EPE Association: EPE 2014 - DS3a: Passive Components

EPE 2014 - DS3a: Passive Components
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2014 ECCE Europe - Conference > EPE 2014 - Topic 01: Devices, Packaging and System Integration > EPE 2014 - DS3a: Passive Components

   [return to parent folder]

   Analytical Determination of the First Resonant Frequency of Differential Mode Chokes by Detailed Analysis of Parasitic Capacitances
By Lars MIDDELSTAEDT, Stanislav SKIBIN, Reinhard DOEBBELIN, Andreas LINDEMANN [View]
[Download]

Abstract: In this paper the important parasitic capacitances of chokes are analyzed and defined. This work contributesto a general understanding of capacitive coupling in wound elements. Based on calculations from previous studies a more precise, wide range algorithm is proposed to calculate these parasitic capacitances of toroidal chokes. With these results a method is presented to analytically predict the first resonant frequency of a differential mode choke with high precision. Furthermore, the retrieved capacitance network offers the possibility to forecast resonant frequencies of higher order with high accuracy avoiding the need of measurement or field simulation.

   Carbon Nanotube Supercellulose Supercapacitor
By Henri AALTO, Juha PYRHÖNEN, Lasse LAURILA, Kaj BACKFOLK, Tuomas KOIRANEN, Kirill MURASHKO, Katja LYYTIKÄINEN [View]
[Download]

Abstract: Supercellulose gel and single-wall carbon nanotubes (SWCNTs) were used for the creation of binder-freeelectrode for supercapacitor application and the properties of the electrode were investigated in aqueouselectrolyte. Two layers of the formed composite material were inserted on graphite current collectors andseparated from each other by a separator to create a supercapacitor prototype for measurements. Different concentrations of SWCNTs were studied and 65\% concentration of SWCNTs resulted in the highestspecific capacitance.

   Core and air gap influence on the accuracy of inductor AC winding resistance calculation methods
By Vesa VÄISÄNEN, Jani HILTUNEN, Pertti SILVENTOINEN [View]
[Download]

Abstract: This paper discusses the accuracy of typical AC resistance calculation methods in gapped inductors. It is shown that despite the additional losses caused by fringing flux induced eddy currents, the calculated resistances can be overestimated considerably due to non-tangential field distribution and reduced winding proximity losses. However, this phenomenon is not so significant with windings having only a few winding layers; in such cases 1D calculation methods can be useful in predicting the winding resistances. It is also demonstrated how the fringing flux induced losses affect the calculated results and how they can be taken into account when using the 1D methods.

   Current Sharing Design Assessment of DC Link Capacitor Module
By Nan CHEN, Muhammad NAWAZ [View]
[Download]

Abstract: In power converter design, especially in high power applications, considerable effort have been made on developing DC link capacitor with low stray inductance for the purpose of loss reduction. However, considering practical design requirement, lower stray inductance is not necessarily beneficial for the system. Study on current balancing across capacitor units is performed in this paper. Analysis shows that higher busbar stray inductance can help to improve capacitor internal current balancing during switching transient. An optimization between current balancing in capacitor units and voltage overshoot on semiconductor device should be taken into consideration for converter design. A single pulse test (SPT) setup in half-bridge configuration using 4.5 kV Si-IGBT StakPak power modules is built to verify the theoretical analysis.

   Design, Analysis and Simulation of Magnetic Biased Inductors with Saturation-Gap.
By Andres REVILLA AGUILAR, Stig MUNK-NIELSEN [View]
[Download]

Abstract: AbstractPermanent magnet biasing, is a known technique for increasing the energy storage capability of inductors operating in DC applications. The opposing flux introduced by a permanent magnet will extend the saturation flux limit of a given magnetic material. When full biasing of the core is achieved, the effective saturation current limit of a given inductor is doubled. This results in a smaller requirement in number of turns and area cross-section, allowing for smaller and/or more efficient inductors. By adding some switching elements, the benefits of biased inductors can also be used in AC applications. This paper presents a review of the scientific literature on biased hybrid inductors and the evolution of the used magnets and cores configurations. A recently developed biasing configuration, the saturation-gap, will also be analyzed and the design parameter will be identified using finite element software. The simulation results will be compared with empirical laboratory measurements on physical units.

   Input filter damping without external passive components
By Jani HILTUNEN, Vesa VÄISÄNEN, Pertti SILVENTOINEN [View]
[Download]

Abstract: In this paper, a method to damp an input filter without external passive components is presented. Presented method provides a simple and cost-effective filtering for high switching frequency applications. In this paper, a design procedure is presented and an example design case is provided with measurement results.

