Olivier Chadebec

MoM and PEEC Method to Reach a Complete Equivalent Circuit of a Static Converter

This paper presents an application of the Method of Moments (MoM), to compute parasitic capacitances of a power electronics layout. By coupling these capacitances to a resistive and inductive equivalent circuit obtained thanks to Partial Element Equivalent Circuit (PEEC) method, a complete electrical equivalent circuit made of lumped elements is obtained. Its simulation by means of a SPICE-like tool enables the evaluation of the EMC efficiency of a power electronics structure. This method is applied to a boost converter and the results obtained by numerical simulation (MoM and finite element method - FEM) are compared to measurements. Finally, radiated EMC investigations are presented thanks to circuit simulation and measurements.

A Mixed Surface Volume Integral Formulation for the Modeling of High-Frequency Coreless Inductors

An original integral formulation dedicated to the high-frequency modeling of electromagnetic systems without magnetic materials is presented. The total current density (i.e., conduction plus displacement currents) is approached by facet elements so that resistive, inductive, and capacitive effects are all modeled. Furthermore, the method avoids the volume mesh of the conductors, which is too dense at high frequencies, due to the skin and proximity effects appearing, e.g., in wound inductors. Surface impedance boundary conditions are employed to that end. The formulation is general and suitable for nonsimply connected domains. It is first compared with the finite-element method on an academic test case, and is then experimentally validated on a coreless wound inductor, using an impedance analyzer.

Fast Models to Predict the Magnetic Stray Field Created by Faulty Electrical Machines

The analysis of magnetic stray field created by electrical machine is now known as a powerful method for fault monitoring. This paper proposes two approaches to compute the magnetic stray field created by faulty electrical machine. The first one presents a homogenized FEM method. The second one is based on a combination of an analytical expression for the magnetic field in the air gap with an integral method. Both models lead to accurate results while saving significantly CPU time and memory, and highly simplify the machine description. Then, it is possible to use them to model electrical machines in faulty operation modes.

Near-field coupling between EMC filter components

A method is proposed to compute the electromagnetic couplings between components in EMC filters. The technique is based on multipolar expansion, which provides a representation of generic structures. A simulation illustrates our approach by computing the mutual inductance between components according to their geometrical placement.

Efficient Reluctance Network Formulation for Modeling Design and Optimization of Linear Hybrid Motor

The aim of this paper is to propose an efficient and unique reluctance network (RN) model for all translator displacements of a linear hybrid motor. This model has to consider several translator positions to analyze the linear motor performances. The proposed RN model takes into account the magnetic characteristic and the flux leakage. Consequently, the proposed model gives precise results of the electromagnetic characteristic. The RN model considers an interesting solution to deal quickly with an optimization task of a large number of constraints and parameters. The developed model is coupled with sequential quadrating programming method for an optimization process of the linear machine. The obtained results confirm the efficiency of this method for modeling and optimization of the linear machine.

Hybrid Natural Element Method-Boundary Element Method for Unbounded Problems

This paper presents a hybrid approach coupling natural element method (NEM) and boundary element method (BEM) for the treatment of unbounded problems. The goal is to combine the accuracy of the NEM and ability of the BEM in modeling linear and deformable domains without a mesh. The performance of the proposed scheme is compared with a finite-element method-BEM coupling in terms of accuracy. Results show that for a given number of degrees of freedom, the proposed approach (NEM-BEM) is able to provide more accurate solutions.

A Fast Model to Predict the Stray Magnetic Field Created by Electrical Machines

This paper deals with a new approach to compute stray magnetic field created by electrical machine. Based on an analytical expression of the magnetic field in the air gap and an integral method, it leads to accurate results while highly simplifying the machine description and saving significantly CPU time and memory

Overview on the Evolution of Near Magnetic Field Coupling Prediction Using Equivalent Multipole Spherical Harmonic Sources

In the electromagnetic compatibility behavior of power electronic converters, parasitic magnetic couplings between components are one of the main causes of dysfunctions or poor filtering. These couplings may be either conducted or near-field interferences. To handle interaction problems, full knowledge of these magnetic couplings is essential. This paper is an overview of the work on near magnetic field interference undertaken in the last 15 years by the International Maxwell Laboratory. This paper details a predictive method that accurately and efficiently calculates near magnetic field coupling between two sources. The method uses near-field multipolar expansion in spherical harmonics of electromagnetic sources to determine close magnetic coupling between two sources from their equivalent models. This paper also shows how theoretical developments of large loop antennas have evolved from the van Veen antenna, a model with only two degrees of freedom, to a more complex model in terms of degrees, order, and types of harmonics. In parallel, it describes developments in the measurement method that provides input to the theoretical model. To illustrate how the research has evolved, we discuss coupling between two complex sources to assess the accuracy of this predictive method.

Circuit realization method for reduced order inductive PEEC modeling circuits

Purpose – The purpose of this paper is to synthesize equivalent circuit obtained from reduced order model of large scale inductive PEEC circuits. Design/methodology/approach – This paper describes an original approach for reducing and synthesizing large parasitic RLM electrical circuits coming from inductive Partial Element Equivalent Circuit (PEEC) models. The proposed technique enables the re-use of the reduced order model in the time domain circuit simulation context. Findings – The paper shows how to use a synthesis method to realize an equivalent circuit issued from compressed PEEC circuits. Originality/value – The coupling between methods PEEC and a compressed method as Fast Multipole Method in order to reduce time and space consuming are well known. The innovation here is to realize a smaller circuit equivalent with the original large scale PEEC circuits to use in temporal simulation tools. Moreover, this synthesis method reduces time and memories for modelling industrial application while maintain...

3-D Hybrid FEM–BEM Using Whitney Facet Elements and Independent Loops

This paper presents a hybrid formulation using Whitney facet elements. This formulation is efficient for the modeling of unbounded 3-D magnetostatic problems. Boundary element method is used to model the unbounded regions and finite element method to model the ferromagnetic ones. Using equivalent circuit representation, the problem is changed, the degrees of freedom becoming magnetic flux in loops instead of faces. As a result, the dimension of the system to be solved is decreased.