A dynamic core loss model is proposed to estimate in both soft ferromagnetic and power ferrite materials with arbitrary flux waveforms. The required parameters are the standard coefficients that either directly provided by manufacturers or extracted from curve associated sinusoidal excitation. applied calculating two-dimensional three-dimensional transient finite element analysis, results compared measured data.

This paper presents a linearized demagnetization model taking into account temperature dependence of the hard magnetic material. At same time, an efficient searching algorithm is proposed to properly identify new worst working point and update recoil line during entire transient solution process if discovered below knee current line. further extended take irreversible behaviors.

We present an approach for directly coupling transient magnetic fields and electric circuits. The circuit can contain arbitrarily connected solid conductors located in the field region. A systematic procedure suitable both nodal method loop is used to couple structures of system equations two methods are analogous. formulations allow stranded windings be unified coefficient matrix symmetrical. In order reduce solution domain, periodic boundary conditions still applicable when involved. Our...

We present a general approach to directly couple finite-element models with arbitrary electric circuits for application electromagnetic devices. describe both two-dimensional (2-D) and three-dimensional (3-D) transient models, emphasis on 3-D using T-/spl Omega/ formulation. For circuit coupling, the derivation of induced voltage is an integral part coupling approach, links magnetic field electrical together. The system created automatically. Then graph theory used deduce by tree/cotree loop...

An indirect procedure to couple transient finite-element simulation with circuit is proposed. The based on extracting lumped parameters from the field and Norton equivalents simulation. This approach provides more stability accuracy because both winding currents terminal voltages across coupling branches are free change. It also flexible since equations solved separately allows complicated system level

An improved vector play model for magnetic hysteresis materials is proposed, and its required parameters are identified from the input major loop. Validation results show that this new improves accuracy of core loss computation not only rotating fields but also alternating compared with ordinary models. The presented has been successfully implemented in 2-D 3-D transient finite element analysis (FEA). Some application FEAs presented.

The measurement of real and apparent power derating three-phase transformers is important for feeding nonlinear loads. This paper presents a new digital data-acquisition method measuring reactive demand under full or partial load conditions. accuracy requirements the instruments employed (potential, current transformers, shunts, voltage dividers, optocouplers volt- meters) are addressed. Application examples demonstrate usefulness this method.

We have developed a dynamic analytical circuit model to simulate the performance of switched reluctance motors (SRMs). Our expresses flux linkages as multiple decoupled one-argument functions, either current dependent or rotor position dependent, instead one two-argument function on both and position. propose novel approach for computation air gap permeance at various positions. By using this model, SRM can be simulated very efficiently with improved accuracy. As an application example, we...

An accurate and efficient nonlinear anisotropic model for soft magnetic materials is developed. In this model, the cross effects of field in different principle directions are decoupled by introducing an equivalent magnitude each direction. This equivalence based on characterization energy density. Only B-H curves principal materials-two two-dimensions or three three-dimensions-need to be measured. The behavior laminations with either isotropic steel also considered. validated numerical...

The definition of energy/coenergy in permanent magnets (PMs) is still dispute when virtual work used to compute magnetic forces using finite-element methods. There also no current practical method for computing PMs touch objects. These problems are addressed this paper terms a new and by shell elements. results verified analytical computations.

The online monitoring of iron-core and copper losses single- three-phase transformers is important, particularly for feeding nonlinear loads. This paper devises a new digital data acquisition method the separate measurement under any full or partial-load conditions. accuracy requirements instruments (voltage current sensors, voltmeters, ammeters) employed are addressed. uncertainties acceptably low if voltage sensors with 0.1%-0.5% used.

We present a new approach to computing cogging torque based on only one analytical field solution in surface-mounted permanent-magnet (PM) motors. use conformal transformation compute the magnetic created by permanent magnets air gap with single slot. Then, we derive due single-slot effect at different rotor positions directly from 2-D solution. The total is synthesized contribution of each have applied our predicting two PM motors, 4 poles, 24 slots and other 42 36 slots. predicted torques...

A three-dimensional (3D) transient finite element analysis (FEA) approach taking into account the effects of steel lamination core loss is proposed. When using T-Ω method, are considered by introducing an additional field component in regions, which derived from instantaneous time domain. The proposed validated two applications terms power-balance testing, that is, input power increase due to core-loss must be equal total loss.

An efficient method is proposed to predict eddy current loss of Litz wire coils, or completely transposed multi-strand in transient finite element analysis (FEA). The based on analytical solutions a solid due skin effects and proximity effects. bundle wires homogenized by introducing fill factor describe the conducting area ratio. frequency domain for round, square, rectangular are further expanded those time domain. length direction each 3-D mesh automatically detected so that flux density...

It has been observed that the presence of DC bias currents/fluxes in power transformers generates harmonic currents and voltages with an associated increase reactive (kVAr) demand resulting a voltage drop. Such biases can occur: near high-voltage (HVDC) terminals; due to imperfect or half-controlled rectification DC, even odd harmonics; because geomagnetically induced currents; as consequence nuclear explosions changing Earth's magnetic field; rectifiers working normal (e.g., half-wave)...

Parameters of a capacitor-start, capacitor-run single-phase induction motor with closed or semi-closed rotor slots are measured and model for the investigation performance machine in frequency domain under influence harmonic voltages is presented. An algorithm, taking into account nonlinear leakage inductance, established. This algorithm applied to estimate current time domain, losses at rated-load operation without run capacitors calculated. Computational results compared those from...

An automatic cut generation algorithm based on the tree/co-tree technique is presented for treating multiply connected regions in 3D transient solutions including rigid motion. In cutting domains, zero curl condition of vector potential strongly imposed. As part algorithm, a separation introduced to confine each domain either stationary or moving nonconforming mesh coupling and reducing computational cost.

In this paper, a new approach is presented for extracting saturated parameters Ld , Lq and permanent-magnet flux linkage λ <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">md</i> with arbitrary load conditions interior (IPM) synchronous machines. The procedure starts the parameter extraction in actual xmlns:xlink="http://www.w3.org/1999/xlink">abc</i> reference frame based on transient finite element analysis (FEA) time domain. Then, are...

Irreversible thermal demagnetization effects can sometimes play a significant role in, for instance, rotating Preisach model (PM) machines. Modeling such phenomena requires field simulation methods as finite element (FE) analysis in combination with temperature-dependent vector hysteresis model. This paper explores the feasibility of applying formalism structural to magnetics. The net magnetization is expressed superposition contributions from plays. By allowing anhysteretic curve and...

As a follow-up to our previous effort consider the effects of steel lamination core loss on 3-D transient magnetic fields, new algorithm is proposed eliminate possible convergence problems and improve computation efficiency when strong eddy core-loss component involved. The approach validated by two application examples in terms power-balance testing, that is, increase input power between considering without must be equal total losses.

The torque constant, together with the back-EMF was originally used in permanent-magnet DC commutator (PMDC) motors to couple electric circuit equations mechanical equations. It is still an open question how these two constants should be defined brushless (BLDC) and (PM) AC motors. We present in-depth study of constants, conclude that definition based on <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dq</i> axes applicable for dynamic motion...

A generalized analytical field solution by conformal transformation is presented for calculation of no-load magnetic distribution in the slot-less and slotted air gap spoke-type permanent magnet (PM) machines. These solutions are used to predict cogging torque PM motors. The computed using proposed method compared with results from 2D finite element analysis (FEA) three application examples.