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LAT Environmental Test Planning and Design Review 3-4 May 2005 EMI/EMC

LAT Environmental Test Planning and Design Review 3-4 May 2005 EMI/EMC. Michael N. Lovellette. LAT EMI Test. LAT test levels derived from 433-RQMT-0005_RevA & LAT-SS-0778 Draft EMI/EMC Test Plan: LAT-MD-00276-02 Use CAL EMI test procedure as template LAT-PS-03929-03 Test Suite:

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LAT Environmental Test Planning and Design Review 3-4 May 2005 EMI/EMC

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  1. LAT Environmental Test Planning and Design Review 3-4 May 2005 EMI/EMC Michael N. Lovellette

  2. LAT EMI Test • LAT test levels derived from 433-RQMT-0005_RevA & LAT-SS-0778 • Draft EMI/EMC Test Plan: LAT-MD-00276-02 • Use CAL EMI test procedure as template • LAT-PS-03929-03 • Test Suite: • CE102 Conducted Emissions, Power Leads, 10 kHz to 10 MHz, MIL-STD-462, CE03 • CECM Conducted Emissions, Time Domain, 150 MHz Bandwidth • CS102 Conducted Susceptibility, Power Leads, 10 kHz to 10 MHz, MIL-STD-462, CS02 • CSCM Conducted Susceptibility, Common Mode, 30 Hz to 150 MHz, MIL-STD-462, CS02 • CS06 Conducted Susceptibility, Spike, Power Leads, MIL-STD-462 • RE101 Radiated Emissions, Magnetic Field, 20 Hz to 50 kHz • RE102 Radiated Emissions, Electric Field, 10 kHz to 18 GHz, MIL-STD-461E • RS101 Radiated Susceptibility, Magnetic Field, 20 Hz to 50 kHz • RS103 Radiated Susceptibility, Electric Field, 30 MHz to 18 GHz

  3. LAT Power Interfaces • SC-LAT Power Interfaces • SC PRU (P) - LAT PDU • SC PRU (R) - LAT PDU • SC PRU (P) - LAT SIU (P) • SC PRU (R) - LAT SIU (R) • SC PRU (P) - LAT VCHP +Y • SC PRU (P) - LAT VCHP -Y • SC PRU (R) - LAT VCHP +Y • SC PRU (R) - LAT VCHP -Y • SC PDU (P) - LAT MAKEUP • SC PDU (R) - LAT MAKEUP

  4. Test Limitations • Deviations from nominal test • RS103 upper limit of 18GHz (40GHz) • Limited area of RS101 test • Requires scanning each 10cm x 10cm area, ~16min/scan • ~1450 scans for the LAT, another ~1200 for the radiators (~29 days) • Scan selected locations around connectors, PMTs, BEA • LAT EGSE power supplies will be used for all EMI/EMC testing, no attempt will be made to duplicate expected characteristics of the S/V power • Limited B side conducted testing • Emissions tests and susceptibility only where noted on A side • No heater circuit testing

  5. Open Issues • Replace CSCM as run for CAL EMI with MIL-STD 461E CS114 derived CSCM test • Update RE102 limits per proposal from Fred Blanchett

  6. EMI Test Configurations • Split EMI test • Conducted tests performed in the high bay integration area • Radiated testing performed in anechoic chamber • Conducted emissions and susceptibility tests with SIU and PDU do not require radiators, but do require good access to connectors

  7. Radiated Test Configuration

  8. MGSE/STE for EMI/EMC Testing • LAT (on the TIP) is mounted on the Test Stand for EMI/EMC testing • LAT + TIP mounts to Test Stand • Radiators are not yet integrated for this test, since they are not part of the EMI/EMC Test Plan • LAT is rolled into the anechoic chamber • Dust Tent remains over the LAT for the entire operation, including during testing • Auxiliary cooling is needed during the test, since the LAT will be on for the entire test duration Test Interface Plate LAT Radiators not yet integrated for this test Test Stand EMI/EMC Test Configuration

  9. LAT Radiated Test Configuration

  10. MGSE Requirements Flowing from EMI/EMC Test Plans • See the table, below, for a list of all MGSE/STE that is needed for conducting the EMI/EMC test • Test Stand • Provides clear access around the perimeter of the LAT for positioning antennae during the test • Provides clear access directly under the LAT for positioning an antenna • Dust Tent • Capable of providing clean, dry environment before/during/after EMI/EMC testing • Provides clearance around LAT • Does not impact the radiated emissions or susceptibility tests (must be essentially transparent to EM radiation in frequency range of tests) • Chill Bars and Auxiliary Cooling system • Operated during the test MGSE/STE Needed for EMI/EMC Testing

