1 Introduction
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Freight wagons,
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Mass transit,
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Passenger coaches,
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Locomotives, and
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High-speed trains.
2 The test case: the EMU V250 train
Coach | Bogie | Wheel diameter (new) (mm) | Wheel diameter (worn) (mm) | Brake radius (mm) | Number of disks/axle | Dynamic pad friction level | Brake actuator piston surface (cm2) | Spring counter force/actuator (N) | Caliper efficiency | Ratio of the caliper |
---|---|---|---|---|---|---|---|---|---|---|
M1 | 1 | 920 | 850 | 299 | 2 | 0.42 | 506,7 | 1,300 | 0.95 | 2.82 |
2 | 920 | 850 | 299 | 2 | 0.42 | 506,7 | 1,300 | 0.95 | 2.82 | |
T2 | 3 | 920 | 850 | 243 | 3 | 0.42 | 506,7 | 1,300 | 0.95 | 2.69 |
4 | 920 | 850 | 243 | 3 | 0.42 | 506,7 | 1,300 | 0.95 | 2.69 | |
M3 | 5 | 920 | 850 | 299 | 2 | 0.42 | 506,7 | 1,300 | 0.95 | 2.82 |
6 | 920 | 850 | 299 | 2 | 0.42 | 506,7 | 1,300 | 0.95 | 2.82 | |
T4 | 7 | 920 | 850 | 243 | 3 | 0.42 | 506,7 | 1,300 | 0.95 | 2.69 |
8 | 920 | 850 | 243 | 3 | 0.42 | 506,7 | 1,300 | 0.95 | 2.69 | |
T5 | 9 | 920 | 850 | 243 | 3 | 0.42 | 506,7 | 1,300 | 0.95 | 2.69 |
10 | 920 | 850 | 243 | 3 | 0.42 | 506,7 | 1,300 | 0.95 | 2.69 | |
M6 | 11 | 920 | 850 | 299 | 2 | 0.42 | 506,7 | 1,300 | 0.95 | 2.82 |
12 | 920 | 850 | 299 | 2 | 0.42 | 506,7 | 1,300 | 0.95 | 2.82 | |
T7 | 13 | 920 | 850 | 243 | 3 | 0.42 | 506,7 | 1,300 | 0.95 | 2.69 |
14 | 920 | 850 | 243 | 3 | 0.42 | 506,7 | 1,300 | 0.95 | 2.69 | |
M8 | 15 | 920 | 850 | 299 | 2 | 0.42 | 506,7 | 1,300 | 0.95 | 2.82 |
16 | 920 | 850 | 299 | 2 | 0.42 | 506,7 | 1,300 | 0.95 | 2.82 |
Coach | Bogie | VOM load (Tare) (t) | TSI load (t) | CN load (normal) (t) | CE load (exceptional) (t) | Bogie mass (t) | Rotating mass/axle (t) |
---|---|---|---|---|---|---|---|
M1 | 1 | 15.9 | 16.7 | 17 | 17.6 | 9.93 | 1.5 |
2 | 13.9 | 15 | 15.4 | 16.3 | 9.81 | 1.5 | |
T2 | 3 | 13.9 | 15 | 15.3 | 16.6 | 7.85 | 0.6 |
4 | 14 | 15.1 | 15.4 | 16.5 | 7.85 | 0.6 | |
M3 | 5 | 13.6 | 14,8 | 15.2 | 16.1 | 9.81 | 1.5 |
6 | 14.1 | 15.5 | 15.9 | 16.8 | 9.81 | 1.5 | |
T4 | 7 | 11.2 | 12.8 | 13.3 | 14.2 | 7.85 | 0.6 |
8 | 12.1 | 13.7 | 14.2 | 15 | 7.85 | 0.6 | |
T5 | 9 | 12 | 13.6 | 14.1 | 14.9 | 7.85 | 0.6 |
10 | 11.3 | 12.8 | 13.2 | 14.1 | 7.85 | 0.6 | |
M6 | 11 | 14.1 | 15.7 | 16.2 | 17 | 9.81 | 1.5 |
12 | 13.8 | 15.3 | 15.8 | 16.7 | 9.81 | 1.5 | |
T7 | 13 | 14 | 15.6 | 16.1 | 16.9 | 7.85 | 0.6 |
14 | 14.1 | 15.6 | 16.1 | 17 | 7.85 | 0.6 | |
M8 | 15 | 13.7 | 15.2 | 15.7 | 16.5 | 9.81 | 1.5 |
16 | 15.9 | 16.9 | 17.2 | 17.8 | 9.93 | 1.5 | |
Train mass (t) | 435.2 | 478.6 | 492.2 | 520 | |||
Train rotating mass (t) | 33.6 |
2.1 Further controls: double pressure stage and load sensing
2.2 Electrical braking and blending
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Maximum pneumatic braking force: under a certain traveling speed, the corresponding operating frequencies of the traction system are too low. On the other hand, also the demanded braking power is quite low, and so it can be completely managed by means of the pneumatic braking system.
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Minimum pneumatic braking: in this region, the electric braking effort is limited to a maximum value, often related to the motor currents. If a higher braking effort is required, then the pneumatic brake is activated to supply the difference.
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Pneumatic braking increases to supply insufficient electric power: as speed increases, the performances of the motor drive system are insufficient to manage the corresponding power requirements, limiting the maximum braking effort to the associated iso-power curve. As a consequence, the contribution of the pneumatic braking power tends to increase with speed.
3 Summary of the European standards for brake calculation
4 Software—TTBS01
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Pre-processing (Import DATA): the train and simulation data are input by user.
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Configuration (Config.): data are saved and stored in files.
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Post-processing: the user can view the representative brake output in several charts.
5 Tool validation
Pressure transducer | Radar Doppler sensor | Servo-acelerometer | Thermocouples | |
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Accuracy | 0.5 % respect to full range | ±1 km/h | 0.1 % respect to full range | K type thermocouples |
Range | 0–12 bar | 0–500 km/h | 1 g | |
Quantity and layout | 8 pressure transducer on brake plant | 1/on a coach carbody | 1/on a coach carbody | 4/on disks |
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VOM load condition, defined as mass empty, ready for departure;
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TSI load condition, corresponding to mass normal load; and
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CE load condition, defined as mass exceptional load.
5.1 Acceptance criteria
Probability (no. of tests) | 10−1 (101) | 10−2 (102) | 10−3 (103) | 10−4 (104) | 10−5 (105) |
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Mean deceleration | 0.969 | 0.945 | 0.926 | 0.905 | 0.849 |
Nominal deceleration | (−3.1 %) | (−5.5 %) | (−7.4 %) | (−9.5 %) | (−15.1 %) |
Compostion | First eigenfrequency | Second eigenfrequency | Third eigenfrequency | Fourth eigenfrequency | Fifth eigenfrequency |
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Standard (8 coaches) | 2.4 | 4.7 | 6.9 | 6.9 | 8.8 |
Doubled (16 coaches) | 1.2 | 2.4 | 3.6 | 4.8 | 5.9 |