   Investigation of Acoustic Noise Sources in Medium Frequency, Medium Voltage Transformers
By Peng SHUAI, Jürgen BIELA [View]
[Download]

Abstract: Medium voltage, medium frequency transformers (MFTs) are much smaller in size and weight compared to conventional low frequency transformers. The MFTs are very attractive for applications where full control of the power flow and high power density are required, such as power electronic interfaces in smart grids and traction converter systems. Due to the limitation of high voltage semiconductor switches, the MFTs are usually operated in the kHz range, which results in acoustic noise radiated from the transformer. In this paper, the origins of acoustic noise associated with MFTs are investigated based on vibration and acoustic measurements. The investigation focuses on the core materials widely used for MFTs, i.e. the amorphous and the nanocrystalline alloy. Experimental results show that the nanocrystalline core features lower level of vibration and acoustic noise emission than the amorphous core. Comparing core shapes, the toroidal core has better vibration and acoustic performance than the U-shape core. The existence of air gap in case of a cut core leads to excessive vibrations and therefore higher acoustic noise level due to increased magnetic forces compared with uncut core. Based on analysis of measurement results, recommendations for low noise MFT design are proposed.

   Low Loss Magnetic Inductor for High Efficiency DC-DC Converter
By Santosh KULKARNI, Paul MCCLOSKEY, Ningning WANG, Zoran PAVLOVIC, Li DAI, George YOUNG, Cian O'MATHUNA [View]
[Download]

Abstract: Advances in wide bandgap semiconductor technologies have enabled increased switching frequencies,which is critical for reducing size of passive components in power supplies. These advances in powerconversion technologies have highlighted the need for development of new class of magneticscomponents (inductors, transformers etc) with lower footprint and higher efficiency. Presently, thesizes of these magnetic components have been limited due to the use of low flux density ferrite as acore material. In this paper, we present the assembly and working of a nanocrystalline thin filminductor with low loss performance as a replacement for ferrite based inductors. The performance ofthe thin film inductor is characterized in a commercial 500 kHz evaluation board. The paper alsoshows the significant reduction in footprint with the thin film inductor using an oxide as insulationbetween magnetic layers.

EPE 2014 - DS3a: Passive Components
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2014 ECCE Europe - Conference > EPE 2014 - Topic 01: Devices, Packaging and System Integration > EPE 2014 - DS3a: Passive Components
	[return to parent folder]

	Analytical Determination of the First Resonant Frequency of Differential Mode Chokes by Detailed Analysis of Parasitic Capacitances By Lars MIDDELSTAEDT, Stanislav SKIBIN, Reinhard DOEBBELIN, Andreas LINDEMANN	[View] [Download]
Abstract: In this paper the important parasitic capacitances of chokes are analyzed and defined. This work contributesto a general understanding of capacitive coupling in wound elements. Based on calculations from previous studies a more precise, wide range algorithm is proposed to calculate these parasitic capacitances of toroidal chokes. With these results a method is presented to analytically predict the first resonant frequency of a differential mode choke with high precision. Furthermore, the retrieved capacitance network offers the possibility to forecast resonant frequencies of higher order with high accuracy avoiding the need of measurement or field simulation.

	Carbon Nanotube Supercellulose Supercapacitor By Henri AALTO, Juha PYRHÖNEN, Lasse LAURILA, Kaj BACKFOLK, Tuomas KOIRANEN, Kirill MURASHKO, Katja LYYTIKÄINEN	[View] [Download]
Abstract: Supercellulose gel and single-wall carbon nanotubes (SWCNTs) were used for the creation of binder-freeelectrode for supercapacitor application and the properties of the electrode were investigated in aqueouselectrolyte. Two layers of the formed composite material were inserted on graphite current collectors andseparated from each other by a separator to create a supercapacitor prototype for measurements. Different concentrations of SWCNTs were studied and 65\% concentration of SWCNTs resulted in the highestspecific capacitance.

	Core and air gap influence on the accuracy of inductor AC winding resistance calculation methods By Vesa VÄISÄNEN, Jani HILTUNEN, Pertti SILVENTOINEN	[View] [Download]
Abstract: This paper discusses the accuracy of typical AC resistance calculation methods in gapped inductors. It is shown that despite the additional losses caused by fringing flux induced eddy currents, the calculated resistances can be overestimated considerably due to non-tangential field distribution and reduced winding proximity losses. However, this phenomenon is not so significant with windings having only a few winding layers; in such cases 1D calculation methods can be useful in predicting the winding resistances. It is also demonstrated how the fringing flux induced losses affect the calculated results and how they can be taken into account when using the 1D methods.

