iron Core. This work evaluates four different methods appropriate for detecting the saturation level in the transformer's Iron Core. These methods actually detect the instant the Iron Core starts to become saturated and generate those signals used during control, in order to prevent saturation. In method I a flux linkage value is used to detect the saturation level. In method II the partial derivative of the flux linkage versus magnetomotive force characteristic is applied. Method III uses the ratio between the induced voltages measured by the probe coil wound around the Iron Core and the probe coil placed on the surface of the Iron Core. Method IV is similar to method III. The flux measurement with a surface mounted probe coil as applied in method III is replaced in method IV by flux density measurement using a Hall sensor placed close to the Iron Core's surface. All the methods presented are evaluated by measurements performed on the Iron Core of an industrial 120 kVA spot WT.

  • Determining Magnetically Nonlinear Characteristics of Transformers and Iron Core Inductors by Differential Evolution
    IEEE Transactions on Magnetics, 2008
    Co-Authors: Gorazd Stumberger, B Polajzer, Bojan Štumberger, Sebastijan Seme, Drago Dolinar
    Abstract:

    This paper deals with the differential evolution (DE)-based method for determining the magnetically nonlinear Iron Core characteristics of transformers and Iron Core inductors. The unknown Iron Core characteristic, approximated by the sum of exponential functions, is included in a dynamic model of the tested device. The approximation function parameters are determined by DE. The optimization objective is the best possible agreement between the measured and the dynamic model calculated currents in the time and frequency domains. Using the measured inrush currents and corresponding voltages, the magnetically nonlinear characteristic can be determined over a broad operational range. The inclusion of Iron Core characteristic, as determined by the proposed method, in the transformer dynamic model gives very good agreement between the measured and calculated currents in both transient and steady states.

  • a three phase Core type transformer Iron Core model with included magnetic cross saturation
    IEEE International Magnetics Conference, 2006
    Co-Authors: Matjaž Dolinar, Gorazd Stumberger, Drago Dolinar, B Polajzer, Jozef Ritonja
    Abstract:

    The behavior of a power transformer (PT) depends considerably on the properties of the magnetically nonlinear Iron Core. This paper deals with the modeling of a three-phase, three-limb power transformer laminated Iron Core. The proposed Iron Core model is given by the corresponding partial derivatives of measured flux linkage characteristics. The magnetically nonlinear characteristics of flux linkages are determined by the controlled simultaneous magnetic excitation of all three limbs. This enables determination of magnetic cross couplings between different limbs, due to the saturation. The obtained Iron Core model integrated in the circuit model of PT is compared to the classical saturated Iron Core model without cross couplings, by analyzing the transient behavior of an unsymmetrically excited transformer. The numerical results obtained by the proposed Iron Core model agree with the measured results much better than those obtained by the existing nonlinear Iron Core model known from literature

Gorazd Stumberger - One of the best experts on this subject based on the ideXlab platform.

  • Prevention of Iron Core Saturation in Multi-Winding Transformers for DC-DC Converters
    IEEE Transactions on Magnetics, 2010
    Co-Authors: Gorazd Stumberger, B. Klopčič, Klemen Deželak, Drago Dolinar
    Abstract:

    This paper deals with prevention of saturation in the Iron Core of a multi-winding transformer. It is a substantial part of dc-dc converters used in resistance spot welding systems. The discussed resistance spot welding system consists of a semiconductor input converter, a single-phase welding transformer with one primary coil and two secondary coils, and a full-wave output rectifier connected to the transformer's secondary coils. The paper shows that the interaction among magnetically nonlinear behavior of the Iron Core combined with unbalanced parameters of the circuits with the two transformer's secondary coils can cause Iron Core saturation even when elements connected to coils are passive elements. The first part of the paper focuses on analysis of saturation phenomena in multi-winding transformers. It is performed on specially designed laboratory transformer composed of the Iron Core in the form of two C-shaped segments and modular coils used to form the single-coil primary winding and two-coil secondary winding. Knowledge acquired on the laboratory transformer is applied to develop two different solutions for active prevention of the Iron Core saturation in multi-winding welding transformers. Both solutions are presented in the second part of the paper.

