EPE Association: EPE 2017 - DS1c: Passive Components

EPE 2017 - DS1c: Passive Components
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2017 ECCE Europe - Conference > EPE 2017 - Topic 01: Devices, Packaging and System Integration > EPE 2017 - DS1c: Passive Components

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   A Comparative Study of Output Filter Efficiency and Power Density in Single-Phase Grid-Tied Inverter Using Continuous or Discontinuous Current Mode Operations
By RENE ALEXANDER BARRERA-CARDENAS [View]
[Download]

Abstract: This paper introduces the optimal design of a output filter for a Single-Phase Grid-Tied Inverter considering Continuous and Discontinuous Conduction Modes (CCM and DCM). An optimal design procedure has been proposed, which enables to consider different technologies on the inductor design. Technologies on magnetic materials and wire types has been considered and their benefits for CCM and DCM solutions have been detected. It has been found that Powder magnetic materials allow to improve the Volume-Loss trade-off on output filters when DCM operation is considered for Single-Phase Inverters.

   A High-Frequency Semi Co-Axial Transformer With High Insulation Voltage
By Matthijs HEUVELMANS [View]
[Download]

Abstract: A semi co-axial transformer concept is described which can be used to transfer energy across a relativelyhigh potential difference without using potting components. The intended purpose of the design is to pro-vide electrically insulated power for heating up the semiconductor devices in a double-pulse test circuitoperating at several kilovolts. Because of the requirement of handling the large potential difference, alarge leakage inductance is anticipated and the LLC topology is used to solve the issue of excessive volt-age drop. The transformer is implemented using ring cores and a primary winding which is led throughthe center inside a shielding tube which in turn has several millimetres of insulation on the outside. Apartfrom the aspects of insulation, this work deals with the choice of core material, wire thickness and type,determining the transformer properties, including the magnetic and electrical losses. Distinctive featuresin the design are the configuration which approaches some of the properties of a coaxial configurationand the inclusion of a thick metallic shield. Results show that a good prediction of the performance canbe achieved using relatively simple techniques.

   Comparative Analysis of Three-Phase and Single-Phase Inductance Measurements of the Three-Phase Inductor
By Radoslaw JEZ [View]
[Download]

Abstract: Three-phase inductors are crucial components for power electronic devices. The most typical measurement process of such inductors bases on three-phase power supply, but it causes many difficulties, especially in industrial or manufacturing tests. The proposed alternative is an implementation of single-phase measurements to three-phase inductors. This approach is discussed in the publication.

   Controlled Magnetic Devices in Power Electronic Applications
By Peter ZACHARIAS [View]
[Download]

Abstract: Almost all power electronic converters require magnetic devices and some properties of the converters can be controlled with magnetics. New magnetic materials enable implementation of magnetic control of converters also in high switching frequency applications. The presented paper gives an overview about controllability of magnetic devices in theory and practice, simulation approaches and examples. The focus is on electrically controllable magnetic devices. This means that an additional control winding is wound on or integrated into the magnetic core of the device. This additional winding is used to control the inductive behavior of the device by injecting a current. The different basic control approaches of magnetic devices are explained theoretically and demonstrated experimentally by laboratory prototypes. Several controllable magnetic devices were tested in order to evaluate the applicability of the different control methods. The control techniques were demonstrated also with different core materials to address different applications. Especially ferromagnetic alloys and ferrite materials are in focus of the investigation. Moreover, first approaches for the modelling and simulation of controllable magnetic devices are given in the paper.

   Design method for the minimization of common-mode inductor volume taking into account saturation issues in EMI filters for variable duty cycle applications
By Bilel ZAIDI [View]
[Download]

Abstract: The subject of this paper is to propose a design method of the EMI filters that allows to minimize the volume of the common-mode inductor with consideration of core saturation issues. Inductor volume depends not only on its inductance value, but also on the relationship between the filter and its environment which can saturate the magnetic material due to many parameters, especially when the filter resonance frequency Fr is higher than the converter switching frequency Fs. One of these parameters is the converter duty cycle D. This study explains why it is more desirable to set Fr below Fs in order to reduce the coupled inductor volume while increasing the filter performances.

