Showing papers on "Magnetic core published in 2011"

Improved Core-Loss Calculation for Magnetic Components Employed in Power Electronic Systems

Abstract: 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 i2GSE and has been verified experimentally.

Cryogenic magnetocaloric effect in a ferromagnetic molecular dimer.

Abstract: Over the last few years, great interest has emerged in the synthesis and magnetothermal studies of molecular clusters based on paramagnetic ions, often referred to as molecular nanomagnets, in view of their potential application as lowtemperature magnetic refrigerants. What makes them promising is that their cryogenic magnetocaloric effect (MCE) can be considerably larger than that of any other magnetic refrigerant, for example, lanthanide alloys and magnetic nanoparticles. The MCE is the change of magnetic entropy (DSm) and related adiabatic temperature (DTad) in response to the change of applied magnetic field, and it can be exploited for cooling applications via a field-removal process called adiabatic demagnetization. Although the MCE is intrinsic to any magnetic material, in only a few cases are the changes sufficiently large to make them suitable for applications. The ideal molecular refrigerant comprises the following key characteristics: 1) a large spin ground state S, since the magnetic entropy amounts to R ln(2S+1); 2) a negligible magnetic anisotropy, which permits easy polarization of the net molecular spins in magnetic fields of weak or moderate strength; 3) the presence of low-lying excited spin states, which enhances the field dependence of the MCE owing to the increased number of populated spin states; 4) dominant ferromagnetic exchange, favoring a large S and hence a large field dependence of the MCE; 5) a relatively low molecular mass (or a large metal/ligand mass ratio), since the nonmagnetic ligands contribute passively to the MCE. Although this last point is crucial for obtaining an enhanced effect, it has beenmostly ignored to date. Molecular cluster compounds tend to have a very low magnetic density because of the large complex structural frameworks required to encase the multinuclear magnetic core. Herein we propose a drastically different approach by focusing on the simple and well-known ferromagnetic molecular dimer gadolinium acetate tetrahydrate, [{Gd(OAc)3(H2O)2}2]·4H2O (1). [4a,b] The structure of 1 (Figure 1) com-

Interleaved Critical Current Mode Boost PFC Converter With Coupled Inductor

Abstract: Interleaved critical current mode (CRM) boost power factor correction (PFC) converter is widely employed recently for its high power density. In order to further reduce the volume and the copper usage of the magnetic components, two-phase interleaved CRM boost PFC converter with a coupled inductor is analyzed in this paper. The coupling effects on the input current, the inductor current, the switching frequency and the flux linkage are analyzed separately. If the self-inductances and the magnetic core are the same for both coupled and noncoupled inductors, the number of winding turns of coupled inductor is fewer than that of the noncoupled inductor, which implies a lower cost. Although the input current ripple increases a little since coupling, a reduction in the total volume of magnetic components, including the electromagnetic interference filter and the coupled inductor, is possible if the coupling coefficient is made reasonable.

Low core losses and magnetic properties of Fe85-86Si1-2B8P4Cu1 nanocrystalline alloys with high B for power applications (invited)

Abstract: Recently, the energy crisis and the continued growth in electrical power generation strongly demand minimization of wasteful energy dissipation. Magnetic core loss (W) is the main source of energy dissipation in motors and transformers. This requires the development of soft magnetic materials with low coercivity (Hc) and high magnetic flux density (B). Fe-rich Fe85-86Si1-2B8P4Cu1 (at. %) alloy ribbons made from industrial raw materials (containing some impurities) with 6 mm in width have a heteroamorphous structure containing a large number of extremely small Fe grains (less than 3 nm), resulting from the unique effects of P and Cu addition in proper amounts. Crystallization of these alloys by annealing shows a uniform precipitation of α-Fe, leading to a uniform nanocrystallized structure of α-Fe grains, 16–19 nm in size, accompanied by an intergranular amorphous layer about 1 nm in width. The wide ribbons exhibit high B of 1.82–1.85 T (at 800 A/m), almost comparable to commercial oriented Fe–3 mass% Si a...