  • detecting saturation level in the Iron Core of a welding transformer in a resistance spot welding system
    Journal of Magnetism and Magnetic Materials, 2008
    Co-Authors: Klemen Deželak, B. Klopčič, Gorazd Stumberger, Drago Dolinar
    Abstract:

    Abstract This paper deals with saturation level detection in the Iron Core of a welding transformer (WT), which is a part of the resistance direct current spot-welding system. The saturation level in the Iron Core must be detected and controlled in order to utilize the Iron Core. This work evaluates four different methods appropriate for detecting the saturation level in the transformer's Iron Core. These methods actually detect the instant the Iron Core starts to become saturated and generate those signals used during control, in order to prevent saturation. In method I a flux linkage value is used to detect the saturation level. In method II the partial derivative of the flux linkage versus magnetomotive force characteristic is applied. Method III uses the ratio between the induced voltages measured by the probe coil wound around the Iron Core and the probe coil placed on the surface of the Iron Core. Method IV is similar to method III. The flux measurement with a surface mounted probe coil as applied in method III is replaced in method IV by flux density measurement using a Hall sensor placed close to the Iron Core's surface. All the methods presented are evaluated by measurements performed on the Iron Core of an industrial 120 kVA spot WT.

  • Determining Magnetically Nonlinear Characteristics of Transformers and Iron Core Inductors by Differential Evolution
    IEEE Transactions on Magnetics, 2008
    Co-Authors: Gorazd Stumberger, B Polajzer, Bojan Štumberger, Sebastijan Seme, Drago Dolinar
    Abstract:

    This paper deals with the differential evolution (DE)-based method for determining the magnetically nonlinear Iron Core characteristics of transformers and Iron Core inductors. The unknown Iron Core characteristic, approximated by the sum of exponential functions, is included in a dynamic model of the tested device. The approximation function parameters are determined by DE. The optimization objective is the best possible agreement between the measured and the dynamic model calculated currents in the time and frequency domains. Using the measured inrush currents and corresponding voltages, the magnetically nonlinear characteristic can be determined over a broad operational range. The inclusion of Iron Core characteristic, as determined by the proposed method, in the transformer dynamic model gives very good agreement between the measured and calculated currents in both transient and steady states.

  • a three phase Core type transformer Iron Core model with included magnetic cross saturation
    IEEE International Magnetics Conference, 2006
    Co-Authors: Matjaž Dolinar, Gorazd Stumberger, Drago Dolinar, B Polajzer, Jozef Ritonja
    Abstract:

    The behavior of a power transformer (PT) depends considerably on the properties of the magnetically nonlinear Iron Core. This paper deals with the modeling of a three-phase, three-limb power transformer laminated Iron Core. The proposed Iron Core model is given by the corresponding partial derivatives of measured flux linkage characteristics. The magnetically nonlinear characteristics of flux linkages are determined by the controlled simultaneous magnetic excitation of all three limbs. This enables determination of magnetic cross couplings between different limbs, due to the saturation. The obtained Iron Core model integrated in the circuit model of PT is compared to the classical saturated Iron Core model without cross couplings, by analyzing the transient behavior of an unsymmetrically excited transformer. The numerical results obtained by the proposed Iron Core model agree with the measured results much better than those obtained by the existing nonlinear Iron Core model known from literature

  • Magnetically nonlinear and anisotropic Iron Core model of synchronous reluctance motor
    Journal of Magnetism and Magnetic Materials, 2002
    Co-Authors: Gorazd Stumberger, Bojan Štumberger, Drago Dolinar
    Abstract:

    The magnetically nonlinear and anisotropic Iron Core model of a synchronous reluctance motor (SRM) is presented. The Iron Core model is given by the current-dependent flux linkages and their partial derivatives. It is included in a dynamic SRM model and confirmed through the comparison of measured and calculated results in the case of current-controlled linear synchronous reluctance servomotor.