   Development of a magnetic circuit component to predict magnetic waveforms and core losses in a circuit type software
By Alexis FOUINEAU [View]
[Download]

Abstract: Medium frequency transformers are an essential part of new energy conversion systems, and are very often subject to non-sinusoidal excitation. Therefore, usual methods to represent magnetic materials behavior inside transformers with electrical equivalent scheme are very limited in this case. This paper focuses on the development of a new model based on the loss separation method. This model is implemented in a circuit simulation software with the VHDL-AMS modeling language to represent the behavior of a flux tube: non-linearity, hysteresis and losses. It allows to obtain relevant results for any excitation waveform as the model is temporal. The developed model was compared with experimental results on a small-scale nanocrystalline transformer prototype and it remains very accurate regarding the hysteresis cycle shape and core losses over a wide frequency range, and also for different waveforms.

   Fundamental Investigation of very fast Transients in Power-Electronic Winding for Solid-State Transformers
By Tobias APPEL [View]
[Download]

Abstract: There are problems with insulation failures in high-voltage transformers due to fast transient voltages. Within novel Solid-State Transformers (SST) this problem exists constitutionally because of the SSTs rectangular working voltages. Experiments and simulations have been performed to get accurate understanding of the phenomena. The results and theories are discussed in this paper.

   High power density DC/DC-converter using coupled inductors
By Patrick DECK [View]
[Download]

Abstract: This paper presents a high power density coupled tape-wound inductor consisting of nano-crystallinematerial used in a DC/DC converter. In a first step the comparison of the 2-phase coupled inductor(CI) with the 2-phase interleaved converter (SII) is presented. Second step is designing the CI rho/eta-pareto analysis. To test the device a high power density SiC-converter is designed. The experimentallytested prototype is operating at Vh = 400V, i = 100A, fs = 90kHz, aimed at an overall power density ofrho = 40kW/l.

   Hybrid Magnetics and Power Converter Applications
By Wai Keung MO [View]
[Download]

Abstract: A hybrid magnetic approach, consisting of merging two different magnetic core properites such as ferrite and ironpowder cores together, is an effective solution for power converter applications. It can provide similar magnetic properties to that of magnetic powder cores but showing less copper loss than powder cores. Additionally, the relatively large inductance at low loading current is an excellent way to minimize total power loss, achieving high efficiency. In order to prevent ferrite core saturation, placing an effective air gap within the ferrite core is a key method to obtain optimum hybrid magnetic performance.

   Hysteresis modelling of a medium frequency single-phase transformer
By Piotr DWORAKOWSKI [View]
[Download]

Abstract: The article describes a feedback Preisach hysteresis model equivalent circuit implementation of a medium frequency single-phase transformer being a part of a high power and high efficiency DC-DC converter. The macroscopic models of magnetic hysteresis are introduced and the feedback Preisach model is selected for further analysis. The hysteresis model is developed for a prototype transformer and the hysteresis loops are compared against a measurement. The equivalent circuit implementation of the hysteresis model is proposed and analysed. The equivalent circuit model is validated in no load operation and compared with a measurement.

   Impacts on the Current Distribution of Metal Oxide Varistors for Overvoltage Protection in IGBT Modules
By Fabian HOHMANN [View]
[Download]

Abstract: This paper presents impacts of the characteristics of Metal Oxide Varistors (MOV) for selecting and calculating the suited amount of MOVs to enable semiconductors to act as DC-Breakers. The specific structure of zinc oxide shows dependencies in its voltage and current characteristics which exhibits a hysteresis.

   Integrated magnetic element for improving efficiency of LLC resonant converter
By Cezary WOREK [View]
[Download]

Abstract: This paper presents a design and construction of an integrated magnetic element IME to achieve high efficiency and high power density in 1250 W LLC resonant converter. The advantage of the presented LLC-type resonant converter structure, with integrated magnetic element (IME) is the possibility of easy adaptation to various power levels. Superposition of two magnetic inductions oriented antiparallelly in the chosen areas of IME allows reduction of the volume required for inductive elements, increased coefficient of transferred power to volume and reduction of parasitic capacitances. In addition, due to a nearly sinusoidal shapes of currents in the resonant circuit, the losses due to operating frequency are also minimal. Thus, the described DC-DC resonant converter dedicated for lighting application based on special integrated magnetic element (IME) has achieved requirements concerning low-cost and high-efficiency. The magnetic component can utilize one or two pairs of the cores. Scalable core construction allows to build a power supply with power range from 300W to 1500W.