Finite-Element Analysis of Short-Circuit Electromagnetic Force in Power Transformer

Abstract: Transient electromagnetic forces in radial and axial directions induce critical mechanical stress on windings and transformers. In this paper, short-circuit electromagnetic forces that are exerted on transformer windings are investigated. A 3-D transformer model is considered to calculate the transient electromagnetic forces. The magnetic vector potential, magnetic flux density, and electromagnetic forces due to the short-circuit transient currents applied to the power transformer are analyzed by a coupled electromechanical finite-element method. The results obtained are compared with the analytical results and show good agreement. The numerical modeling technique dealt with in this paper is expected to be useful in the design of power transformers.

The Three-Phase Common-Mode Inductor: Modeling and Design Issues

Abstract: This paper presents a comprehensive physical characterization and modeling of the three-phase common-mode (CM) inductors along with the equivalent circuits that are relevant for their design. Modeling issues that are treated sparsely in previous literature are explained in this paper, and novel insightful aspects are presented. The calculation of the leakage inductance is reviewed, along with the magnetic core saturation issues, and a new expression for the leakage flux path is derived. The influence of the core material characteristics on the performance of the component is discussed, and a new method for the selection of the material for the minimized volume CM inductors is proposed in order to simplify the design procedure. Experimental results which validate the model are presented.

Design Principles of a Symmetrically Coupled Inductor Structure for Multiphase Synchronous Buck Converters

Abstract: The multiphase interleaved synchronous buck converters with coupled phase inductors are being preferred for voltage regulator modules requiring low output voltage, high output current, and fast transient response since they simultaneously offer better steady-state efficiency and faster dynamic response. In this paper, a novel magnetic core structure for symmetrical coupling of multiphase buck converter phase inductors is proposed, which overcomes several limitations of asymmetrical inductor coupling proposed so far. A new analytical technique to arrive at simple dynamic equivalent circuits of the converter, as well as design guidelines for the proposed inductor structure, is presented. Experimental results from a prototype four-phase synchronous buck converter with the proposed inductor demonstrate 2% to 6% improvement in the converter efficiency compared to a similarly rated converter with uncoupled inductors while retaining the same transient performance.

A high frequency core loss measurement method for arbitrary excitations

Abstract: Recently, point of load (POL) converter are pushed to higher switching frequency for higher power density. As the frequency increases, magnetic core loss becomes a significant part of the total loss of POL converters. Accurate measurement of this part of loss is important for the converter design. And the core loss under non-sinusoidal excitation is particularly interesting for pulse-width modulation (PWM) converters. However, precise measurement is difficult with classical four-wire methods, because of high frequency and non-sinusoidal flux waveform (like triangular flux). In this paper, a new method is proposed for high frequency core loss measurement with arbitrary excitation. The principle is to cancel the reactive power in the core under test with a lossless or low-loss core and reduce the sensitivity to phase discrepancy. By doing this, phase discrepancy induced error can be significantly reduced, and accurate measurement can be achieved for higher frequency than conventional method.

Isolated Winding-Coupled Bidirectional ZVS Converter With PWM Plus Phase-Shift (PPS) Control Strategy

Abstract: A novel winding-coupled bidirectional dc/dc converter with zero-voltage-switching (ZVS) performance is proposed in this paper. In the low-voltage side, the parallel configuration is employed to share the large current and reduce the current ripple. In the high-voltage side, the series structure is adopted to sustain the high bus voltage and achieve large voltage ratio conversion. There are only two coupled inductors in the proposed interleaved bidirectional converter and their secondary windings are in series to serve as winding-coupled inductors. Furthermore, the two winding-coupled inductors can be integrated into a magnetic core to reduce the passive component numbers and improve the power density. Moreover, ZVS soft-switching operation is implemented for all the power switches to minimize the switching losses by introducing the active clamp scheme. In addition, the pulsewidth modulation plus phase-shift control strategy is employed to reduce the power MOSFET peak current and diminish the circulating losses. The duty cycle is applied to balance the voltages of both sides. The phase-shift angle is introduced to realize the power flow regulation. This decoupling control strategy is advantageous for bidirectional dc/dc conversion to realize high efficiency. Finally, a 1-kW prototype is built to verify the effectiveness of the proposed circuit.

