• The Challenge EM Simulation

    The Challenge EM Simulation

    Are you faced with such tasks: Are innovations permanently required? Measurements and experiments are not satisfactory? Is the Physics Complex? Time is short? Then we are here for you! On these pages we demonstrate MAGNETICS, an outstanding electromagnetic FE solver product that we develop for you. MAGNETICS, integrated in NX / Simcenter or as standalone, well known as NX Magnetics, is a comprehensive FEM software package to simulate and optimize electromagnetic devices. It is used by industry and science and either Read More
  • Circuit Breakers

    Circuit Breakers

    Outstanding Features for the coupling of electromagnetic, elasticity, motion and thermal allow realistic simulations of circuit breakers and switchgears. The animation demonstrates the FEM simulation of a low-voltage circuit breaker. A voltage is applied to a coil (below), whereupon the plunger is pulled into the coil. The four contact bridges (above) are connected to the plunger and then press on their contact partners, whereupon the AC current flows through the lines. The Lorenz forces lead to small mechanical vibrations with Read More
  • High-Frequency

    High-Frequency

    Thanks to the capability of a full wave solver, the analysis of antennas, waveguides or microwave ovens is another application area for electromagnetic simulation with Magnetics for NX/Simcenter. The picture shows as an general example the model of a microstrip patch antenna and its electric field result. Such antennas are becoming increasingly useful because they can be printed directly onto a circuit board. They are becoming very widespread within the mobile phone market. Patch antennas are low cost, have a Read More
  • Individual Motor Designs

    Individual Motor Designs

    The application to simulate is a linear motor to be used in a future magnetic levitation railway. We publish this with kindly permission by HARDT GLOBAL MOBILITY. Download as PDF Read More
  • Transformers

    Transformers

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  • Lightning Strikes

    Lightning Strikes

    Lightning strikes that occur in wind turbine towers can be analyzed to help for dimensioning of arrestors and to estimate the electric and magnetic field strengths that appear.This example shows how this kind of analysis can be done in Magnetics for NX/Simcenter. The tower is made of steel bars that conduct the lightning current down into the ground. Inside is a cable with an resistor in which we want to analyze the specific energy. Download as PDF Download NX Files Read More
  • EMC, Electromagnetic Compatiblity

    EMC, Electromagnetic Compatiblity

    This example shows a FEM analysis of a Circuit Breaker that is placed in a carbon fiber box. Induced eddy currents and the shielding effect are investigated. Download as PDF     Download NX Files Video Read More
  • Customer Presentations

    Customer Presentations

    Following we demonstrate some presentations or papers published by industrial users and ourselves. Optimierung eines PMSM Motors bezüglich Drehmoment und Ripple mit NX Magnetics und HEEDS. Presentation of Peter Binde at 2022 PLM Connection. Electrostatic discharge simulation using a GPU-accelerated DGTD solver targeting modern graphics hardware. COMPUMAG 2021. Jan. 16-20, 2022, Cancun, Mexico conference paper, Matteo Cicuttin, Anthony Royer, Peter Binde and Christophe Geuzaine.We discuss an implementation on recent GPU hardware of the Time Domain Discontinuous Galerkin method for the Read More
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EMC on a Carbon Fiber Shielded Circuit Breaker

This example shows a FEM analysis of a Circuit Breaker that is placed in a carbon fiber box. Induced eddy currents and the shielding effect are investigated.

Download as PDF     Download NX Files

Video

Initial Situation

EMC Shielding with Fiber Materials

In industries like energy management of buildings, also in automotive (e-cars) or aircrafts the assemblies and surrounding geometry are influenced by electromagnetic fields produced by electronic components like circuit breakers or electric motors.

Picture: Typical Circuit Breaker AssemblyPicture: Typical Circuit Breaker Assembly

For choosing the best geometry, cooling, materials and operation conditions it is necessary to know how large the field strengths become outside shielding boxes and at various distances. Although there do exist effective ways for EMC shielding for example using mu metals today many parts must be manufactured of carbon fiber or other complex materials. Prototypes are expensive and too time consuming so simulations must be performed.

Picture: CAD Model of investigated Circuit BreakerPicture: CAD Model of investigated Circuit Breaker

In this study a circuit breaker under short circuit condition is analyzed for the electromagnetic field and how this field is shielded by a box that is made of carbon with orthotropic fiber directions. Goal is to find the magnitude of the magnetic flux density at various position in and outside the box.

Appropriate Method

Transient Dynamic with conducting orthotropic Sheets

The analysis starts from an NX CAD model that contains the coil, the plunger and several small sheet metals from the circuit breaker. There is a shied box around the circuit breaker which has openings for input and output wires. This box is a sheet body while the rest is solid geometry. Also the air volume is in the CAD model.

Several finite element meshes are created in NX. All of them are given material properties as it is usual in electromagnetic analysis with NX Magnetics.

Picture: 3D FEM meshes that are used to model the Circuit Breaker GeometryPicture: 3D FEM meshes that are used to model the Circuit Breaker Geometry

The shield box is meshed with 2D elements using the Physical property Conductive Sheet which allows to model thin conducting sheets. Coordinate systems define the directions of the orthotropic material.

Picture: FEM Model of the Box. Due to thin Geometry we have set up the box with 2D Sheet Elements. Material is orthotropicPicture: FEM Model of the Box. Due to thin Geometry we have set up the box with 2D Sheet Elements. Material is orthotropic

To model the carbon fiber we apply an orthotropic material with 3 different electric conductivity values. In direction of fiber 200000 S/m is applied while the others directions have a small value. Using local coordinate systems the orthotropic material is oriented on the 6 faces of the shield box. The picture shows this definition in NX’ material editor.

Picture: The Material Properties that we give to the Box ElementsPicture: The Material Properties that we give to the Box Elements

In the Sim file we define transient current on the wire’s end caps. We apply the following analytic formula which forces short circuit conditions:

2^0.5*100*(Sin[2*Pi*50*$Time-1.57]+Exp[-$Time/0.0455]*Sin[1.57])

We run 30 time steps with an increment of 0.1/150 s. The model has about 500000 degrees of freedom, needs 16GB memory and the solve job takes about 30 min of an Intel i7 with 4 cores machine.

Result

Eddy Currents and B Field

The computed field solution contains results for each time step. We have requested eddy currents and the magnetic flux density. The following pictures illustrate the solution.

First we want to see the eddy currents on the shielding box. The next pictures show them in contour and vector plot.

Picture: Eddy Currents on the carbon Shielding BoxPicture: Eddy Currents on the carbon Shielding Box

To get an understanding of where the induced currents in the box come from we want to see the circuit breaker together with the box in one picture. This is shown in the next picture.

Picture: Eddy Currents on the carbon Shielding Box and the Breaker GeometryPicture: Eddy Currents on the carbon Shielding Box and the Breaker Geometry

Next we want to see how the magnetic field is shielded by the carbon box. Therefore we place a section of the view and overlay that in a new picture (see next two pictures).

Picture: A section through the Air volume shows the Magnetic Flux Density. The shielding effect of the Carbon Box is visiblePicture: A section through the Air volume shows the Magnetic Flux Density. The shielding effect of the Carbon Box is visible

Picture: Another section through the Air volume shows the Magnetic Flux DensityPicture: Another section through the Air volume shows the Magnetic Flux Density

 

 

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