   Novel Insulation Concept for an MV Dry-Cast Medium-Frequency Transformer
By Thomas GRADINGER [View]
[Download]

Abstract: A 240 kVA, 10 kHz medium-frequency transformer (MFT) to be used in MV DC/DC conversion was developed. The transformer has separately dry-cast windings and was designed for DC system voltages up to 50 kV. For dimensioning and optimization, a MATLAB-based tool was used, containing fast models for electromagnetic, insulation, and thermal design, as well as losses in windings and core. Starting from a small set of primary parameters, a particular MFT design is completed, and an optimization parameter is determined, containing specific MFT cost and size. Automatic optimization is achieved by sweeping over the space of primary parameters, using meshes of increasing resolution. The optimal MFT design was verified and the field grading analyzed in more detail using 3-d electrostatic simulation. Prototypes were built and the insulation was experimentally verified by 70 kV AC and 150 kV lightning impulse tests. Careful field grading and insulation of the HV connections are key to avoid discharges in air up to the PD test voltage, flashovers, and discharges to the nearby grounded components of the MFT. The experimental verification included thermal tests that demonstrated the attractive combination of small air-insulation distances and efficient air cooling of the chosen MFT concept.

   OBSERVATION OF ARCING INSIDE A FUSE UNDER CAPACITOR-DISCHARGE USING 1 MILLION FRAMES PER SECOND X-RAY IMAGING
By Jean-Louis GELET [View]
[Download]

Abstract: Despite their apparent banality, fuses are still obligatory components in modern electrical equipment by offering the ultimate protection against faulty conditions and guaranteeing the disconnection of the damaged legs. Melting of the conducting wire is not as intricate as cancellation of the current by the electrical arc occurring during fuse-operation. Generations of engineers and scientists investigated for understanding complex phenomena related to interaction between arc and sand arranged as energy absorbent.Most of their observations have been run post mortem. All had the dream to make the actual movie of an arc inside the fuse-envelop. A few of them approached this fantasy by using diverting ways such as spectroscopy through a window or matrix of magnetic sensors. Unfortunately that gave deficient information. For the first time a team from MERSEN, together with researchers from SIMAP-laboratory at the University of Grenoble took profit of the facilities of the ESRF-synchrotron also in Grenoble to proceed to ultra-fast X-ray imaging of the arc inside the envelop. Observations up to 1,000,000 frames per second have been performed. Analysis of the records brings valuable information about the arc in the fuse and allows adjusting models, with a major interest for very fast operation under high di/dt.

   Optimal inductor winding geometries for minimizing winding loss in gapped inductor designs
By Wai Keung MO [View]
[Download]

Abstract: This paper summarizes geometrical effects on inductor winding loss based on fixed and variable wire diametermethods as well as core gap effects. Relevant AC and DC winding resistance equations are derived and an effective inductor design method is given to consider the ratio of alternating to direct current and ratio of skin depth to wire radius r. The core gap effect on the ac winding resistance can be minimized by increasing the distance far away from the gap, however thedc winding resistance will increase. Hence the optimal distance results in the minimum total winding resistance. Finally, a new concept of a two step core gap solution is verified by FEA simulation showing the further winding loss improvement by the smart design method of core gap geometries.

   Thermal Behaviour of DC Power Inductor of 600 kW Power Supply for Particle Accelerators
By Danijel MATEJEVIC [View]
[Download]

Abstract: The paper investigates a thermal behaviour of a DC inductor deployed in a 600 kW power converter for particle accelerators. The inductor is manufactured from electrical steel core and two magnetically coupled windings with integrated air ducts for enhanced air circulation. The thermal analysis of inductor are carried out by means of a Computational Fluid Dynamics (CFD) model and simulations. The paper describes modelling of magnetic core and relatively complex winding bodies with integrated air ducts. The CFD thermal model is experimentally evaluated.

