New Concept for Higher Speed on Existing Catenary System: Auxiliary Pantograph Operation

Transcription

1 New Concept for Higher Speed on Existing Catenary System: Auxiliary Pantograph Operation Zhendong Liu, Sebastian Stichel, Per-Anders Jönsson KTH Royal Institute of Technology, Sweden Anders Rønnquist NTNU Norwegian University of Science and Technology, Norway

2 BACKGROUND

3 Background Reasons for contact force variation and high dynamic load: Stiffness variation in a span Wave propagation High dynamic load in the contact between pantograph and catenary: Low quality of current collection Excessive mechanical wear Electromagnetic interferences Even structural damage

4 Background Complicated system & deterioration trend Solutions for higher speed Low stiffness variation High tensile force Damping or pre-sag High-speed pantograph Actively-controlled pantograph Table 4.1: Tensile force applied to high-speed catenary systems [46] Country System Operational speed Tensile force on contact wire Tensile force on catenary wire Sweden SYT 15/ kn 15 kn Germany Re kn 21 kn France Atlantique kn 14 kn Italy Rom-Neapel kn kn Spain Madrid-Lerida kn kn Japan* Osaka-Hakata kn 24.5 kn China Beijing-Shanghai kn 20 kn * Compound catenary system: the tensile force on the auxiliary wire is 14.7 kn. Strength limit of material in the future Long out-of-service time & Huge investment

5 Background Demand - Easy to implement on the existing pantographcatenary system. - Short out-of-service time and low investment. - Not limited by material strength. One possible solution for higher speed Auxiliary Pantograph Operation A pantograph is designated to create a favourable working condition for the main working pantograph.

6 SIMULATION TOOL

7 Simulation tool Simulation based on the finite element program ANSYS and a 3D pantograph-catenary model Side view: Catenary wire Stitch wire Steady arm Dropper Contact wire Top view: Contact element L x Lateral stagger Contact wire Steady arm Track centre line k 1 m 1 c 1 c 3 d 1 m 3 m 2 c 2 m 4 d 2 kf 3 f 3 k 2 Contact strip perpendicular to running direction to show lateral stagger Droppers insulating the axial compression force to express dropper slackening

8 Simulation tool Description of system parameters: Schunk WBL88 pantograph In the following part, the standard deviation is regarded as a key indicator to evaluate the quality of pantographcatenary interaction.

9 BENEFICAL EFFECT

10 Beneficial effect Two-pantograph operation at short spacing: Investigation Pantograph: WBL 88 Catenary: SYT 7.0/9.8 Running speed: 200 km/h Speed: km/h Spacing: m Leading Trailing The meshed area marks the cases where the leading or trailing pantograph works even better than in single pantograph operation at 200 km/h What can cause this?

11 Contact force (N) Standard deviation (N) Proper excitation Leaading Trailing Single Spacing distance (m) Two-pantograph vs Single-pantograph 80 Beneficial effect Leading 60 Trailing 0.6 At 40 m Stiffness Longitudinal location (m) 1 Vertical stiffness (N/mm) Vertical displacement (m) Meeting a downwards-moving catenary to acquire additional compressive force where the contact is soft A B C D E Point A (-4.5 m) Point B (0 m) Point C (+4.5 m) Point D (+9 m) Point E (+13.5 m) Possible place to introduce an additional trailing pantograph Distance after pantograph passing-by (m)

12 Beneficial effect Wave interference Amplitude (N) Frequency analysis of contact force Single-pantograph Trailing - Spaced at 40 m Amplitude (N) Trailing - Spaced at 60 m Single-pantograph Magnitude of wave (cm) Time (s) Two oscillating sources at nearly the same frequency 0 Wave 1 2 Frequency 4 (Hz) Wave 2 Resultant wave Vertical displacement (m) f p = 1 = v L=0.93 Hz T p 40 m Propagating wave interference Wave propagating speed C Longitudinal location (m) Frequency (Hz) f c = α f p = Wave Interference c c v f p=1.86 Hz What can change this frequency?

13 Auxiliary pantograph operation Leading Overcome electrical wear by no electric load Electric load + Arcing Wear Soft contact Overcome mechanical wear by low uplift force 20 Trailing Standard deviation (N) Trailing pantograph Single pantograph at 200 km/h Single at 200 km/h V.S. Trailing at 260 km/h Percentage of the normal contact force applied (%) Uplift force reduction of the leading pantograph can improve the dynamic performance and reduce the mechanical wear. Normal two-pantograph operation at high speeds Contact force (N) Longitudinal location (m) Single Leading - normal Trailing - normal Leading - reduced Trailing - reduced Leading panto. as auxiliary panto. serves the trailing panto.

14 IMPLEMENTATION

15 Implementation Auxiliary pantograph operation Switch it off from Circuit Using two pantographs together & Taking one of the pantographs as auxiliary pantograph. Similar application Bulbous bow Increasing speed Reducing fuel-consumption Enhancing stability Big front nose

16 Variable Spacing distance 40 m Tension force 7 kn, 9.8 kn Uplift force N Damping ratio 0.02 Mass of panhead 6.6 kg Stiffness of pan-head 4400 N/m Sensitivity investigation 5% deviation of some key parameters (a). Ratio of deviation Result of the trailing pantograph Mean contact force (N) Standard deviation (N) Percentag e -5% % +5% % -5% % +5% % -5% % +5% % -5% % +5% (b) -0.1% -5% % +5% % -5% % +5% % Normal value Vertical displacement (m) Low damping Leading Trailing Longitudinal location (m) The contact forces with low damping ratio of 0.5% and 5% at 260 km/h. Vertical displacement (m) High damping Leading Trailing Longitudinal location (m) The system is not very sensitive to parameter deviation.

17 Contact force (N) Contact force (N) Emergency and Special section Pantograph raising and lowering: Train passing through special sections Emergency condition. i.e. obstacle on catenary Other unfavourable working conditions m Time (s) m 40 m Auxilary Trailing 60 m Auxilary Trailing Time (s) Spacing distance is important & improvement is seen. At certain speed the auxiliary pantograph can smoothly get into force. Contact force (N) Contact force (N) middle 6 v Time (s) Auxilary At 200 km/h Trailing At 260 km/h Auxilary Trailing middle Time (s)

18 CONCLUSIONS

19 Conclusions Taking one of pantographs on trainset as auxiliary pantograph is a feasible solution for speed-increase on existing railway system. Poor dynamic performance and excessive wear can be avoided by reduction of uplift force. The system is not very sensitive to small parameter deviations. Unfavorable working conditions can be avoided by pantograph raising and lowering operation.

20 Future work Investigations of the relationship between the response of the catenary after pantograph passing-by and some other parameters Further parametric studies taking into account factors such as disturbances, structural errors and special sections A better understanding can help to find more technical solutions.

21 Thank for your attention Time for question and suggestion Zhendong Liu