  11. Auxiliary Cooling and Mechanical Handling • Auxiliary cooling plans • LAT needs to be cooled during the entire duration of EMI/EMC testing • Chill Bars: one under each of the two X-wings on the Grid • X-LAT Aux Cooling: using fly-away cooling lines already mounted to X-LAT Plate • This is room-temperature cooling to remove LAT process heat • Fluorinert FC-77 working fluid is a dielectric, and hoses are non-conducting, so the chiller system will be electrically isolated from the LAT • Handling and mechanical operating procedures • LAT lifting procedure • Test Stand handling and operating procedure • Dust tent handling and operating procedure • LAT auxiliary cooling system operating procedure

  12. MGSE Issues for EMI/EMC Testing • Dust Tent • This is needed for EMI/EMC testing, because of the dirty conditions outside the test cell, and the potential for particulates to rain off the overhead anachoic foam • Dust tent will need to be designed to be essentially transparent to EM radiation in frequency range of tests • Transportation issues • The EMI/EMC chamber is a long way from our high-bay “home base” • Transportation route is circuitous and floor surfaces are of varying quality • Need to load-test a wooden trestle over abandoned railroad tracks • We plan to pathfind this route to ensure there are no problems in maneuvering the LAT • The EMI/EMC chamber has a ¾” door sill/threshold • We plan to build a ramp to roll up and over the sill • This will definitely by prototyped with the pathfinder, since the LAT c.g. is moderately high

  13. Conducted Test Considerations • Fully test: • SC PRU (P) - LAT PDU • SC PRU (P) - LAT SIU (P) • Limited test: • SC PRU (R) - LAT PDU • SC PRU (R) - LAT SIU (R) • Conducted susceptibility tests may require changing bus protection unit settings

  14. Conducted Test Harness • Require access to power harness ~2 m from LAT I/F • CE102, CS102 (10kHz - 150kHz), CSCM (30Hz - 150kHz), CECM • All conductors of power circuit must be connected to a single 1/4” lug on line conditioner • All conductors must be gathered into a bundle so that a current probe may be connected around them • Require access to power harness ~5cm for LAT I/F • CS102 (150kHz - 150MHz), CS06, CSCM (150kHz - 150MHz) • Small bare section of a single conductor to attach clip lead for hf injection • EMI shielding not required on breakout harnesses • Harness specification in work • See R. Bielawski talk

  15. Radiated Test Harness • No access to conductors required • Harness must be fully shielded • Includes all connector savers • Any test ports must be closed out or have shielded harnesses • “back door” • Test harnesses must be shielded • Accelerometers • TCs & thermistors • Harness supports not directly connected to the LAT should be nonconducting material, wood or PVC

  16. Grounding • All LAT EGSE must be capable of ≤2.5mOhm connection to facility ground • BPU • VSC • Computers • Chiller must be connected to LAT via nonconducting tubing • Chiller chassis must be capable of ≤2.5mOhm connection to facility ground • LAT and or LAT MGSE must have ground points on all four sides capable of ≤2.5mOhm connection to facility ground • To obtain grid to ground ≤2.5mOhm

  17. Test Software • Emissions Testing • Utilize the FSW Charge Injection Calibration function to inject charge into a large number of detectors. The number of channels into which charge can be injected will be limited by: a) FSW design (whichisnot yet complete); and b) The number of channels which can physicallybeinjected with charge in any given one second cycle. The one second cycle is required to provide repeatability during the Emissions frequency sweeps. • Susceptibility Testing: • Avariation of the test described in the End-to-End (ETE) Test Plan, LAT-MD-03489, paragraph 2.2.1, item 4, "Nominal Rate Cosmic Ray Test" will be used. This test is run at ambient temperature and at nominal voltage, timing, threshold, and trigger configurations.Both Cosmics and the external trigger functionare usedto create on-orbit trigger rates. The external trigger ratewillbe set so thatthe total trigger ratewill be at or near thenominal expected on-orbit values. • The externally triggered events should have very low occupancy, monitor to see if occupancy goes up • The cosmic ray events should remain constant, monitor to see if rate goes up. • Need real time continuous go/no go

  18. Test EGSE Software Tools • Displays of natural trigger rates and occupancy of externally triggered events should be strip chart type • Other error status, checksum, etc. should latch

  19. RE101 – All LAT Equipment

  20. RE102 - Integrated LAT

  21. CE102 Spacecraft PRU – LAT DAQ

  22. CE102 Spacecraft PRU – LAT SIU

  23. Conducted Emissions Common Mode – All LAT Equipment

  24. RS101 Perform – BEA and Tracker Tower

  25. RS103 Perform – BEA and Tracker Tower

  26. CS102 Spacecraft PRU – LAT DAQ

  27. CS102 Spacecraft PRU – LAT SIU

  28. Conducted Susceptibility Common Mode – All LAT Equipment

  29. CS06 Operate – All LAT Equipment

  30. CS06 Perform – All LAT Equipment

  31. Action Items

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