EPE Association: EPE 1993 - 45 - Dialogue Session DS3.3: POWER SUPPLIES: MAGNETICS

EPE 1993 - 45 - Dialogue Session DS3.3: POWER SUPPLIES: MAGNETICS
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   DESIGN METHODOLOGY & MODELlNG OF LOW INDUCTANCE PLANAR BUS STRUCTURES
By G. L. Skibinski; D. M. Divan [View]
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Abstract: The minimization of undesirable parasitic inductance becomes vitally important given the dual constraints of higher frequency and higher power levels of modern power converters. This paper investigates the impedance of conventional conductor bus configurations and outlines a planar bus approach that results in extremely low inductance over a wide range of operating frequencies.

   MINIMUM LOSS DESIGN OF A 100 kHz INDUCTOR WITH FOIL WINDINGS
By A. Nysveen; M. Hernes [View]
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Abstract: In high current, high frequency inductors and transformers foil windings will be competitive with other types like litz wire if they are properly designed. Effective loss calculation tools presented by Dowell [2], Jongsma [3] and Carsten [4] gives good control of the losses in foil windings used in transformers. In an inductor, problems arise due to the needed air gaps. A minimum loss design of a 100 kHz inductor with foil windings using a multi air gap approach is presented. In the design process finite element eddy current computations have been used extensively. A prototype has been constructed and tested. The inductor is supposed to be used in a 20 kVA Dual-Active-Bridge Inverter. The required inductance is 5 μH. In the final design, a multi air gap solution with 16 air gaps is used keeping the winding losses as low as 35 W at 75 A rated current. The additional losses rising from the fringe field near the air gaps is only 7 W at rated current. Our tests on the inductor verifies that all sources of high frequency winding losses are well under control.

   MODELLING OF DYNAMIC LOSSES IN MAGNETIC MATERIAL
By A. Brockmeyer; L. Schülting [View]
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Abstract: This paper shows that the common rnethods of loss calculation for ferro- and ferrimagnetic materials fail in the case of non-sinusoidal magnetic fields and dc-premagnetization appearing in new converter topologies. For this reason a new dynamic calculation model based on the static Jiles-Atherton model of ferromagnetic hysteresis is presented. A good accordance between calculations of the dynamic model and experimental results is shown for any dynamic field condition.

   SINGLE TURN WORK COIL AND INTEGRATED MATCHING TRANSFORMER FOR MEDIUM AND HlGH FREQUENCY INDUCTION HEATING
By S. M. Swart; J. A. Ferreira [View]
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Abstract: A single turn work coil with an integrated matching transformer for medium and high frequency induction heating application is proposed. The secondary of the transformer is an extension of the work coil, and the primary is situated within the hollow, water cooled secondary. Advantages of the construction include: low series (leakage) inductance of the coaxial transformer; liquid cooling of work coil, coaxial transformer and switching devices. Higher efficiency of work coil is achieved by low leakage inductance, which gives better coupling between the converter and the workpiece. Simulation results compare the multi- and single turn coils with respect to work coil efficiency and investigate the difference in current distributions. Experimental results are presented, using a series resonant converter with hybrid analogue and digital controller.

   RESONANT CONVERTER CONTROLLED BY VARIABLE LEAKAGE INDUCTANCE IN THE TRANSFORMER (L.I.C.)
By A. M. Pernia; F. Nuño; E. L. Corominas; J. M. Lopera [View]
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Abstract: In this paper a new method of control that permits the regulation of the output characteristics in a resonant converter, maintaining constant the switching frequency is presented. The control variable used in the regulation of the converter is the continuous variation of the transformer leakage inductance.
The main advantages of this control method are the following:
- The design of all components in the converter at only one frequency.
- Facility of parallel operation mode and synchronization.
- Possibility to extend this control method to any resonant topology.

   USING A TAPPED INDUCTOR FOR REDUCING CONDUCTION LOSSES IN A SOFT-SWITCHING PWM DC-DC CONVERTER
By S. Hamada; M. Michihira; N. Nakaoka [View]
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Abstract: An improved soft-switching PWM full-bridge DC-DC converter is presented. This employs a tapped inductor for low-pass filter to minimize a circulating current flowing through the transformer and switching devices. By using the tapped inductor and a saturable reactor(s), the converter achieves soft-switching with both low commutating and low circulating currents resulting in low switching and conduction losses. The effective performance of the converter is experimentally confirmed with a 100kHz-500W breadbord.

