The document discusses an investigation into resolving radiated emission (RE) issues on an Innovia vehicle to comply with CENELEC standards. Measurements found a 105kHz resonance from the vehicle that exceeded limits. The root cause was identified as parasitic capacitance between inverter components coupling high frequency harmonics into power rails and causing line resonance. Modifications like adding shunting capacitors and common mode chokes to both propulsion and auxiliary inverters were able to block and contain harmonics, eliminating line resonance and bringing the vehicle into compliance.

1. PRIVATEANDCONFIDENTIAL
©BombardierInc.oritssubsidiaries.Allrightsreserved.
Innovia Vehicle
Radiated EMI
Investigation
and CENELEC
Compliance
Solution
Systems Engineering
Group
Jian Shen May, 2016

2. Innovia Vehicle Radiated EMI
issue---History
• Independent consultant
test Lab TUV came to
measure and found the
test vehicle was not RE
CENELEC compliant;
• The measurement
showed a 105kHz
resonance;
• Identified Radiated
Emission source being
from the vehicle.

3. Allowed limits (EN50121-3-1)

4. Comparison of existing reality and
standard to be met
Standard to be met

5. Typical Propulsion/Aux Inverter EMI
Filter Design Considerations
• Customer specification limits;
 For steady state harmonics
• Traction motor impedance;
• Supply voltage;
• Inverter switching frequency;
• PWM schemes used etc.;
 For transient harmonics, impulse
emissions etc.
• Charging up speed (resistor, load
shed etc);
• Line switch control strategy;
 Combined consideration with
system stability
Input filter design considerations focus on the Conducted Emission side

6. 6
A typical example of equipment EMI filter design
--- using FDM take a whole cycle of acc. - coast - dec. run @ AW3 and sum the spectra together

7. Filter parameters’ theoretical attenuation
did not match reality in this case
10
1
10
2
10
3
10
4
10
5
-160
-140
-120
-100
-80
-60
-40
-20
0
20
frequency (Hz)
gain(dB)
Lf=4.4mH
Lf=1.1 mH
Innovia aux inverter input filter with Lf = 4.3mH and Cf = 0.88mF, 9/28/06

8. The stray capacitance (blue) effect and the common mode
filter (pink)---50uH/ferrite rings, 2*2uF shunting capacitor

9. Innovia test track model

10. http://en.wikipedia.org/wiki/Transmission_lines
A common rule of thumb is that the
cable or wire should be treated as a
transmission line if the length is
greater than 1/100 of the
wavelength”.

11. Section of drawing --- Innovia aux inverter with added CM filter
C1
C2

12. Low Cost Common Mode Filter, 50uH, 2*2uF

13. Implementation of the common
mode filter in the aux. inv. box

14. Test set up

15. Comparison of background noise and
without filter in aux inverter (stationary)

16. Comparison of background noise and with
filter in aux inverter (stationary)

17. Propulsion inverter effect with no filter

18. Implementation of shunting capacitor in Prop. and
Aux inverters

19. Both prop. And Aux. Inverters with shunting
capacitors

20. 20
Innovia Vehicle and CITYFLO 650 CBTC – London Heathrow
Terminal 5, UK
CITYFLO is a trademark of Bombardier Inc. or its subsidiaries.

21. 21
Innovia Vehicle and CITYFLO 650 CBTC – Dallas Forth
Worth, USA
CITYFLO is a trademark of Bombardier Inc. or its subsidiaries.

22. 22
Guangzhou ZJXC Fully Automated System with CITYFLO 650 CBTC
N
 Awarded 2007
 Scope
– 4 km dual guideways (in tunnel)
– 9 passenger stations
– 14 CX-100 vehicles
– 10028 pphpd (required)
– 100 seconds Hdwy (required)
– 2 turntable and 16 pivot switches
– 1 ATC region
– Automated storage yard
 Revenue Service before October 2010
Asia Games.

23. Conclusions
1). The parasitic capacitance between both the propulsion and auxiliary
inverter’s IGBTs and heatsink are the main root cause of high
frequency harmonics being coupled into the power rails and causing
line resonance.
2). The DC power rails can not be simply treated as DC bus bars when
considering the frequency range higher than 10kHz, transmission
line theory should be applied.
3). By utilizing the shunting capacitors and the common mode choke,
the high frequency harmonics are effectively blocked and shunted
within the inverters themselves. This eliminated the line resonance
caused by both the auxiliary and propulsion inverters.
4). The cost/effective measure has been tested in many cases and
proven to be effective.