EMC Lab Electromagnetic Modeling Using EMC Research Introduction to EM . . . Equivalent Circuits PEEC at LTU PEEC Modeling Examples PEEC Research Project Jonas Ekman Division of EISLAB Dept. Computer Science, Electrical & Space Engineering Lule˚ a University of Technology 2012 Faculty seminar
1. EMC Lab Ask question during the talk! EMC Lab EMC Research The EMC Lab at EISLAB has two main purposes: to serve as a research and Introduction to EM . . . teaching facility and as a resource for the electronic industry in the region. PEEC at LTU Research is performed on electromagnetic simulations using the PEEC (Par- PEEC Modeling Examples tial Element Equivalent Circuit). The EMC lab has a large, fully attenuated, electromagnetically shielded PEEC Research Project chamber. The chamber is equipped with antennas, transmission and receiv- ing equipment covering the frequency range 30 MHz - 6 (best case) GHz. Examples of tests performed at the EMC Lab: • Emission and immunity testing, both conducted and radiated. • Transient testing (ESD, EFT, surge, burst). • Network analyzers, digital oscillocopes etc.
EMC Lab, cont. We used to o ff er to following courses to undergraduate students: EMC Lab • High frequency electronic systems. EMC Research Introduction to EM . . . • EMC Technology. PEEC at LTU • Antennas PEEC Modeling Examples PEEC Research Project Driving licence course We have a basic (mandatory) EMC course for companies who wish to use our lab for (pre-compliance) testing.
2. EMC Research EMC Lab EMC Research • Electric equivalent circuit-based electromagnetic modeling: Introduction to EM . . . – high performance/parallel computing, PEEC at LTU – hybrid methods, and PEEC Modeling Examples PEEC Research Project – for power electronic systems, • Train-related research: – bearing currents and 1 – grounding problems. 1 Ekman and Wisten, ‘Experimental investigation of the current distribution in the cou- plings of moving trains”, IEEE Transactions on Power Delivery, 2009.
Faculty • Jonas Ekman EMC Lab EMC Research • Jerker Delsing Introduction to EM . . . • ˚ Ake Wisten PEEC at LTU PEEC Modeling Examples • Andreas Nilsson PEEC Research Project PhD Students • Danesh Daroui • Sohrab Safavi
3. Introduction to EM modeling & PEEC • We are talking about electromagnetic (EM) modeling or computational EMC Lab electromagnetics (CEM). EMC Research Introduction to EM . . . • CEM is used to: PEEC at LTU – predict high frequency behavior, PEEC Modeling Examples – ensure functionality, PEEC Research Project – understand the performance or bottlenecks of electrical interconnects and packaging, – calculate EM fields, – develop design guidelines, • Several di ff erent methods: FDTD, FEM, MTL, TLM, MoM, FIT, PEEC. • Due to mathematical di ff erences, di ff erent methods are suitable for specific types of problems ) Use the right method for the right problem. • EISLAB is developing PEEC since it is an electric equivalent circuit ap- proach and we can integrate that with other SPICE-type of work that is going on within the division.
3.1. The Partial Element Equivalent Circuit Method 3.1.1. Basic theory EMC Lab The theoretical derivation starts from the expression of the total electric field EMC Research in free space as Introduction to EM . . . PEEC at LTU r, t ) � @ ~ A ( ~ r, t ) E T ( ~ ~ r, t ) = ~ E i ( ~ PEEC Modeling Examples � r � ( ~ r, t ) . (1) @ t PEEC Research Project If the observation point, ~ r , is on the surface of a conductor, the total electric E T = ~ field can be written as ~ J ( ~ r,t ) , in which ~ J ( ~ r, t ) is the current density on � a conductor. To transform into the electric field integral equation (EFIE), the definitions of the electromagnetic potentials, ~ A and � are used. K Z X ~ r 0 ) ~ A ( ~ r, t ) = µ G ( ~ r, ~ J ( ~ r 0 , t d ) dv k (2) v k k =1 K 1 Z X � ( ~ r, t ) = G ( ~ r, ~ r 0 ) q ( ~ r 0 , t d ) dv k (3) ✏ 0 v k k =1 Combining results in the well known electric field integral equation.
The EFIE to be solved ~ r 0 ) @ ~ J ( ~ r, t ) Z J ( ~ r 0 , t d ) dv 0 + r Z ~ EMC Lab E i ( ~ r, t ) = + µ G ( ~ r, ~ G ( ~ r, ~ r 0 ) q ( ~ r 0 , t d ) dv 0 (4) @ t � ✏ 0 EMC Research v 0 v 0 Introduction to EM . . . Interpreting the EFIE as KVL PEEC at LTU PEEC Modeling Examples It is possible to interpret each term in the above equation as KVL since PEEC Research Project V = RI + sLpI + Q/C (5) This results in interpreting: • The first RHS term as Resistance, • The second RHS term as Partial inductance • The third RHS term as Coe ffi cient of potential
The resulting equivalent circuit for a thin wire EMC Lab EMC Research Introduction to EM . . . R mm Lp Lp mm mm mm PEEC at LTU � � PEEC Modeling Examples PEEC Research Project C �� C �� �� �� Figure 1: One way of visualizing the interpretation of the EFIE as a partial element equivalent circuit (quasi-static approximation).
