EMC in the railway environment Hans Bängtsson

Transcription

1 EMC in the railway environment Hans Bängtsson

2 Aspects of EMC in the railway environment LEGAL radio-, TV- and tele communications must not be interfered SAFETY The railway signaling ( red and green light ) system must not be interfered FUNCTIONALITY The function of the own control system must not be interfered CO-EXISTANCE Adjacent vehicles on the same track must not interfere each other BIOLOGICAL Passengers and staff must not be exposed to too high magnetic field 2 2

3 EMC Definition The capability of an electric/electronic apparatus or system to operate as intended in its electro-magnetic environment without degradation of performance causing degradation of the performance in other electric/electronic apparatus or system 3 3

4 EU EMC Directive and laws The Electromagnetic Compatibility (EMC) Directive 2004/108/EC Previous EMC Directive 89/336/EEC Swedish EU-direktivet 2004/108/EG and swedish laws EMC-lagen (SFS 1992:1512 och förordningen (SFS 1993:1067) Föreskriften (ELSÄK-FS 2007:1) Important the Guide for the EMC Directive 2004/108/EC (22nd March 2007) The main objective of the Directive is to guarantee free movement of electric/electronic apparatus or system and to create an acceptable electromagnetic environment in the European Community. 4 4

5 EMC standard Trains must fulfil the requirements in the railway EMCstandard EN 50121, divided into six parts EN General EN Emission of the whole railway system to the outside world EN Rolling stock - train and complete vehicle EN Rolling stock - Apparatus onboard the vehicle EN Emission and immunity of the signaling and telecommunications apparatus EN Emission and immunity of fixed power supply installation and apparatus 5 5

6 Other standards IEC almost identical to EN50121 but applicable to the whole world UMTA ICNIRP US Mass Transit Athourity. EMCstandards in USA International Commission for non-ionizing radiation protection for magnetic field impact on the human body 6 6

7 Procedure to achieve EMC 1. Customer specification and applicable standards 2. Calculation of generation of harmonic currents, filter design and selection of modulation strategy 3. Design rules to improve immunity and to minimise EMI and magnetic fields 4. Immunity and emission testing on apparatus or system level in laboratory/test room 5. Final validation of EMI, magnetic fields and harmonic currents by measurements on train 7 7

8 LEGAL Public radio, TV and telephone Emission 8 8

9 Radiated RF-emission regarded from three levels The emission from the apparatus. This test shall be performed in an emission test lab. The emission from the vehicle itself, mainly from its propulsion system. No impact from the pantograph. This test shall be performed with a stationary vehicle or a slow moving vehicle in free field. Slow moving to avoid arcing from the current collector (the pantograph). The emission from the whole railway system, including substation, train and power line (the catenary). The main contribution is probably the emission from the sliding contact between the pantograph and the catenary. This test shall be performed with high vehicle speed in free field 9 9

10 Radiated RF-emission limits for stationary vehicle, i.e. test of the auxiliary system inverter EN stationary vehicle, peak values dbmh,v/m ,001 0,01 0, MHz 25kVAC 15kVAC 3kVDC 1500VDC 750VDC 10 10

11 Radiated RF-emission limits for slow moving vehicle, i.e. test of both auxiliary and traction system inverters EN slow moving vehicle, peak values dbmh,v/m ,001 0,01 0, MHz 25kVAC 15kVAC 3kVDC 1500VDC 750VDC 11 11

12 Radiated RF-emission with moving vehicle limits time to test. The emission are performed in different bands Field Antenna Frequency Bandwidth H-field loop khz 200 Hz H-field loop MHz 10 khz H-field loop 5-30 MHz 10 khz E-field biconical MHz 120 khz E-field biconical MHz 120 khz E-field log-periodic GHz 120 khz 12 12

13 Emission Log-periodic antenna E-field GHz Antenna midpoint 3 m 10 m 13 13

14 Emission test in free field of whole vehicle 14 14

15 Result of radiated emission. H-field 9 khz - 30 MHz Blue Green = background without train = with train 15 15

16 Result of radiated emission. E-field 30 MHz - 1 GHz Blue Green = background without train = with train 16 16

17 Emission test on full size power electronics converter box in the anechoic chamber 17 17

18 Emission-test of smaller units with low power electronics in the anechoic chamber 18 18

19 Functionality Immunity 19 19

20 Immunity test. Our electronics are tested in accordance with standard EN Fast transient burst. Simulates disconnection of inductive loads Surge (high power peak). Simulates lightning Conducted radio frequency. Simulates low frequency radio transmitters (This test is performed conducted due to the long wavelength) Radiated radio frequency. Simulates high frequency radiotransmitters Electro-static discharge Variations and interruptions of voltage supply 20 20

