EMC - EV

Electromagnetic Compatibility for Electric Vehicles

EMC-CS-2009.1 CI 210 (Us Vp-p calibration issue)

ES-XW7T-1A278-AC Immunity from Continuous Disturbances: CI 210

This test refers to continuous disturbances produced by vehicle’s charging system that can affect DUT functions.



FMC1278 Rev2 vs EMC-CS-2009.1 - CI 210 Requirements

  • Level 2 requirements, as delineated in ES-XW7T-1A278-AC was removed in EMC-CS-2009.1, then added back in FMC1278.
  • The frequency range allocated for severity levels was changed subsequently in all three Ford EMC specifications.
  • The most significant differences for Us Vp-p requirements occurred between  ES-XW7T-1A278-AC & EMC-CS-2009.1.


CI 210 Frequency Steps

The most significant differences in frequency steps requirements occurred between  ES-XW7T-1A278-AC & EMC-CS-2009.1.


ES-XW7T-1A278-AC CI 210: Test Setup
  • The test harness connecting the DUT to the Test Fixture and transient pulse generator shall be < 2000 mm in length.
  • The DUT and wire harness shall be placed on an insulated support 50 mm above the ground plane. If the outer case of the DUT is metal and can be grounded when installed in the vehicle, the DUT shall be mounted and electrically connected to the ground plane.

ES-XW7T-1A278-AC CI 210: Test Procedure

  1. Adjust DC offset of the signal generator/audio amplifier to 13.5 volts with the DUT disconnected (open circuit)
  2. At each test frequency set and record the signal generator output to the specified voltage level with the DUT disconnected (open circuit).
  3. Without the test signal present, connect the DUT and verify that it is functioning correctly.
  4. Apply the test signal to the DUT and the Test Fixture such that all power and control circuits are exposed to the disturbance. All power and control circuits are tested simultaneously.
EMC-CS-2009.1 CI 210: Test Setup

  • The test harness connecting the DUT to the Load Simulator and modulated DC supply shall be < 2000 mm in length.
  • All DUT power/power return circuits shall be connected together at the modulated power supply.
  • Per previous versions of this requirement, a ground plane may be placed under the DUT and Load Simulator, but if used, the DUT and wire harness shall be placed on an insulated support 50mm above the ground  plane. Additionally, the negative connection of the modulated DC supply and case of the Load Simulator shall be referenced to the ground plane.


EMC-CS-2009.1 CI 210: Test Procedure

  1. Without the DUT connected, adjust the DC voltage offset "Up" of the modulated power supply to 13.5 volts. Initially set the AC voltage amplitude "Us" to zero volts.
  2. Connect and activate the DUT and verify it is functioning correctly. Verify that Up remains at 13.5 VDC. Adjust the supply as required to achieve this voltage level.
  3. At each test frequency increase Us to the corresponding stress level while the DUT is operating. The dwell time shall be at least 2 seconds. A longer dwell time may be necessary if DUT function response times are expected to be longer. This information shall be documented in the EMC test plan.
FMC1278 CI 210: Test Setup

  • The test harness connecting the DUT to the Load Simulator and modulated DC supply shall be < 2000 mm in length.
  • All DUT power/power return circuits shall be connected together at the modulated power supply.



FMC1278 CI 210: Test Procedure

  1. Without the DUT connected, adjust the DC voltage offset "Up" of the modulated power supply to DUT’s system voltage (13.5, 27 volts). “Us” is initially set to zero volts.
  2. At each test frequency adjust and record the signal generator output required to achieve the specified modulation voltage level “Us” with the DUT disconnected (open circuit). Use the frequency steps listed.
  3. Without the modulation signal present (i.e. Us = 0 volts), connect the DUT and verify it is functioning correctly.
  4. At each test frequency, apply the signal generator levels recorded in step (2) to the DUT and the Load Simulator such that all power and control circuits are exposed to the disturbance. The dwell time shall be at least 2 seconds. A longer dwell time may be necessary if DUT function response times are expected to be longer. This information shall be documented in the EMC test plan and test report.
Fixing EMC-CS-2009.1 CI 210 Us (Vp-p) calibration issue:

CI 210 test waveform is not the superimposed alternating voltage per ISO 16750-2. 
Prior to test Us is calibrated (substitution method) to maintain the required Us V(p-p) while DUT is driving high current loads (e.g. 30A): at each test frequency increase Us to the corresponding stress level while the DUT is operating. The amplifier (e.g. Techron 7796) is configured to operate as Voltage-Controlled Source. Whenever functions are paused between activations (very low current) the amplifier will increase its output voltage in an attempt to drive the requested current into DUT as recorded during Us (Vp-p) calibration. This will result in high voltage (e.g. above 40V) being present for long enough time at DUT VBATT input that can damage components.

The solution is to run CI 210 per FMC1278 that has corrected the test procedure: at each test frequency adjust and record the signal generator output required to achieve the specified modulation voltage level “Us” with the DUT disconnected (open circuit).


Christin Rosu
Loading