1. Sanaa.Zangui, Modeling the near-field coupling of EMC filter components #Systems Simulation#TH-PM-2 1 MODELING THE NEAR-FIELD COUPLING OF EMC FILTER COMPONENTS July 29, 2010 Sanâa.Zangui Laboratoire Ampère Lyon, France Sanaa.zangui@ec-lyon.fr

2. Outline Introduction Aims Equivalent model Validation Summary Questions Sanaa.Zangui, Modeling the near-field coupling of EMC filter components 2

3. Introduction Sanaa.Zangui, Modeling the near-field coupling of EMC filter components 3 In Power electronic => noises Low pass filter => reduce conducted noises(HF) Power electronic system Filter Motor by conduction by radiation Magnitude (dB) Low pass filter Frequency

4. Introduction Magnetic Coupling Analysis (Low voltage/ high current) Near-field Approximation. - Distance between components<< wavelenght λ - Maximum frequency (100MHz) => λ max = 3meters Parasitic parameters and EMC Filter Performances: - Self-parasitic - Filter components coupling. Sanaa.Zangui, Modeling the near-field coupling of EMC filter components 4 Magnitude (dB) 1MHz 30MHz Mutuals inductances Frequency The self-parasitics of components 12 Cy 2 L DM Cy 1 EPC EPR L DM Cy 2 ESR 2 ESL 2 ESR 1 Cy 1 ESL 1 MM 21 M 3

5. Aims Taking into account the effects of parasitic parameters in the first step of designer a filter Equivalent Model Components : –Model the magnetic near-field produced by filter components –Take into account the near electromagnetic environment –Integrated in an electrical circuit software Compute Coupling Effects –Using the equivalent model of components –According to their geometric placement. Sanaa.Zangui, Modeling the near-field coupling of EMC filter components 5

6. Equivalent model (Multipolar expansion) 3D EM fields : multipolar expansion Sanaa.Zangui, Modeling the near-field coupling of EMC filter components 6 The field is computed outside the sphere that contains the equivalent source. n=1 m=0 (dipole)n=2 m=0 (quadrupole)

7. Equivalent model (Equivalent model) The expression of the magnetic field : Q nm are functions of H Computing H by using 3D numerical model or measurement Sanaa.Zangui, Modeling the near-field coupling of EMC filter components 7 n: degree, m: azimuthal order, Y nm : The spherical harmonics functions Q nm are parameters which need to be identified => equivalent model of the radiated field component

8. Equivalent model (Mutual inductance) Using the equivalent radiated field source model. The spheres which contain each of the sources don’t intersect The expression of the mutual inductance is: Sanaa.Zangui, Modeling the near-field coupling of EMC filter components 8 The coefficients of the multipolar expansion of sources 1 and 2 must be expressed in the same reference => translation.

9. Equivalent model (Computing method) Sanaa.Zangui, Modeling the near-field coupling of EMC filter components 9 Component 1Component 2 H 1 field by numerical modeling or measurement H 2 field by numerical modeling or measurement Q 1nm ComputationQ 2nm Computation Equivalent model 1Equivalent model 2 Rotation + translation in the reference1 of Q 2nm => Q’ 2nm Computation of the mutual inductance M in fonction of Q 1nm and Q’ 2nm The translation is based on the “Addition Theorem for Vector Spherical Harmonics”

10. Equivalent model (Numerical modeling) H field by FEM method(Flux3D®) Sanaa.Zangui, Modeling the near-field coupling of EMC filter components 10 Infinite box Sphere of validity Element to modeling Normal component of H => Q nm => equivalent model => mutual inductance To result this case : - Flux3D => 2000 unknows - Multipolar expansion : For n=Nmax=3 =>15unknows For n=Nmax=5 => 35unknows

11. Validation (case 1) Our result was compared to the numerical result computed by FEM(Flux3D cedrat). Two loops, C 1 and C 2 with a radius “Rspire” of 10 cm, separated by r At r =0.2m the error is greater for Nmax=3 than Nmax=5 Sanaa.Zangui, Modeling the near-field coupling of EMC filter components 11 Relative error (%) Mutual inductance(H)

12. Validation (case 2) For the same previous loops C 1 and C 2 For a rotation of 45° around the y axis of the loop C 2 The results are similar to the previous case Sanaa.Zangui, Modeling the near-field coupling of EMC filter components 12 Mutual inductance(H) Relative error (%)

13. Summary Sanaa.Zangui, Modeling the near-field coupling of EMC filter components 13 The method is validated : – Using multipolar expansion => equivalent model of the radiated field of components. –Using the equivalent model to compute the coupling (Mutual inductance) between components. Apply this method to more complex components. Measurement system that measures Q nm components. Couple this method with Partial Element Equivalent Circuit (PEEC)=> filter modeling including all coupling (track/track, components/components, components/track). The cylindrical harmonics can be considered for modeling components such as capacitors or cables. Provide component libraries including models of coupling between power electronic components.

14. Questions 14 Sanaa.Zangui, Modeling the near-field coupling of EMC filter components