EPE 2017 - DS1c: Passive Components
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2017 ECCE Europe - Conference > EPE 2017 - Topic 01: Devices, Packaging and System Integration > EPE 2017 - DS1c: Passive Components
	[return to parent folder]

	A Comparative Study of Output Filter Efficiency and Power Density in Single-Phase Grid-Tied Inverter Using Continuous or Discontinuous Current Mode Operations By RENE ALEXANDER BARRERA-CARDENAS	[View] [Download]
Abstract: This paper introduces the optimal design of a output filter for a Single-Phase Grid-Tied Inverter considering Continuous and Discontinuous Conduction Modes (CCM and DCM). An optimal design procedure has been proposed, which enables to consider different technologies on the inductor design. Technologies on magnetic materials and wire types has been considered and their benefits for CCM and DCM solutions have been detected. It has been found that Powder magnetic materials allow to improve the Volume-Loss trade-off on output filters when DCM operation is considered for Single-Phase Inverters.

	A High-Frequency Semi Co-Axial Transformer With High Insulation Voltage By Matthijs HEUVELMANS	[View] [Download]
Abstract: A semi co-axial transformer concept is described which can be used to transfer energy across a relativelyhigh potential difference without using potting components. The intended purpose of the design is to pro-vide electrically insulated power for heating up the semiconductor devices in a double-pulse test circuitoperating at several kilovolts. Because of the requirement of handling the large potential difference, alarge leakage inductance is anticipated and the LLC topology is used to solve the issue of excessive volt-age drop. The transformer is implemented using ring cores and a primary winding which is led throughthe center inside a shielding tube which in turn has several millimetres of insulation on the outside. Apartfrom the aspects of insulation, this work deals with the choice of core material, wire thickness and type,determining the transformer properties, including the magnetic and electrical losses. Distinctive featuresin the design are the configuration which approaches some of the properties of a coaxial configurationand the inclusion of a thick metallic shield. Results show that a good prediction of the performance canbe achieved using relatively simple techniques.

	Comparative Analysis of Three-Phase and Single-Phase Inductance Measurements of the Three-Phase Inductor By Radoslaw JEZ	[View] [Download]
Abstract: Three-phase inductors are crucial components for power electronic devices. The most typical measurement process of such inductors bases on three-phase power supply, but it causes many difficulties, especially in industrial or manufacturing tests. The proposed alternative is an implementation of single-phase measurements to three-phase inductors. This approach is discussed in the publication.

	Controlled Magnetic Devices in Power Electronic Applications By Peter ZACHARIAS	[View] [Download]
Abstract: Almost all power electronic converters require magnetic devices and some properties of the converters can be controlled with magnetics. New magnetic materials enable implementation of magnetic control of converters also in high switching frequency applications. The presented paper gives an overview about controllability of magnetic devices in theory and practice, simulation approaches and examples. The focus is on electrically controllable magnetic devices. This means that an additional control winding is wound on or integrated into the magnetic core of the device. This additional winding is used to control the inductive behavior of the device by injecting a current. The different basic control approaches of magnetic devices are explained theoretically and demonstrated experimentally by laboratory prototypes. Several controllable magnetic devices were tested in order to evaluate the applicability of the different control methods. The control techniques were demonstrated also with different core materials to address different applications. Especially ferromagnetic alloys and ferrite materials are in focus of the investigation. Moreover, first approaches for the modelling and simulation of controllable magnetic devices are given in the paper.

	Design method for the minimization of common-mode inductor volume taking into account saturation issues in EMI filters for variable duty cycle applications By Bilel ZAIDI	[View] [Download]
Abstract: The subject of this paper is to propose a design method of the EMI filters that allows to minimize the volume of the common-mode inductor with consideration of core saturation issues. Inductor volume depends not only on its inductance value, but also on the relationship between the filter and its environment which can saturate the magnetic material due to many parameters, especially when the filter resonance frequency Fr is higher than the converter switching frequency Fs. One of these parameters is the converter duty cycle D. This study explains why it is more desirable to set Fr below Fs in order to reduce the coupled inductor volume while increasing the filter performances.

