Power supply system of indian railway coaches railelectrica electricity bill nye


Two power cars each equipped with 2×750 kVA DG sets, one at each end of the train, supplies 3 phase power at 750 V AC power to each electrically interconnected air conditioned coach. The voltage is stepped down to 3 phase 400 V and supplied to standard voltage equipment on each coach. EOG system is followed for fully air conditioned train like Rajdhani, Shatabdi, Duranto, Garib Rath, Premium special trains. Import of LHB class of coaches from Germany is provided with the EOG system with a promise to provide SG system design for indigenous manufacturing. SG technology given was a complete failure and IR is still struggling to develop designs for the last 15 years. Head-on-Generation (HOG)

Power is supplied from the train locomotive at the head of the train. The single phase 25 kV transformer of the electric locomotive is provided with hotel load winding which is converted to three phase AC at 750 V using 2×500 kVA inverter and supplied to the same system as that of EOG. In case of Diesel Locomotive, three phase alternator is mounted on the traction alternator and feeds the hotel load. This is the most efficient system as the cost of power is about 25% less as compared to EOG, but the system is still under development for the last 30 years. electricity transmission loss The other class of trains namely Electrical Multiple Unit and Main Line Electrical Multiple Units employs the same system for coach lighting. The system is similar to what is followed in train-set composition of train having a power unit at head as well as on tail and power the entire load of the coach for comfort. Running of mixed LHB design AC and non-AC coach

There is a need for running a mix of AC and non-AC coaches with LHB coach design to improve passenger satisfactory, higher capacity and improved riding with less maintenance. RCF has already started manufacturing Non-AC LHB and 276 such coaches have gone into service till 31 st March 2014 and working on Northern Railway, North Western Railway, Western Railway, East Central Railway and Eastern Railway. The only way to power these coaches is by EOG system as the SG design not yet successful. The electrical load of the train is about 250 kW and with a diversity factory of 80%, system loading will be around 200 kW for which the existing power cars is of over capacity. Development history of SG AC LHB coach

In this arrangement, 25KW alternator was of conventional type except belt transmission replaced with a cardon shaft which was driven by a gear box mounted on the axle. The alternator was mounted on the coach underframe to take care of space constraints in the bogie. electricity prices per kwh 2013 This design was given by LHB to RCF as per the contractual condition. Based on this design, one rake was turned out to work in Shalimar rake (4545/4646). The rake turned out by RCF worked between NDLS & JAT for few days but design lapses surfaced out within a short period. The design lapse was non-damping of vibrations emerging from the track irregularities resulting failure on account of breakage of gear box & Cardon shaft, failures of fasteners provided for coupling of Cardon & gear box, shearing of flange for coupling, jamming of Cardon shaft arrangement, development of gap between torque limiter plates, breakage of gear box torque arm pin cap locking stud in Cardon shaft system and damage of fork arm bolt provided in Cardon shaft arrangement. Failure Mode of Cardon Shaft arrangement

These type of alternators were developed by M/s Landert HMTD, Mumbai and 4 nos. of alternators with ERRUs were commissioned successfully on LHB SG ACCN coach nos. 05143 & 05146 and put on 06 to 08 months commercial trial in Shalimar Rake (4545/4646) ex. NDLS to JAT and with a lot of problems when put into service. Finally, the coaches were detached from the Shalimar Rake and sent back to RCF by Northern Railway. electricity and magnetism worksheets 4th grade The defects observed were damage of bearings, grease leakage, damage/burning of stator windings & insulating material, breakage of terminal box, accumulation of copper dust and repeated control card failures in ERRU etc. Apart from above, M/s. Landert, Switzerland, who was the technical partner of M/s. HMTD, Mumbai did not technically supported M/s. HMTD. The most important issue of the design was that if the bearing fails, it results in immobilization of the coach, most severe condition of service failure and project failed. Belt Driven Permanent Magnet Alternator

The existing Alternator used in conventional SG AC coaches cannot be fitted in the LHB-FIAT bogies due to space constraint in FIAT bogies. At this stage, Indian Railway was in look out for a smaller size alternator which can be fitted within the space available. It was well-known that the size reduces considerably with the use of a permanent magnet alternator and that gave the lead. wd gaster x reader Two numbers of belt driven 30 kW alternators with permanent magnet were developed and installed on a coach for trial. This design has been developed in close coördination of RCF, RDSO and M/s I.C.Electricals. This coach has been running in regular service since Nov. 2012 with satisfactory performance. The advantage with permanent magnet is due to reduction in the size of the rotor as it does not have winding to generate electric field, and therefore, a reduction in overall size, weight, efficiency, durability and you name the advantage, it is there. But the progress is slow for two reasons

• HOG system is considered to be the most economical for the reason the cost of generation is minimum, but the issue is that the head on locomotive is not wedded to the train. If for some reason, it is detached, there is no source of power, therefore, one power car has to remain in the system. There is one more angle to this, that if the power car become mechanically sick en route and detached then continuation of both the power cars justified even with HOG. This is the reason that there is not much enthusiasm for HOG.

