28-02-2013, 09:09 AM
POWER SUPPLY IN A/C COACHES IN INDIAN RAILWAYS AND ABOUT LHB COACHES
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POWER SUPPLY IN A/C COACHES
The power supply technology used in train interiors have indirect coupling with axle.
This makes system lesser efficient and bulky.
Magnets mounted on axles with stator of slotted hollow cylinder will make alternator that will be robust and light weight. This cheaper system will be simple and easy to use.
The output voltage from alternator will have many frequencies .Hence we will pass it through converter cum regulator insuring total elimination of harmonics .
The pure DC output from it will be feed to batteries and supply.
AUTOMATIC FEEDBACK CONTROL SYSTEM
It is a feedback system because rotational energy is output of train while it is input for alternator and output of alternator, electricity is again transferred to power supply system of train.
The production of electricity from this system is also at the time of breaking.
Trains have very fluctuating speed hence this electricity produced will also be fluctuating in nature so we cannot feed this to supply directly.
APFC
The controller continuously senses the instantaneous magnitude and direction of the reactive power demand through line Current Transformer (CT) and Potential Transformer (PT).
It generates a signal for switching and turns the capacitor bank on & off to provide the necessary reactive power (kVAr). This achieves the pre-determined value of Power Factor (PF).
OBJECTIVE
To make power supply system for trains with betterment in scales of efficiency, cost, safety,weight,simplicity and reliability.
Generally trains have 400-1500 rpm in normal speed. If we cover the axle by hollow cylinder with conductor slots and rotor mounted with permanentmagnets then this will make a alternator.
A thin layer of insulation is provided to axle from
rotor for high quality safety purpose. Holders confirm the connectivity of magnets and axle.
ABOUT LHB COACHES
The Linke Holfmann Busch (LHB) coaches are the passenger compartments of Indian Railways that have been developed by Linke-Hofmann-Busch of Germany (taken over by Alstom in 1998) and produced by Rail Coach Factory in Kapurthala, India.
They are used since 2000 on the Indian Broad Gauge (1676 mm) network of Indian railways. Initially, 24 air conditioned coaches were imported from Germany that would be used for the Shatabdi Expresses, after which the Rail Coach Factory started manufacturing after technology tranfer.
CONCLUSION
Hence we will be able to not only reduce mechanical complexities but also cost and weight of power supply system will be also drastically drop.
With all this trains can come with super efficiency power supply system.