	Development of a magnetic circuit component to predict magnetic waveforms and core losses in a circuit type software By Alexis FOUINEAU	[View] [Download]
Abstract: Medium frequency transformers are an essential part of new energy conversion systems, and are very often subject to non-sinusoidal excitation. Therefore, usual methods to represent magnetic materials behavior inside transformers with electrical equivalent scheme are very limited in this case. This paper focuses on the development of a new model based on the loss separation method. This model is implemented in a circuit simulation software with the VHDL-AMS modeling language to represent the behavior of a flux tube: non-linearity, hysteresis and losses. It allows to obtain relevant results for any excitation waveform as the model is temporal. The developed model was compared with experimental results on a small-scale nanocrystalline transformer prototype and it remains very accurate regarding the hysteresis cycle shape and core losses over a wide frequency range, and also for different waveforms.

	Fundamental Investigation of very fast Transients in Power-Electronic Winding for Solid-State Transformers By Tobias APPEL	[View] [Download]
Abstract: There are problems with insulation failures in high-voltage transformers due to fast transient voltages. Within novel Solid-State Transformers (SST) this problem exists constitutionally because of the SSTs rectangular working voltages. Experiments and simulations have been performed to get accurate understanding of the phenomena. The results and theories are discussed in this paper.

	High power density DC/DC-converter using coupled inductors By Patrick DECK	[View] [Download]
Abstract: This paper presents a high power density coupled tape-wound inductor consisting of nano-crystallinematerial used in a DC/DC converter. In a first step the comparison of the 2-phase coupled inductor(CI) with the 2-phase interleaved converter (SII) is presented. Second step is designing the CI rho/eta-pareto analysis. To test the device a high power density SiC-converter is designed. The experimentallytested prototype is operating at Vh = 400V, i = 100A, fs = 90kHz, aimed at an overall power density ofrho = 40kW/l.

	Hybrid Magnetics and Power Converter Applications By Wai Keung MO	[View] [Download]
Abstract: A hybrid magnetic approach, consisting of merging two different magnetic core properites such as ferrite and ironpowder cores together, is an effective solution for power converter applications. It can provide similar magnetic properties to that of magnetic powder cores but showing less copper loss than powder cores. Additionally, the relatively large inductance at low loading current is an excellent way to minimize total power loss, achieving high efficiency. In order to prevent ferrite core saturation, placing an effective air gap within the ferrite core is a key method to obtain optimum hybrid magnetic performance.

	Hysteresis modelling of a medium frequency single-phase transformer By Piotr DWORAKOWSKI	[View] [Download]
Abstract: The article describes a feedback Preisach hysteresis model equivalent circuit implementation of a medium frequency single-phase transformer being a part of a high power and high efficiency DC-DC converter. The macroscopic models of magnetic hysteresis are introduced and the feedback Preisach model is selected for further analysis. The hysteresis model is developed for a prototype transformer and the hysteresis loops are compared against a measurement. The equivalent circuit implementation of the hysteresis model is proposed and analysed. The equivalent circuit model is validated in no load operation and compared with a measurement.

	Impacts on the Current Distribution of Metal Oxide Varistors for Overvoltage Protection in IGBT Modules By Fabian HOHMANN	[View] [Download]
Abstract: This paper presents impacts of the characteristics of Metal Oxide Varistors (MOV) for selecting and calculating the suited amount of MOVs to enable semiconductors to act as DC-Breakers. The specific structure of zinc oxide shows dependencies in its voltage and current characteristics which exhibits a hysteresis.

	Integrated magnetic element for improving efficiency of LLC resonant converter By Cezary WOREK	[View] [Download]
Abstract: This paper presents a design and construction of an integrated magnetic element IME to achieve high efficiency and high power density in 1250 W LLC resonant converter. The advantage of the presented LLC-type resonant converter structure, with integrated magnetic element (IME) is the possibility of easy adaptation to various power levels. Superposition of two magnetic inductions oriented antiparallelly in the chosen areas of IME allows reduction of the volume required for inductive elements, increased coefficient of transferred power to volume and reduction of parasitic capacitances. In addition, due to a nearly sinusoidal shapes of currents in the resonant circuit, the losses due to operating frequency are also minimal. Thus, the described DC-DC resonant converter dedicated for lighting application based on special integrated magnetic element (IME) has achieved requirements concerning low-cost and high-efficiency. The magnetic component can utilize one or two pairs of the cores. Scalable core construction allows to build a power supply with power range from 300W to 1500W.