Energy Harvesting of Magnetic Power-Line Noise

Abstract: The purpose of this study is to demonstrate the energy harvesting of power-line magnetic noise. To the best of the authors' knowledge, no research has yet been carried out to confirm this possibility. In this paper, we present a simple circuit design model, and confirm its validity by experimental results. For small self-sufficient devices in a wireless sensor network, the target energy level is 1 mW. We prepare an energy harvesting module with an air-core coil and resonant capacitor. From experimental and simulated results, we investigate the desired conditions for harvesting 1 mW from a uniform magnetic field of 60 Hz. Through experimental results with iron cores, the benefits and drawbacks of the use of a magnetic core are also discussed. With our best harvested module, we successfully demonstrated the energy harvesting of 6.32 mW from a magnetic field of 21.2 μT at 60 Hz. If the usable magnetic flux density increases tenfold, the harvesting energy increased 100-fold. If the magnetic flux density is at an acceptable level in a public space of 200 μT at 60 Hz, the harvesting power density becomes 130 μW/cm3. This value is comparable to the value of an energy harvesting module of a light source during a cloudy day.

Small size and fully integrated power converter with magnetics on chip

Abstract: An integrated circuit has a semiconductor die provided in a first IC layer and an inductor fabricated on a second IC layer. The inductor may have a winding and a magnetic core, which are oriented to conduct magnetic flux in a direction parallel to a surface of a semiconductor die. The semiconductor die may have active circuit components fabricated in a first layer of the die, provided under the inductor layer. The integrated circuit may include a flux conductor provided on a side of the die opposite the first layer. PCB connections to active elements on the semiconductor die may progress through the inductor layer as necessary.

Magnetic-Core and Air-Core Inductors on Silicon: A Performance Comparison up to 100 MHz

Abstract: What is the future of integrated inductor design on silicon for power conversion applications at frequencies up to 100 MHz-is it magnetic-core or air-core inductors. This study presents measured results for two microfabricated inductors (magnetic core and air core), which have been designed to operate at 20 MHz and occupy a substrate area of less than 10 mm2. The inductor technology and design are briefly discussed. An optimized inductor design study is, then, presented. Both magnetic-core and air-core inductor designs are compared and evaluated, in terms of inductance and efficiency per unit area for frequencies up to 100 MHz. The design of the microinductors is discussed and an analytical design optimization program is used to model the devices for the maximum efficiency and inductance. The introduction of laminations with high-frequency core inductors will also be examined within the study. A 100 MHz magnetic-core inductor design with three laminations gives a 36 nH inductance, with 96.4% efficiency and an area of 3 mm2 . A comparable air-core design also gives a 36 nH inductance, with 93.45% efficiency and an area of just 2.6 mm2.

Magnetic field effects in artificial dielectrics with arrays of magnetic wires at microwaves

Abstract: A magnetic field tunable electromagnetic response in periodic lattices of conducting magnetic wires is demonstrated. The wire medium having a negative permittivity in the lower frequency band is customarily investigated as an important component of so-called double negative metamaterials. Here we are interested in a strong dispersion of the permittivity in these structures and a possibility to alter it by changing the losses in magnetic wires with an external magnetic field. The theoretical approach is based on calculating the relaxation parameter depending on the wire surface impedance, and hence, on the wire magnetic properties. Thus, in arrays of Co-based amorphous wires the application of a moderate magnetic field (of about 1–2 kA/m) which causes the magnetization reorientation is capable of few fold permittivity change in the frequency range of 1–2 GHz. Such efficient tuning for certain structural and magnetic parameters was confirmed experimentally by measuring the transmission and reflection spectra from lattices of Co66Fe3.5B16Si11Cr3.5 glass-coated amorphous wires with a different wire cross-section and a different lattice period. The chosen wires are also confirmed to show a large magnetoimpedance effect at GHz frequencies, which constitutes the underlying mechanism of magnetic field dependent permittivity in wire media.

Performance Enhancement of On-Chip Inductors With Permalloy Magnetic Rings

Abstract: We demonstrate spiral inductors with continuous Permalloy ring structure at 100-μm scale, which achieve enhancements of sixfold in inductance and threefold in quality factor at frequencies as high as 200 MHz. The roll-off frequency is due to the eddy current loss in the conductive magnetic material. To reduce such loss and tune the permeability, the Permalloy film is laminated and split into bars. The dependence of the inductance and quality factor on permeability is further investigated. Different types of spiral inductors were fabricated with magnetic rings, helping shed light on optimization strategy.