Klemen Deželak - One of the best experts on this subject based on the ideXlab platform.

  • Prevention of Iron Core Saturation in Multi-Winding Transformers for DC-DC Converters
    IEEE Transactions on Magnetics, 2010
    Co-Authors: Gorazd Stumberger, B. Klopčič, Klemen Deželak, Drago Dolinar
    Abstract:

    This paper deals with prevention of saturation in the Iron Core of a multi-winding transformer. It is a substantial part of dc-dc converters used in resistance spot welding systems. The discussed resistance spot welding system consists of a semiconductor input converter, a single-phase welding transformer with one primary coil and two secondary coils, and a full-wave output rectifier connected to the transformer's secondary coils. The paper shows that the interaction among magnetically nonlinear behavior of the Iron Core combined with unbalanced parameters of the circuits with the two transformer's secondary coils can cause Iron Core saturation even when elements connected to coils are passive elements. The first part of the paper focuses on analysis of saturation phenomena in multi-winding transformers. It is performed on specially designed laboratory transformer composed of the Iron Core in the form of two C-shaped segments and modular coils used to form the single-coil primary winding and two-coil secondary winding. Knowledge acquired on the laboratory transformer is applied to develop two different solutions for active prevention of the Iron Core saturation in multi-winding welding transformers. Both solutions are presented in the second part of the paper.

  • detecting saturation level in the Iron Core of a welding transformer in a resistance spot welding system
    Journal of Magnetism and Magnetic Materials, 2008
    Co-Authors: Klemen Deželak, B. Klopčič, Gorazd Stumberger, Drago Dolinar
    Abstract:

    Abstract This paper deals with saturation level detection in the Iron Core of a welding transformer (WT), which is a part of the resistance direct current spot-welding system. The saturation level in the Iron Core must be detected and controlled in order to utilize the Iron Core. This work evaluates four different methods appropriate for detecting the saturation level in the transformer's Iron Core. These methods actually detect the instant the Iron Core starts to become saturated and generate those signals used during control, in order to prevent saturation. In method I a flux linkage value is used to detect the saturation level. In method II the partial derivative of the flux linkage versus magnetomotive force characteristic is applied. Method III uses the ratio between the induced voltages measured by the probe coil wound around the Iron Core and the probe coil placed on the surface of the Iron Core. Method IV is similar to method III. The flux measurement with a surface mounted probe coil as applied in method III is replaced in method IV by flux density measurement using a Hall sensor placed close to the Iron Core's surface. All the methods presented are evaluated by measurements performed on the Iron Core of an industrial 120 kVA spot WT.

B. Klopčič - One of the best experts on this subject based on the ideXlab platform.

  • Prevention of Iron Core Saturation in Multi-Winding Transformers for DC-DC Converters
    IEEE Transactions on Magnetics, 2010
    Co-Authors: Gorazd Stumberger, B. Klopčič, Klemen Deželak, Drago Dolinar
    Abstract:

    This paper deals with prevention of saturation in the Iron Core of a multi-winding transformer. It is a substantial part of dc-dc converters used in resistance spot welding systems. The discussed resistance spot welding system consists of a semiconductor input converter, a single-phase welding transformer with one primary coil and two secondary coils, and a full-wave output rectifier connected to the transformer's secondary coils. The paper shows that the interaction among magnetically nonlinear behavior of the Iron Core combined with unbalanced parameters of the circuits with the two transformer's secondary coils can cause Iron Core saturation even when elements connected to coils are passive elements. The first part of the paper focuses on analysis of saturation phenomena in multi-winding transformers. It is performed on specially designed laboratory transformer composed of the Iron Core in the form of two C-shaped segments and modular coils used to form the single-coil primary winding and two-coil secondary winding. Knowledge acquired on the laboratory transformer is applied to develop two different solutions for active prevention of the Iron Core saturation in multi-winding welding transformers. Both solutions are presented in the second part of the paper.