	Novel Insulation Concept for an MV Dry-Cast Medium-Frequency Transformer By Thomas GRADINGER	[View] [Download]
Abstract: A 240 kVA, 10 kHz medium-frequency transformer (MFT) to be used in MV DC/DC conversion was developed. The transformer has separately dry-cast windings and was designed for DC system voltages up to 50 kV. For dimensioning and optimization, a MATLAB-based tool was used, containing fast models for electromagnetic, insulation, and thermal design, as well as losses in windings and core. Starting from a small set of primary parameters, a particular MFT design is completed, and an optimization parameter is determined, containing specific MFT cost and size. Automatic optimization is achieved by sweeping over the space of primary parameters, using meshes of increasing resolution. The optimal MFT design was verified and the field grading analyzed in more detail using 3-d electrostatic simulation. Prototypes were built and the insulation was experimentally verified by 70 kV AC and 150 kV lightning impulse tests. Careful field grading and insulation of the HV connections are key to avoid discharges in air up to the PD test voltage, flashovers, and discharges to the nearby grounded components of the MFT. The experimental verification included thermal tests that demonstrated the attractive combination of small air-insulation distances and efficient air cooling of the chosen MFT concept.

	OBSERVATION OF ARCING INSIDE A FUSE UNDER CAPACITOR-DISCHARGE USING 1 MILLION FRAMES PER SECOND X-RAY IMAGING By Jean-Louis GELET	[View] [Download]
Abstract: Despite their apparent banality, fuses are still obligatory components in modern electrical equipment by offering the ultimate protection against faulty conditions and guaranteeing the disconnection of the damaged legs. Melting of the conducting wire is not as intricate as cancellation of the current by the electrical arc occurring during fuse-operation. Generations of engineers and scientists investigated for understanding complex phenomena related to interaction between arc and sand arranged as energy absorbent.Most of their observations have been run post mortem. All had the dream to make the actual movie of an arc inside the fuse-envelop. A few of them approached this fantasy by using diverting ways such as spectroscopy through a window or matrix of magnetic sensors. Unfortunately that gave deficient information. For the first time a team from MERSEN, together with researchers from SIMAP-laboratory at the University of Grenoble took profit of the facilities of the ESRF-synchrotron also in Grenoble to proceed to ultra-fast X-ray imaging of the arc inside the envelop. Observations up to 1,000,000 frames per second have been performed. Analysis of the records brings valuable information about the arc in the fuse and allows adjusting models, with a major interest for very fast operation under high di/dt.

	Optimal inductor winding geometries for minimizing winding loss in gapped inductor designs By Wai Keung MO	[View] [Download]
Abstract: This paper summarizes geometrical effects on inductor winding loss based on fixed and variable wire diametermethods as well as core gap effects. Relevant AC and DC winding resistance equations are derived and an effective inductor design method is given to consider the ratio of alternating to direct current and ratio of skin depth to wire radius r. The core gap effect on the ac winding resistance can be minimized by increasing the distance far away from the gap, however thedc winding resistance will increase. Hence the optimal distance results in the minimum total winding resistance. Finally, a new concept of a two step core gap solution is verified by FEA simulation showing the further winding loss improvement by the smart design method of core gap geometries.

	Thermal Behaviour of DC Power Inductor of 600 kW Power Supply for Particle Accelerators By Danijel MATEJEVIC	[View] [Download]
Abstract: The paper investigates a thermal behaviour of a DC inductor deployed in a 600 kW power converter for particle accelerators. The inductor is manufactured from electrical steel core and two magnetically coupled windings with integrated air ducts for enhanced air circulation. The thermal analysis of inductor are carried out by means of a Computational Fluid Dynamics (CFD) model and simulations. The paper describes modelling of magnetic core and relatively complex winding bodies with integrated air ducts. The CFD thermal model is experimentally evaluated.