Stability and magnetorheological behaviour of magnetic fluids based on ionic liquids

Abstract: This paper reports the preparation of magnetic fluids consisting of magnetite nanoparticles dispersed in an ionic liquid. Different additives were used in order to stabilize the fluids. Colloidal stability was checked by magnetic sedimentation, centrifugation and direct observation. The results of these tests showed that a true ferrofluid was only obtained when the nanoparticles were coated with a layer of surfactant compatible with the ionic liquid. These experiments also showed that stability could not be reached just by electrostatic repulsion. The conclusions of the stability tests were confirmed by calculations of the interparticle energies of interaction. The rheological behaviour of the magnetic fluids upon magnetic field application was also investigated. The experimental magnetoviscous response was fitted by a microstructural model. The model considered that the fluids consisted of two populations of particles, one with a magnetic core diameter of 9 nm, and another with a larger diameter. Upon field application chain-like structures are supposed to be induced. According to estimations particles of 9 nm are too small to aggregate upon field application. The results of the calculations showed that the intensity of the magnetoviscous response depends on the concentration and size of the large particles, and on the thickness of the surfactant layers.

Torque Density Improvement of Five-Phase PMSM Drive for Electric Vehicles Applications

Abstract: In order to enhance torque density of five-phase permanent magnetic synchronous motor with third harmonic injection for electric vehicles (EVs) applications, optimum seeking method for injection ratio of third harmonic was proposed adopting theoretical derivation and finite element analysis method, under the constraint of same amplitude for current and air-gap flux. By five-dimension space vector decomposition, the mathematic model in two orthogonal space plane, d₁ ?q₁ and d₃ ?q₃, was deduced. And the corresponding dual-plane vector control method was accomplished to independently control fundamental and third harmonic currents in each vector plane. A five-phase PMSM prototype with quasi-trapezoidal flux pattern and its fivephase voltage source inverter were designed. Also, the dual-plane vector control was digitized in a single XC3S1200E FPGA. Simulation and experimental results prove that using the proposed optimum seeking method, the torque density of five-phase PMSM is enhanced by 20%, without any increase of power converter capacity, machine size and iron core saturation.

Electronic Combined Transformer for Power-Quality Measurements in High-Voltage Systems

Abstract: The evolution of electronic technology and digital signal processing is making competitive methods and devices for the design and the development of measurement transformers for high-voltage (HV) systems deeply different from those based on the traditional electromagnetic principle. Several advantages are offered by these new solutions: higher metrological characteristics, cost effectiveness, compact size, and lack of the typical problems of the traditional electromagnetic transformers (magnetic core saturation, magnetic resonance, bandwidth limits, etc.). In this paper, the design criteria adopted for the development of a prototype of a novel HV electronic combined transformer are presented. Its architecture permits the implementation of both voltage and current protective and measurement functions. The starting point is the employment of a mix of well-tested traditional technologies (like those used for the voltage capacitive divider and for the current sensor) and very sophisticated electronics. In particular, the electronic devices and the employed system architecture, beyond what is conceived for obtaining high measurement performances, are also oriented to provide advanced ancillary functions such as autodiagnosis, fault tolerance, autocalibration, etc. The developed combined measurement transformer features a rated primary voltage of 145/√3 kV and a rated primary current of 1000 A. Moreover, it is fully compliant with IEC 60044-7 and IEC 60044-8 standards, assuring 0.1 measurement precision class and satisfying also 5P and 3P protection classes for current and voltage sections, respectively.

Powder Core Material Coupled Inductors And Associated Methods

Abstract: A multi-phase coupled inductor includes a powder core material magnetic core and first, second, third, and fourth terminals. The coupled inductor further includes a first winding at least partially embedded in the core and a second winding at least partially embedded in the core. The first winding is electrically coupled between the first and second terminals, and the second winding electrically is coupled between the third and fourth terminals. The second winding is at least partially physically separated from the first winding within the magnetic core. The multi-phase coupled inductor is, for example, used in a power supply.

