ELECTRO MAGNETIC APPLICATIONS, INC EMA  MHARNESS Wizard Tim McDonald, PhD Christel Amburgey May 1, 2014

ELECTRO MAGNETIC APPLICATIONS, INC EMA  Preparation

ELECTRO MAGNETIC APPLICATIONS, INC EMA  Block Diagram of Sample Cable 3 W1109 W1159 We must create unique names for traceability in the analysis for segments, junctions (J) and terminations (T). T01 T02 T03 T04 T05 T06 T07 T08 T09 T10 J01 J02 J03 J04 J05 J06 J07 J08 J09 W1109_J01_T01 W1109_J01_J02 W1109_J02_J03 W1109_J03_T02 W1109_J03_T03 W1109_J02_T04 W1109_J01_J04 W1109_J04_J05 W1109_J04_T06 W1109_J05_T05 W1109_J05_J06 W1109_J06_T07 W1109_J06_J07 W1159_J07_J08 W1159_J08_J09 W1159_J09_T10 W1159_J08_T08 W1159_J09_T09 Lengths between connections are not to scale Sample cable named WCM1109 connected to WCM1159 through a junction

ELECTRO MAGNETIC APPLICATIONS, INC EMA  Compile the Inner Conductor Information First we compile all of the interior connection information from relevant spreadsheets/data. 4 Cable Connections

ELECTRO MAGNETIC APPLICATIONS, INC EMA  Route the Inner Conductor Connections Based on Block Diagram 5 Take each connection and trace through block diagram segments Number of wires TSPs, etc. Connection number Connection type (T=TSP) Gauge

ELECTRO MAGNETIC APPLICATIONS, INC EMA  Compiling Parameters 6

ELECTRO MAGNETIC APPLICATIONS, INC EMA  Compiling Parameters 7

ELECTRO MAGNETIC APPLICATIONS, INC EMA  Probes – Pin Transients 8 For each connection, we would like to probe the pin short circuit (SC) current and open circuit voltage. We choose to probe at end 2 (for this case we should have pin to pin connectivity) and we are choosing to open the circuit at end 2 for open circuit (OC) cases. Again we choose to use the first S0 conductor in the TSP as a SC and the second for an OC.

ELECTRO MAGNETIC APPLICATIONS, INC EMA  Running the Wizard

ELECTRO MAGNETIC APPLICATIONS, INC EMA  Create a Simplified Cable Model in CADfix 10 Define units corresponding to 3D CAD (1” cells from mesh). Use a short dummy length for visualization (5” segments). Define a time step. Construct a lattice around model to mesh (model must be meshed to run MHARNESS Wizard tool). Place all geometry in a set (sall, etc.) to mesh.

ELECTRO MAGNETIC APPLICATIONS, INC EMA  Check Orientation of Lines 11 CADfix Command Ploc sens on Arrow goes from end 1 to end 2 To change orientation Orev linename Once this is completed then put all geometry into a mesh set and mesh

ELECTRO MAGNETIC APPLICATIONS, INC EMA  Start the MHARNESS V4 Wizard 12

ELECTRO MAGNETIC APPLICATIONS, INC EMA  MHARNESS Wizard 13 Filename and Time Step value and number are populated automatic ally but user can modify When using MHARNESS Wizard with full 3D model (not simplified cable model) you can put the set name of the cable you wish to make a MHARNESS input file for if there are multiple cables. For now enter mesh set containing all geometry. Select level of shielding – in this case we have TSP shielding and an overbraid so we have two levels of shielding.

ELECTRO MAGNETIC APPLICATIONS, INC EMA  MHARNESS Wizard 14 Select all cables Select all terminations Select Boundary Conditions for Terminations Note, in the wizard, we are ignoring grounded connectors such as J07. We will put these in manually later.