  • detecting saturation level in the Iron Core of a welding transformer in a resistance spot welding system
    Journal of Magnetism and Magnetic Materials, 2008
    Co-Authors: Klemen Deželak, B. Klopčič, Gorazd Stumberger, Drago Dolinar
    Abstract:

    Abstract This paper deals with saturation level detection in the Iron Core of a welding transformer (WT), which is a part of the resistance direct current spot-welding system. The saturation level in the Iron Core must be detected and controlled in order to utilize the Iron Core. This work evaluates four different methods appropriate for detecting the saturation level in the transformer's Iron Core. These methods actually detect the instant the Iron Core starts to become saturated and generate those signals used during control, in order to prevent saturation. In method I a flux linkage value is used to detect the saturation level. In method II the partial derivative of the flux linkage versus magnetomotive force characteristic is applied. Method III uses the ratio between the induced voltages measured by the probe coil wound around the Iron Core and the probe coil placed on the surface of the Iron Core. Method IV is similar to method III. The flux measurement with a surface mounted probe coil as applied in method III is replaced in method IV by flux density measurement using a Hall sensor placed close to the Iron Core's surface. All the methods presented are evaluated by measurements performed on the Iron Core of an industrial 120 kVA spot WT.

David L. Trumper - One of the best experts on this subject based on the ideXlab platform.

  • double sided linear Iron Core fine tooth motor for low acoustic noise and high acceleration
    IEEE-ASME Transactions on Mechatronics, 2019
    Co-Authors: Jun Young Yoon, Jeffrey H. Lang, David L. Trumper
    Abstract:

    This paper presents the design, construction, and testing of a low-noise high-force double-sided linear Iron-Core motor for high-precision and high-throughput system applications such as in semiconductor photo-lithography machines. Linear Iron-Core permanent-magnet motors can emit significant vibration and acoustic noise due to high spatial-frequency force harmonics, causing harmonic vibrations of a moving stage. As a design solution to such motor noise, we presented magnetic designs of a new linear Iron-Core motor having fine teeth, narrow slots with high aspect ratio, and a moving skewed Halbach magnet array in an earlier article. In this paper, we present a further noise reduction method of directly canceling out the normal-direction force harmonics by using a symmetric double-sided motor. In the conventional Iron-Core motor design, the double-sided configuration achieves more than 70% overall noise reduction relative to a single-sided configuration. The new fine-tooth motor even in the single-sided configuration reduces the acoustic noise further by 79% from the double-sided conventional motor, which corresponds to 95% noise reduction compared to the single-sided conventional motor. By configuring the fine-tooth motors in a double-sided manner, we achieve more than 35 dB noise reduction in sound pressure level during acceleration regions, which corresponds to a 50:1 reduction in units of Pascals. In this paper, we also present the high-shear-stress performance of the double-sided fine-tooth motor, achieving 8.2 G with a 12.3 kg stage using only two magnet pole pairs each for the upper and lower motors.

  • High-force linear Iron-Core fine-tooth motor
    2017 11th International Symposium on Linear Drives for Industry Applications (LDIA), 2017
    Co-Authors: Jun Young Yoon, Jeffrey H. Lang, David L. Trumper
    Abstract:

    This paper presents the design and testing of a high force linear fine-tooth Iron-Core permanent magnet motor. We present the design and experimental results in comparison with a commercially-available Iron-Core linear motor. Our new fine-tooth motor shows predicted shear stress improvements of 28 % at the prototype practical power level of 10 W/mm and 85 % at an anticipated ultimate root mean square (RMS) current density limit in the coil wires of 50 A/mm2, relative to the conventional Iron-Core motor. This force performance of our new motor is also experimentally validated. The new motor shows strong potential for industry applications requiring precision motion along with high speed of production, such as in photo-lithography machines.