The resulting equivalent circuit for a thin wire (FW) EMC Lab EMC Research Introduction to EM . . . L PEEC at LTU V R mm Lp mm mm I PEEC Modeling Examples � � PEEC Research Project j I i I C C 1 1 j I i I P P ii P jj P Figure 2: One way of visualizing the interpretation of the EFIE as a partial element equivalent circuit (full-wave = taking care of delays).
3.2. Simple PEEC model for two wires in free space EMC Lab EMC Research Introduction to EM . . . PEEC at LTU I i P PEEC Modeling Examples PEEC Research Project (a) L L V V R mm R mm Lp mm mm Lp mm mm I I � � � � j j I i I i I C I C C C 1 1 1 1 j j I i I i I i I P I P P P ii P jj P ii P jj P P (b) Figure 3: PEEC model for two conducting wires (a) using controlled voltage- and current- sources to account for the electromagnetic couplings (b).
c EMC Lab b EMC Research Introduction to EM . . . PEEC at LTU PEEC Modeling Examples a PEEC Research Project (a) � 3 V 3 L Lp 33 � I 3 + - 2 3 I p 2 4 V 2 V I p L L - + - + 1 3 I p p 22 P 33 L 1 2 I p P 22 Lp 44 I 2 � I 1 1 Lp 11 1 V 1 L I 4 I p - + � 4 1 1 4 I p I p P 11 1 4 I p P 44 (b) Figure 4: Nonorthogonal metal patch (a) and PEEC model (b).
c EMC Lab EMC Research b Introduction to EM . . . PEEC at LTU PEEC Modeling Examples PEEC Research Project a (a) Lp 33 C 23 C 33 Lp 22 C 22 C 13 Lp 44 C 12 L C 24 C 34 p 11 C 11 C 14 C 44 (b) Figure 5: Nonorthogonal metal patch (a) and QS-PEEC model (b).
c EMC Lab b EMC Research Introduction to EM . . . PEEC at LTU PEEC Modeling Examples a PEEC Research Project (a) Lp11 1 4 { Lp 11 value } C11 1 0 { C 11 value } Lp22 1 2 { Lp 22 value } C22 2 0 { C 22 value } Lp33 2 3 { Lp 33 value } C33 3 0 { C 33 value } Lp44 4 3 { Lp 44 value } C44 4 0 { C 44 value } q { Lp 13 value } 2 K13 Lp11 Lp33 C12 1 2 { C 12 value } { Lp 11 value }{ Lp 33 value } q { Lp 24 value } 2 K24 Lp22 Lp44 C13 1 3 { C 13 value } { Lp 22 value }{ Lp 44 value } C14 1 4 { C 14 value } C23 2 3 { C 23 value } C24 2 4 { C 24 value } C34 3 4 { C 34 value } (b) Figure 6: Nonorthogonal metal patch (a) and SPICE .cir-file in (b).
3.3. Example of structure possible to study with the PEEC formulation - in SPICE! EMC Lab EMC Research Introduction to EM . . . PEEC at LTU PEEC Modeling Examples PEEC Research Project
3.4. Summary of approach • Pros: EMC Lab EMC Research + Same time- and frequency- domain model. Introduction to EM . . . + Direct inclusion of other SPICE circuit elements. PEEC at LTU + Solvable with SPICE-like solvers. PEEC Modeling Examples + Engineering-type of approach. PEEC Research Project • Cons: - Large number of partial elements (speed-up, approximations). • Current academic cooperation within CEM: 2. Giulio Antonini, University of L’Aquila. 3. G¨ oran Engdahl, KTH. • Industry (current and past) cooperations with: ABB, Volvo, BMW, Bosch,..
4. PEEC at LTU 4.1. History EMC Lab EMC Research 1999-2001 Introduction to EM . . . Hand calculations + PSpice ) Matlab/Java-routines + PSpice. PEEC at LTU PEEC Modeling Examples Lesson learned PEEC Research Project If you feel that you are stuck, stuck, stuck......get help or get out! 2001-2004 Cooperation with UAq. Start with C++ solver with Lp and P calculations from IBM. All-in-one (solve circuit equations=no PSpice). 2004-2007 New solver (PETSc). All-in-one (solve circuit equations=no PSpice). New solver (GMM++) + parallel-PEEC. All-in-one (solve circuit equations=no PSpice). Post-processing in Matlab. Pre-processing in various CAD-formats (Gerber). 2008- GMM++ going to Intel MKL going to PARDISO and MUMPS and then...
2010- ABB developing an internal graphical user interface to our solver (now called EMC Lab MultiPEEC). Internal e ff orts on interfacing OrCAD. EMC Research Introduction to EM . . . 2012- PEEC at LTU Working on project funding! PEEC Modeling Examples PEEC Research Project
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