• There is always debate about the economics of SG versus EOG and each group justifying in his own way. EOG favours all factors over SG, except two i.e. the earning capacity of the power car and loosing flexibility of interchangeability . For this, the initiative was taken to develop under slung mounted DG set, thus releasing the space for luggage. If this is done, all economics will shift towards to EOG system. As regards, flexibility of interchangeability, successful running of LHB coach train mix with AC and Non-AC on EOG has proved this wrong and is only a fear.

• The most important financial, practical and workable solution is to develop under slung mounted DG sets in two versions of 2×750 kW and 2×250 kW for fully AC and mix train of AC and non-AC coach . astrid y gaston lima menu english This will release 50% of the space presently used in the power car for DG set and power panels. The design of the power panel shall be so chosen to have the flexibility to draw power from HOG as well. The cost of electric energy through HOG will be much less as compared to EOG.

Capital and Maintenance Cost: The capital and maintenance cost of a large number of under slung mounted equipment such as alternator, pulley, belt, Electronic regulator, battery and invertor will get a go bye with the addition of maintenance cost of four numbers of DG sets and their panel. It is the total quantity of these items in SG coaches that makes the difference in all aspects of reliability and maintainability.

1. SG system is widely followed where in each coach is capable of working as one unit independent of rest of the train. An alternator is attached to the wheel and the output rectified to charge a battery at 110 V DC. This stored power is utilized directly to light and fans in sleeper coaches and through a three phase inverter to AC coaches. The sytem is energy inefficient, large number of components, maintenance and theft issues.

2. electricity storage association EOG system is widely used in Rajdhani, Shatabadi, Duronto, Garib Rath type of trains having inter coach connectivity in which a Power car equipped with DG sets in connected at each end. There are two DG sets in each Power car with 100% redundancy. The power is stepped up to 750 V 3 phase AC and distributed to each coach where it is transferred to 415 V 3 phase AC and distributed to coach for different applications. The disadvantage is that the coach is married to the train and can only be changed with the same type of coach. It requires additional manpower for power car manning etc.

3. HOG system. IR is working for Head On generation for the last 35 years but could not be implemented due to many constraints. EMU/MEMU type trains are basically with HOG type of system. The new series of passenger locos WAP7 is equipped with additional winding for hotel load along with an inverter to supply constant frequency supply. This power is taken to the adjacent coach and transferred to the train through a change over switch. The challenge is that only one power car can be replaced and one has to be kept to supply power during failure of the locomotive or immobilisation of one of the power car. This arrangement give significant saving in diesel oil. IR is looking how to make use of part of the power capacity for carrying passengers. HOG is the future and IR is working accordingly.

A train hauled by electric locomotive draws its power in India from 25 kV single phase Overhead wire and same is converted into low voltage in the range of 1500-1000 V single. There are two types of locomotive plying in India, one provided with DC Series motor and another three phase asynchronous motor. wd gaster cosplay Locos provided with DC series motor are fitting with rectifier and a online tap changer whereas the other one provided with line converter and inveter to feed VVVF control of three phase motor.

1. SG i.e Self Generating System in which a alternator is mounted underneath the coach which draws it mechanical power from the energy of the train and converts into 140 V AC, which is rectified and charges to a battery and battery supplies all the load. For air conditioning, a three phase inverter of 25 kV capacity is provided to feed roof mounted package AC unit. This system has the disadvantage of poor energy efficiency but flexibility and can be attached to any train.

2. EOG i.e. gas variables pogil answers End on Generation: This system has a generator van at both end provided with two numbers of DG sets of adequate capacity to feed the entire load of the train. The need of the system is important for fully air conditioned trains due to higher requirement of load. Rajdhani, Shatabadi, Duronta, Garib Rath type of trains are all provided with this system. The sleeper coach version of LHB coach has the limitation of difficulty of mounted underslung alternator and therefore, such trains are provided with end on generation. Except the flexibility, such trains has many advantages.

3. HOG i.e Head on generation: In this system instead of providing Generator van at both ends, the power is tapped from the main transformer of the locomotive and 2 nos. of 500 kVA inverter are installed in the locomotive or generator van and power supply fed to the system. The problem with the system is that if the locomotive fails, detached, or when the train is waiting for engine to be attached the train will be dark. Hence, only one power car can be dispensed with. The Electrical Multiple Unit trains running over sub-urban network called local trains are the example where the power drawn from the OHE is used for lighting and fannage of the coach. All over world, they are shifting to train sets instead loco hauled trains. In a train set there are two-three powered coach similar to metro trains and thus reliability of ensuring power supply to coach is fully ensured.