Multi-turn inductors

Abstract: A multi-winding inductor includes a first foil winding and a second foil winding. One end of the first foil winding extends from a first side of the core and wraps under the core to form a solder tab under the core. One end of the second foil winding extends from a second side of the core and wraps under the core to form another solder tab under the core. Respective portions of each solder tab are laterally adjacent under the magnetic core. A coupled inductor includes a magnetic core including a first and a second end magnetic element and a plurality of connecting magnetic elements disposed between and connecting the first and second end magnetic elements. A respective first and second single turn foil winding is wound at least partially around each connecting magnetic element. Each foil winding has two ends forming respective solder tabs.

Power control method based CT electricity getting device of high voltage transmission line

Abstract: The invention provides a power control method based CT electricity getting device of a high voltage transmission line, belonging to the field of high voltage technology. The high voltage transmission line successively penetrates through the middles of an electricity getting magnetic core and a measuring magnetic core; an electricity getting magnetic core coil and a measuring magnetic core coil are respectively positioned outside the electricity getting magnetic core and the measuring magnetic core; the electricity getting magnetic core coil is connected with an overvoltage protection and switching relay; the overvoltage protection and switching relay, a rectification filter circuit, a DC/DC module, a power management module and a voltage-stabilizing output circuit are connected; the rectification filter circuit is connected with a voltage-current detection circuit which is connected with the power management module; the power management module is connected with a farad capacitor whichis connected with the voltage-stabilizing output circuit; and the measuring magnetic core coil is connected with a sampling circuit which is connected with the power management module. The invention realizes that stable power is output within a larger current range and prevents the unsaturated situation of the magnetic cores when the current of the transmission line is large without heat-generating problems.

Magnetic core shell nanoparticles trapping in a microdevice generating high magnetic gradient

Abstract: Magnetic core shell nanoparticles (MCSNPs) 30 nm diameter with a magnetic weight of 10% are usually much too small to be trapped in microfluidic systems using classical external magnets. Here, a simple microchip for efficient MCSNPs trapping and release is presented. It comprises a bed of micrometric iron beads (6–8 μm diameter) packed in a microchannel against a physical restriction and presenting a low dead volume of 0.8 nL. These beads of high magnetic permeability are used to focus magnetic field lines from an external permanent magnet and generate local high magnetic gradients. The nanoparticles magnetic trap has been characterised both by numerical simulations and fluorescent MCSNPs imaging. Numerical simulations have been performed to map both the magnetic flux density and the magnetic force, and showed that MCSNPs are preferentially trapped at the iron bead magnetic poles where the magnetic force is increased by 3 orders of magnitude. The trapping efficiency was experimentally determined using fluorescent MCSNPs for different flow rates, different iron beads and permanent magnet positions. At a flow rate of 100 μL h−1, the nanoparticles trapping/release can be achieved within 20 s with a preconcentration factor of 4000.

Permanent magnetic rotating electric machine and wind power generating system

Abstract: A permanent magnet rotating electric machine which can be efficiently reduced a temperature rise in the rotating machine without enlarging a heat exchanger and water-cooling unit. The permanent magnet rotating electric machine comprising a stator with a stator coil wound on a stator iron core, a rotor with a plurality of permanent magnets disposed in the circumferential direction in a rotor iron core, which is disposed opposite to the stator iron core of the stator with a predetermined spacing therebetween and is fixed to a shaft, a water-cooling unit disposed around the outer circumference of the stator iron core, and a fan fixed to the shaft on the same side as at least one axial end of the rotor iron core to circulate cooling air in the permanent magnet rotating electric machine; further comprising ventilation paths, through which the cooling air flows, formed around the outer circumference of the water-cooling unit; wherein after the cooling air has been circulated by the fan in the machine for cooling, the cooling air is led to the ventilation paths to perform heat exchange between the cooling air flowing in the ventilation paths and the water-cooling unit, after which the cooling air is circulated again in the machine.

Common mode choke apparatus and method

Abstract: An embodiment integrated common mode choke comprises a magnetic core, a magnetic plate, a first winding coil and a second winding coil. The magnetic plate is inserted within an inner circumference of the magnetic core. The first winding coil and the second winding coil are wound are wound in the same direction through the magnetic core. The integrated common mode choke is equivalent to a common mode choke and a differential mode choke connected in series. The inductance value of the differential mode choke can be changed by adjusting either the gap between the magnetic plate and the magnetic core or the thickness of the magnetic plate.

