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.
In modern power electronic systems, voltages across inductors or transformers generally show rectangular shapes, including periods of zero voltage. In the stage of zero applied voltage (constant ...flux), core losses are not necessarily zero. At the beginning of a period of constant flux, losses still occur in the material. This is due to relaxation processes. A physical explanation about magnetic relaxation is given and a new core-loss modeling approach that takes relaxation effects into consideration is introduced. The new loss model is called improved-improved generalized Steinmetz equation and it has been verified experimentally.
Inductive components such as line filter inductors or transformers occupy a significant amount of space in today's power electronic systems, and furthermore, considerable losses occur in these ...components. A main application of inductive components is EMI filters, as, e.g., employed for the attenuation of switching frequency harmonics of power factor correction (PFC) rectifier systems. In this paper, a design procedure for the mains side LCL filter of an active three-phase rectifier is introduced. The procedure is based on a generic optimization approach, which guarantees a low volume and/or low losses. Different designs are calculated to show the tradeoff between filter volume and filter losses. The design procedure is verified by experimental measurements. Furthermore, an overall system optimization, i.e., an optimization of the complete three-phase PFC rectifier, is given.
This paper describes a bidirectional switch commutation strategy for a three-phase to two-phase matrix converter supplying a series resonant load. Classical modulation techniques are not applicable ...because of the needed high output frequencies. This fact, together with the different topology compared to classical three-phase to three-phase matrix converters, makes a new investigation of commutation principles necessary. The paper shows that the three-phase to two-phase resonant matrix converter can be compared with the full-bridge series-resonant converter. Thus, the commutation of the full-bridge series-resonant converter gives the conditions for the bidirectional switch commutation at the matrix converter. One of the main benefits of the derived strategy is the minimization of commutation steps independent of the load current sign.
In modern power electronic systems, voltages across inductors/transformers generally show rectangular shapes, as the voltage across an inductor/transformer can be positive, negative or zero. In the ...stage of zero applied voltage (constant flux) core losses are not necessarily zero. At the beginning of a period of constant flux, losses still occur in the material. This is due to relaxation processes. A physical explanation about magnetic relaxation is given and a new core loss modeling approach that takes such relaxation effects into consideration is introduced. The new loss model is called i 2 GSE and has been verified experimentally.
When designing inductive components, calculating core losses is a difficult and not yet entirely solved problem. In particular it is impossible to predict the influence of a DC premagnetization on ...the losses without performing extensive measurements. For this work, different materials have been tested to gain information how core losses are influenced by a premagnetization. Measurements on molypermalloy powder, silicon steel, nanocrystalline material, and ferrite cores have been performed. Of the tested materials, a premagnetization mainly influences losses in ferrites and nanocrystalline materials, whereas the influence of a premagnetization in molypermalloy powder cores, and cores of silicon steel is negligible. The Steinmetz Premag-netization Graph (SPG) that shows the dependency of the Steinmetz parameters (α, β and k) 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.
This paper describes the analysis and development of a new contactless energy transmission system (GETS) for applications with flexible inductor positioning. Therefore it compares the full bridge ...series-series-resonant and series-parallel-resonant converter for their usability in applications with large air gaps and a flexible positioning of the windings as, for example, given for inductive battery charging of automated guided vehicles. With the selection of the right converter topology, an independent design of the transmission system for a varying air gap or misalignments is possible. Finally measurements of a built resonant converter that transfers 1 kW proof the significant benefits of the series-series-resonant converter for this special application
Inductive components such as line filter inductors or transformers occupy a significant amount of space in today's power electronic systems, and furthermore, considerable losses occur in these ...components. A main application of filter inductors are EMI filters, as e.g. employed for the attenuation of switching frequency harmonics of PFC rectifier systems. In this paper a design procedure for the mains side LCL filter of an active three-phase rectifier is introduced. The procedure is based on a generic optimization approach, which guarantees a low volume and/or low losses. Different designs are calculated to show the trade-off between filter volume and filter losses. The design procedure is verified by experimental measurements.
An EMI filter design procedure for power converters is proposed. Based on a given noise spectrum, information about the converter noise source impedance and design constraints, the design space of ...the input filter is defined. The design is based on component databases and detailed models of the filter components, including high frequency parasitics, losses, weight, volume, etc.. The design space is mapped onto a performance space in which different filter implementations are evaluated and compared. A multi-objective optimization approach is used to obtain optimal designs w.r.t. a given performance function.
Loss models of inductive components are thoroughly investigated, thereby all different aspects of loss modeling are considered. The impact of peak-to-peak flux density ΔB, frequency f, DC ...premagnetization H DC , temperature T, core shape, minor and major loops, flux waveform, and material on core loss calculation are considered. In order to calculate winding losses, formulas for round conductors and litz wires, each including skin- and proximity effects (including the influence of an air-gap fringing field) are included. A high level of accuracy is achieved by combining the best state-of-the-art approaches and by embedding newly-developed approaches into a novel loss calculation framework. The loss models are verified by FEM simulations and experimental measurements.
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