	Current Sharing Design Assessment of DC Link Capacitor Module By Nan CHEN, Muhammad NAWAZ	[View] [Download]
Abstract: In power converter design, especially in high power applications, considerable effort have been made on developing DC link capacitor with low stray inductance for the purpose of loss reduction. However, considering practical design requirement, lower stray inductance is not necessarily beneficial for the system. Study on current balancing across capacitor units is performed in this paper. Analysis shows that higher busbar stray inductance can help to improve capacitor internal current balancing during switching transient. An optimization between current balancing in capacitor units and voltage overshoot on semiconductor device should be taken into consideration for converter design. A single pulse test (SPT) setup in half-bridge configuration using 4.5 kV Si-IGBT StakPak power modules is built to verify the theoretical analysis.

	Design, Analysis and Simulation of Magnetic Biased Inductors with Saturation-Gap. By Andres REVILLA AGUILAR, Stig MUNK-NIELSEN	[View] [Download]
Abstract: AbstractPermanent magnet biasing, is a known technique for increasing the energy storage capability of inductors operating in DC applications. The opposing flux introduced by a permanent magnet will extend the saturation flux limit of a given magnetic material. When full biasing of the core is achieved, the effective saturation current limit of a given inductor is doubled. This results in a smaller requirement in number of turns and area cross-section, allowing for smaller and/or more efficient inductors. By adding some switching elements, the benefits of biased inductors can also be used in AC applications. This paper presents a review of the scientific literature on biased hybrid inductors and the evolution of the used magnets and cores configurations. A recently developed biasing configuration, the saturation-gap, will also be analyzed and the design parameter will be identified using finite element software. The simulation results will be compared with empirical laboratory measurements on physical units.

	Input filter damping without external passive components By Jani HILTUNEN, Vesa VÄISÄNEN, Pertti SILVENTOINEN	[View] [Download]
Abstract: In this paper, a method to damp an input filter without external passive components is presented. Presented method provides a simple and cost-effective filtering for high switching frequency applications. In this paper, a design procedure is presented and an example design case is provided with measurement results.

	Investigation of Acoustic Noise Sources in Medium Frequency, Medium Voltage Transformers By Peng SHUAI, Jürgen BIELA	[View] [Download]
Abstract: Medium voltage, medium frequency transformers (MFTs) are much smaller in size and weight compared to conventional low frequency transformers. The MFTs are very attractive for applications where full control of the power flow and high power density are required, such as power electronic interfaces in smart grids and traction converter systems. Due to the limitation of high voltage semiconductor switches, the MFTs are usually operated in the kHz range, which results in acoustic noise radiated from the transformer. In this paper, the origins of acoustic noise associated with MFTs are investigated based on vibration and acoustic measurements. The investigation focuses on the core materials widely used for MFTs, i.e. the amorphous and the nanocrystalline alloy. Experimental results show that the nanocrystalline core features lower level of vibration and acoustic noise emission than the amorphous core. Comparing core shapes, the toroidal core has better vibration and acoustic performance than the U-shape core. The existence of air gap in case of a cut core leads to excessive vibrations and therefore higher acoustic noise level due to increased magnetic forces compared with uncut core. Based on analysis of measurement results, recommendations for low noise MFT design are proposed.

	Low Loss Magnetic Inductor for High Efficiency DC-DC Converter By Santosh KULKARNI, Paul MCCLOSKEY, Ningning WANG, Zoran PAVLOVIC, Li DAI, George YOUNG, Cian O'MATHUNA	[View] [Download]
Abstract: Advances in wide bandgap semiconductor technologies have enabled increased switching frequencies,which is critical for reducing size of passive components in power supplies. These advances in powerconversion technologies have highlighted the need for development of new class of magneticscomponents (inductors, transformers etc) with lower footprint and higher efficiency. Presently, thesizes of these magnetic components have been limited due to the use of low flux density ferrite as acore material. In this paper, we present the assembly and working of a nanocrystalline thin filminductor with low loss performance as a replacement for ferrite based inductors. The performance ofthe thin film inductor is characterized in a commercial 500 kHz evaluation board. The paper alsoshows the significant reduction in footprint with the thin film inductor using an oxide as insulationbetween magnetic layers.