Design of coil structure achieving uniform magnetic field distribution for wireless charging platform

Abstract: Wireless power transfer technology via electromagnetic coupling has been widely used in the planar contactless charging platform. In this paper, a current distribution is deduced to ensure axial component of magnetic field is uniformly distributed in the charging region and zero outside the region. Based on continuous current distributions that can generate even axial component of magnetic field, two transmitting coil structures are proposed. The uniformity of the axial component of magnetic field distribution is confirmed by using the simulation tools. In the case of multiple coils in parallel, the magnetic field distribution near the margin of the charging region changes greatly. This paper analyzed the changes of magnetic field in the case of two coils in parallel, and compared the magnetic field distribution with different coil structures.

Transferring electric energy to a vehicle by induction

Abstract: The invention relates to a system for transferring electric energy to a vehicle, in particular to a road automobile or to a track bound vehicle such as a light rail vehicle, wherein the system comprises an electric conductor arrangement (37) for producing a magnetic field and for thereby transferring the energy to the vehicle, wherein the electric conductor arrangement (37) comprises at least one current line (37a, 37b, 37c), wherein each current line (37a, 37b, 37c) is adapted to carry the electric current which produces the magnetic field or is adapted to carry one of parallel electric currents which produce the magnetic field and wherein: - the current line or lines (37a, 37b, 37c) extend(s) at a first height level, - the system comprises an electrically conductive shield (20) for shielding the magnetic field, wherein the shield (20) extends under the track and extends below the first height level, and - a magnetic core (39) extends along the track at a second height level and extends above the shield (20).

A high repetitive rate intense electron beam accelerator based on high coupling Tesla transformer

Abstract: Tesla transformers are widely used in short pulse, repetition pulsed power generators. In this paper, a high repetitive rate intense electron beam accelerator (IEBA) based on high coupling (~1) Tesla transformer, which consists of a primary charging system, coaxial pulse forming line (PFL) charged by Tesla transformer and gas spark switch is described, especially stressed on the high coupling Tesla transformer. By introducing magnetic core to enhance the coupling factor between the primary and secondary windings, the transformer is capable of producing high voltage pulse up to 1.4 MV in approximately 45 µs. A coaxial pulse forming line is closely attached to the transformer that the outer and inner magnetic cores are parts of the PFL's outer and inner conductors respectively. In addition, the parameters of the Tesla transformer and PFL are calculated, including the dimension of the PFL and Tesla transformer. Some experiment results showed that the IEBA is capable of producing electron beams of 300–700 kV/7–13 kA at repetitive rate 100 Hz, with the pulse width 35 ns. The maximal energy efficiency of the Tesla transformer is 83%.

A Linear Doubly-Salient HTS Machine for Wave Energy Conversion

Abstract: This paper proposes a linear doubly-salient high-temperature superconductor (HTS) machine for wave energy conversion, which is composed of a tubular stator and a tubular translator. Since the translator is a simple iron core with salient poles, it is so robust that it can be directly coupled with the reciprocating buoy. The stator consists of an iron core with salient poles, DC HTS field windings and 3-phase HTS concentrated armature windings. By using the finite element analysis, the proposed machine is quantitatively compared with its permanent magnet and copper-winding counterparts. Hence, it validates that its performance, especially the power density, can be improved greatly.

Increase of tape wound core losses due to interlamination short circuits and orthogonal flux components

Abstract: High performance laminated core materials are nowadays used in several different applications, from some Watts to some Megawatts and from some tens of Hertz to some hundreds of Kilohertz. Cutting laminated or tape wound cores in order to obtain a desired geometry results in higher core losses mainly due to the introduction of short circuits between layers of magnetic material and also due to the flux which is perpendicular to the layer plane as given for the fringing field of inductors or the stray field of transformers. This paper verifies the influence of some machining methods on the increase of core losses and shows an approach to keep the effect minimized. Furthermore, the importance of considering core losses due to perpendicular flux is verified for a cut core inductor and a transformer arrangement.

Predicting inductance roll-off with dc excitations

Abstract: Predicting variations in inductance of an inductor under different dc bias current conditions is investigated for several different magnetic core materials. A method is presented that allows this constraint to be incorporated into the optimization of an inductor for power conversion applications. Theoretical predictions of an inductor's saturation characteristics are compared to the measured performance. The method can be based on characteristics from a magnetic material datasheet or on characteristics extracted from measurements.