EPE 1993 - 45 - Dialogue Session DS3.3: POWER SUPPLIES: MAGNETICS
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1993 - Conference > EPE 1993 - 45 - Dialogue Session DS3.3: POWER SUPPLIES: MAGNETICS
	[return to parent folder]

	DESIGN METHODOLOGY & MODELlNG OF LOW INDUCTANCE PLANAR BUS STRUCTURES By G. L. Skibinski; D. M. Divan	[View] [Download]
Abstract: The minimization of undesirable parasitic inductance becomes vitally important given the dual constraints of higher frequency and higher power levels of modern power converters. This paper investigates the impedance of conventional conductor bus configurations and outlines a planar bus approach that results in extremely low inductance over a wide range of operating frequencies.

	MINIMUM LOSS DESIGN OF A 100 kHz INDUCTOR WITH FOIL WINDINGS By A. Nysveen; M. Hernes	[View] [Download]
Abstract: In high current, high frequency inductors and transformers foil windings will be competitive with other types like litz wire if they are properly designed. Effective loss calculation tools presented by Dowell [2], Jongsma [3] and Carsten [4] gives good control of the losses in foil windings used in transformers. In an inductor, problems arise due to the needed air gaps. A minimum loss design of a 100 kHz inductor with foil windings using a multi air gap approach is presented. In the design process finite element eddy current computations have been used extensively. A prototype has been constructed and tested. The inductor is supposed to be used in a 20 kVA Dual-Active-Bridge Inverter. The required inductance is 5 μH. In the final design, a multi air gap solution with 16 air gaps is used keeping the winding losses as low as 35 W at 75 A rated current. The additional losses rising from the fringe field near the air gaps is only 7 W at rated current. Our tests on the inductor verifies that all sources of high frequency winding losses are well under control.

	MODELLING OF DYNAMIC LOSSES IN MAGNETIC MATERIAL By A. Brockmeyer; L. Schülting	[View] [Download]
Abstract: This paper shows that the common rnethods of loss calculation for ferro- and ferrimagnetic materials fail in the case of non-sinusoidal magnetic fields and dc-premagnetization appearing in new converter topologies. For this reason a new dynamic calculation model based on the static Jiles-Atherton model of ferromagnetic hysteresis is presented. A good accordance between calculations of the dynamic model and experimental results is shown for any dynamic field condition.

	SINGLE TURN WORK COIL AND INTEGRATED MATCHING TRANSFORMER FOR MEDIUM AND HlGH FREQUENCY INDUCTION HEATING By S. M. Swart; J. A. Ferreira	[View] [Download]
Abstract: A single turn work coil with an integrated matching transformer for medium and high frequency induction heating application is proposed. The secondary of the transformer is an extension of the work coil, and the primary is situated within the hollow, water cooled secondary. Advantages of the construction include: low series (leakage) inductance of the coaxial transformer; liquid cooling of work coil, coaxial transformer and switching devices. Higher efficiency of work coil is achieved by low leakage inductance, which gives better coupling between the converter and the workpiece. Simulation results compare the multi- and single turn coils with respect to work coil efficiency and investigate the difference in current distributions. Experimental results are presented, using a series resonant converter with hybrid analogue and digital controller.

	RESONANT CONVERTER CONTROLLED BY VARIABLE LEAKAGE INDUCTANCE IN THE TRANSFORMER (L.I.C.) By A. M. Pernia; F. Nuño; E. L. Corominas; J. M. Lopera	[View] [Download]
Abstract: In this paper a new method of control that permits the regulation of the output characteristics in a resonant converter, maintaining constant the switching frequency is presented. The control variable used in the regulation of the converter is the continuous variation of the transformer leakage inductance. The main advantages of this control method are the following: - The design of all components in the converter at only one frequency. - Facility of parallel operation mode and synchronization. - Possibility to extend this control method to any resonant topology.

	USING A TAPPED INDUCTOR FOR REDUCING CONDUCTION LOSSES IN A SOFT-SWITCHING PWM DC-DC CONVERTER By S. Hamada; M. Michihira; N. Nakaoka	[View] [Download]
Abstract: An improved soft-switching PWM full-bridge DC-DC converter is presented. This employs a tapped inductor for low-pass filter to minimize a circulating current flowing through the transformer and switching devices. By using the tapped inductor and a saturable reactor(s), the converter achieves soft-switching with both low commutating and low circulating currents resulting in low switching and conduction losses. The effective performance of the converter is experimentally confirmed with a 100kHz-500W breadbord.