ELECTRO MAGNETIC APPLICATIONS, INC EMA  MHARNESS Wizard 15 Next the Wizard will highlight each segment in the CAD and request input Input Segment Name End 1 and End 2 names (Slide 11) Note enter 0 for terminations 1 mm default In general, we apply a source to all segments (Unless they are a dummy segment such as what is described on slide 10.) The type of source from EMA 3D is a Segment Current Drive from a datafile. We generally name the source file after the segment it is applied to.

ELECTRO MAGNETIC APPLICATIONS, INC EMA  MHARNESS Wizard 16 After input each segment, you will be asked to input the total number of level 1 (in our case TSP) cables.

ELECTRO MAGNETIC APPLICATIONS, INC EMA  MHARNESS Wizard 17 Now you will be asked to route each TSP cable. You should have the preparation material handy to help keep track of the cables.

ELECTRO MAGNETIC APPLICATIONS, INC EMA  MHARNESS Wizard 18 Select segments cable is routed through Select end points Generally we consider the TSPs shorted to the overbraid and then tied to ground. So 1e-6 (short) or 2.5 mOhm bonding resistance is commonly used. If you accidently miscalculate the number of cables it can be changed by this “Change Number S1 Conductors” button and BACK if you make a mistake

ELECTRO MAGNETIC APPLICATIONS, INC EMA  MHARNESS Wizard 19 Next you will be prompted to enter the gauge and cable type. Standard values will automatically populate – these can be edited if necessary Cable Path is highlighted We generally assume a background of air and a jacket with a dielectric of 3 – but these can be edited

ELECTRO MAGNETIC APPLICATIONS, INC EMA  MHARNESS Wizard 20 Then you are asked to enter the core wire dielectric (again default is 3) and the boundary conditions. In general for lightning transient predictions, we look at short circuit current and open circuit voltage. To do this we must make two separate runs. The short circuit run has all S0 boundary conditions shorted. The open circuit run has end 2 open and end 1 shorted.

ELECTRO MAGNETIC APPLICATIONS, INC EMA  MHARNESS Wizard 21 MHARNESS then asks if the next conductor has the same routing path (if you have 18 conductors with the same routing path this will save you significant time).

ELECTRO MAGNETIC APPLICATIONS, INC EMA  MHARNESS Wizard 22 Make shield larger or smaller Navigate back and forth between segments undo

ELECTRO MAGNETIC APPLICATIONS, INC EMA  Additional Cable Pack Features 23 Visualize existing MHARNESS file (beta) Zoom view Output file when done

ELECTRO MAGNETIC APPLICATIONS, INC EMA  MHARNESS Wizard Maker sure the cables have some extra space even though this is fictitious (MHARNESS requires this). 24 Note the conductor number is also shown - this is important because there is some variation in current depending upon position within the bundle.

ELECTRO MAGNETIC APPLICATIONS, INC EMA  Consideration for Probes 25 For this example cable, we moved all of the probed cables to be closest to the shield (Cable 1) for the segment they are probed at. There is some variance due to cable position but in general the margin applied to the transients should account for this.

ELECTRO MAGNETIC APPLICATIONS, INC EMA  MHARNESS Wizard 26 After packing the cables in Cablepack, the Wizard will highlight each cable and populate input parameters. These parameters should be checked against those calculated previously. Previously for this segment, a resistance of 1.73 mohm/m and a transfer imductance of 1.65 nH were assumed, so we would need to edit these values

ELECTRO MAGNETIC APPLICATIONS, INC EMA  MHARNESS Wizard 27 Connector Conductance Boundary Condition Depiction of Shield (Overbraid) and TSPs We do not use connector conductance for this case (Shielded TSPs) If there was a lossy material between the twisted pairs we can chose to model this using the connector conductance. Values are entered in 1/Ohms (i.e. 2.5 mOhms would be entered as 400 in the conductance matrix).

ELECTRO MAGNETIC APPLICATIONS, INC EMA  MHARNESS Wizard 28 Enter the number of probes:

ELECTRO MAGNETIC APPLICATIONS, INC EMA  MHARNESS Wizard 29

ELECTRO MAGNETIC APPLICATIONS, INC EMA  MHARNESS Wizard 30 And create your.inp file!