1
Magnetic Components Used in the Train Pantograph to Reduce the
Arcing Phenomena
Presented by- Saurabh Mishra PESC-140943019
2
contents
Introduction Objective Review of Literatures Research Methodology Detailed description Experimental Model Experimental Results Conclusion References
Introduction
A pantograph always remains in contact with the overhead train line is used to send electricity to the main transformer of the electric train, thus providing power.
Due to many external Disturbances the train line may lose contact with pantograph, causes arcing phenomena to occur.
The arcing produced creates harmonics in the electric over head line and degrades the Power Quality
Physical properties of magnetic components is used improve the contact between the pantograph and the overhead train line
3
4
Objectives
To reduce the arcing caused by contact loss of overhead train line and the pantograph using magnetic components.
To improve the Power Quality in the Over head train line by reducing the current fluctuations.
To optimize the magnetic force based arc prevention methods using Artificial Neural Network.
5
Review of Literatures
It is dangerous to the equipment in locomotives for the over-voltage and harmonic caused by the arcing. Over-voltage amplitude and duration caused by the arcing have been studied (T. Li et al, 2011)
Study of electrical characteristics on pantograph arcing. Arcing Voltages ,currents and their harmonics are analysed. (W. Wang et al, 2011),
6
Research Methodology
Basic Physical Property of magnetic material is used that is “opposite attracts and like repels” by using a Neodymium Magnet.
Simulating a experimental Model and analysing the Results.
ANN Used for Optimisation of magnetic forces required at different time or motor speed.
7
Pantograph
Pantograph is always placed at the top of the train Engine.
Pantograph send electricity to the main transformer of the electric train by making contact with the overhead train line.
A graphite plate is their in pantograph that slides on over head line.
Various Disturbances can cause pantograph rapidly contact and separate with train line results as arcing produced.
8
Lower Arm
Upper Arm
Coupling Rod
Damper System
Collector Head
Slide Plate
Base Frame Fig1: General Description of Pantograph
9
Power system Structure of the Electrified Railway
Fig.2. Single-phase booster transformer (BT) power supply circuit diagram for the Taiwan rail system.
10
Artificial Neural Network
Artificial neural networks are composed of Neurons or processing units.
Artificial Neuron is the basic unit of a Neural network.
Three layered Network input layer, hidden layer and output layer.
Input and output have only layer while the hidden layer may have no layer or multiple layers
A three layered network with feed forward back-propagation algorithm is shown in the figure 5.
11
Fig.3. Feed forward back-propagation network.
Fig 4: Model of the artificial neuron.
12
The formula that relates the input and output in neural networks can generally be expressed using function based on the weighted sum of the input values.
yj=f(ΣWijXi+bj)f : Transfer function, which simulates the non Linear processing function.bj: The partial weighted value of jth neuron simulates the weighted value
of neuron Wij: The weight value of the connection between the ith and jth neuron.
Xj: The input variable for the jth neuron. Yj: The output value of jth neuron, which simulates output signal of
neuron.
13
Experimental Model
An Experimental model is used which resembles the same conductive and motion behaviour as between the train line and the Pantograph.
Ferric disk connected with motor is used, Piece of train line is welded around the ferric disk and touched by electrified graphite rod.
Relative motion between the Ferric Disk and electrified Graphite Rod
gives the same behaviour as between the train line and Pantograph.
Neodymium Magnet is Placed above graphite rod to attract the line that is Welded to the Ferric Disk.
14Fig. 5. Conductive and Motion behaviour between the train line and the pantograph
15
Material Hard-drawn copper
Manufacturing standards UIC870
Outer diameter 12.24mm±0.16mm
Cross-sectional area 107mm² ± 3%
Conductivity ≥97% IACS
Resistivity 0.0175Ω-mm²/m(20 ͦ C)
Thermal expansionCoefficient
17μ/ ͦ C (20 ͦ C)
Elongation 3-7%(200mm)
Destruction Rally ≥3906kgf
Weight 0.95kg/m
TABLE ITRAIN LINE MATERIAL SPECIFICATIONS
16Fig. 6.Forces of contact surface between the train line and the pantograph with eight magnetic blocks.
17Fig. 7. Experiment process for setting the motion between the train line and pantograph.
Set the motor speed
The oscilloscope records current waveform
Add neodymium magnet
Eight magnetic
blocks are joined
Motor speed 1780 rpm
Beginning of the Experiment
The End of the Experiment
NO
YES
NO
18
Experimental ResultsTABLE II: EXPERIMENTAL MEASUREMENTS
OF RMS CURRENT (IN MILLIAMPERES)
19Fig. 8. Comparison chart of speed and load current with/without magnets.
20
TABLE IIINUMBER OF CURRENT FLUCTUATIONS AT DIFFERENT SPEEDS
21Fig. 9. Schematic for iteratively predicting train offline times using neural network algorithms.
Conclusions The contact loss frequency between pantograph and the train
overhead line is reduced.
The measured currents with magnets added is significantly greater than the absence of magnets.
Current fluctuation frequencies are reduced ,decreased collector head current loss thus increases the stability of the power supply system.
The number of pantograph contact losses can be reduced by exploiting the physical properties of magnetic elements.
22
References
W. Wang et al., “Experimental study of electrical characteristics on pantograph arcing,” in Proc. 1st ICEPE-ST, 2011, pp. 602–607.
T. Li et al., “Pantograph arcing’s impact on locomotive equipment's,” in Proc. IEEE 57th Holm Conf. Elect. Contacts, 2011, pp. 1–5.
T. Ding, G. X. Chen, and J. Bu, “Effect of temperature and arc discharge on friction and wear behaviors of carbon strip/copper contact wire in pantograph–catenary systems,” Wear, vol. 271, no. 9/10, pp. 1629–1636, Jul. 2011.
G. Bucca, A. Collina, and R. Manigrasso, “Analysis of electrical interferences related to the current collection quality in pantograph–catenary interaction,” Proc. Inst. Mech. Eng., J. Rail Rapid Transit, vol. 225, no. F5, pp. 483–499, 2011. 23
24
25