21 Immunity Acceptance criterium. No degradation from the main function, e.g. speed and torque, are supervised Performance criteria A. No degradation of performance. Standard rating and capacity within specified limits. Performance criteria B. Temporary degradation or loss of operability during test, but automatic recovery direct after the test/disturbance 21 21

22 Immunity. Fast transient burst Test set up. Capacitive connection Signal in nonscreened cable Signal in screened cable testsignal External supply EUT Test equipment (burst generator Clamp Distance Earthing braid Protective earth Reference ground plane 22 22

23 Immunity Radiated Radio frequency. Test set up in an anechoic chamber Turn table PC T BC OPTO Fibre T BC 750 VDC POWER SUPPLY DC+/DC- UB+/UB- FWD/REV MCM MITRAC DCU M MVB ISS 110 VDC POWER SUPPLY 400VAC POWER SUPPLY u/v/w/n Speed meas. Motor temp MOTOR Linetrip OPTO Fibre M PC Outside Test hall Test hall Control room 23 23

24 Immunity test with radiated em-field on smaller units in the anechoic chamber 24 24

25 Immunity test with radiated em-field on full size converter box in the anechoic chamber 25 25

26 Safety Signaling system 26 26

27 Singel rail track circuit system. Light traffic. A non-occupied track circuit insulated rail joint green light Receiver Transmitter 27 27

28 Singel rail track circuit system. An occupied track circuit wheel set red light Receiver Transmitter 28 28

29 Right Side Failure A green light accidentally turns to red. Traffic disturbance but not dangerous Traction current red light z Receiver Transmitter z cancelled Traction current 29 29

30 Wrong Side Failure Traction current interferes with track circuit. Dangerous! Traction current with critical frequency green light z Receiver Transmitter z Traction current 30 30

31 Counter measures to avoid impact from frequency content in traction current. Modulation strategy to avoid critical frequencies Line filter to reduce critical frequency amplitude Signal coding E.g. frequency shift between two unique frequencies The risk for wrong side failure can be reduced almost totally, it is only a question of making a more and more complex coding However, when the code becomes more and more complex, the risk for right side failure increases. Traffic problem

32 Biological Magnetic field 32 32

33 ICNIRP Magnetic field recommendation ICNIRP Magnetic field limits versus frequency (ut) ,1 0,01 0, E+08 1E+10 1E+12 (Hz) 33 33

34 Calculation of 16.7Hz magnetfield in a train cab 34

35 Installation principles to reduce emission or to increase immunity 35 35

36 Common mode Differential mode voltage (the real signal) U Common mode voltage V V (interference) 0 V 0 V 36 36

37 Common mode even with short circuit input Differential mode voltage Common mode voltage V V 0 V 0 V 37 37

38 Common mode Differential mode voltage U Common mode voltage 0 V V 0 V 0 V 38 38

39 Filter Supply Equipment Signal The filter time constant shall be as long as the filtered prosess allows! The filter shall reduce signals with frequencies of no interest 39 39

40 Enclosure filter at the border Enclosure LC-filter Apparatus 40 40

41 Zone concept Less sensitive More sensitive Most sensitive Signal 41 Barriers (Filter, screen etc) 41

42 Cable categories A: Disturbing A1 HV-cables A2 Motor cables A3 Auxiliary 3x400 V AC 50Hz B: May disturb, may be sensitive B1 Battery supply B2 Battery control (eg slide protection) B3 Safety cables, magnetic brake C: Sensitive C1 Sensors, loudspeaker, data bus C2 ATC antenna, Microphone, Hearing Aid loop Separation between groups 1-2 dm, within a group < 1 dm. These figures can be reduced if conducting cable ducts are used or screened cables are used 42 42

43 Screened cables shall be grounded at both ends Enclosure Apparatus Screen grounded at both ends Apparatus Low inductance in ground connection Apparatus No pigtails Screen connected 360 deg Capacitor can be an alternative at one end only Grounded in both ends 43 43

44 Parallel Cables routing Capacitive coupling. Cables should normally be separated >5 cm Inductive coupling Cables should normally be separated >10 cm. If this distances are not possible, use metallic cable ducts Cable routed close to metallic structure to increase capacitance to ground 44 44

45 Ground plane, a common source 1 1 & A 1 0 & 0 1 B z i A current i from another source is flowing in the ground plane and through the ground impedance z. Because of z there will be a higher ground potential at B than at A, leading to that the 1 at A s output is interpreted as 0 at B s input. The ground plane impedance must be very low! E.g.The ground plane can be made as a mash, in which the crossings shall be conducting, welded or soldered 45 45

46 Sealed enclosure. Sealed with screws (5 cm) Conducting gasket Leakage gasket 46 46