Join me as we discuss various railway engineering topics with examples. We have tried to use basic math & physics to derive various standard formulas available in IECs, IEEEs and ENs. These lectures will support you in understanding electrical concepts behind railway engineering and make you love your work more than ever.
Information provided in my videos is for educational purpose only.
Hello. Your video is so helpful. By the way, at 9:36 the third formula named EN50522 is different from the drived formula. Could you explain why the third one is different from the first?
Actually, all these standards not only follow the derived expression, but make suitable adjustments to it based on test reports and results from software to match accuracy. Therefore, you might some changes. However, the approach remains same.
Yes it helps and rolling sphere shall be applied. Please note that in this case you need check equipment that are roof mounted and be careful with the design.
Just waaaw ! Sir, if you feel free then please help me with the answer of my confusion. 1. What is the technical reasons behind the use of catenary wire, as the pantograph touches with only contact wire. That reason is so important that Railway expends money on using 2 wires contact wire & catenary wire both. 2. What is the reason behind the use of false catenary wire under ROB, FOB Please sir clear my doubts
AEC and BEC are required for multiple reasons. Some of them are listed below 1. Cross bonding and other measures are not sufficient to reduce rail potential so that it falls within the limit. 2. To ground OCS poles and Wayside equipment with every time drilling or cadwelding with rails. 3. AEC also helps in reducing EMI. Running rails along with AEC and BEC form the part of return circuit. You can avoid them completely by increasing cross bonding between tracks, design for headway mentioned in contract and not overdesign, evaluate rail potential as per annex C provided in EN 50122-1, providing earth pits along the route. All this require detailed analysis.
Sir, why can't we centre tapped the secondary of Scott connected transformer as we are doing for V-connected transformer? Why we have to use Auto Transformer after Scott connected transformer?
Current flows in the form of charges within the earth surface. Earth is full of charges that support it. The main concept here is that the circuit has to be completed in order for the current to flow, and that happens through earth and other return conductors in case of fault.
Sir, how to calculate zero sequence impedance of power cables (R0/R1, X0/X1) in Indian standard the ratio of R0/R and X0/X is mentioned for a problem that the values are taken from manufacturer data sheet but when checked cable data sheet doesn't contain this ratio. Also in IEC60909-2 it is not clearly defined. Pls explain with an example
Sir didn't answer so I will. Calculating zero sequence impedance of a 3 phase power cable is unreliable. If you don't have manufacturer's data, and don't want to estimate, it's better to measure it
Dear DR.Sahil thanks for a wonderful video co-relating with corona precautions.... plz share more videos about ur know how to educate us... waiting for ur upcoming videos on this topic. Thanks 😊
Very important topic, looking forward to this. If EMC isn't looked after from early in the railway project, it can get quite expensive to resolve later on!
Absolutely! If neglected at the start it becomes quite expensive later on and involves a lot of rework in some cases. Will try to upload some more videos with case studies.
Thanks. Yes, it is infact very simple with autocad, however, many don't have ready access with them so manual calculations become helpful in that case.
Thank you for the video! This applies only for the loads/facility that has its own transformer on LV side? Because you have a direct grounding connection from the load to the transformer? If you would have a more distributed load, by that i mean that the load is more distant from the transformer station, the ground faults would be (depends on the earthing/supply TN or IT or TT) through ground or neutral conductor?
Yes, you are correct. It is only in case the TN system is adopted. As in new metro projects that have limited areas, the TN-S scheme is mostly preferred. In case of TT system, we need to evaluate both sides HV and LV line to ground faults and chose the worst case.
It depends on reference angle which you have considered. In this 54 deg is considered so we can consider BC as perpendicular and AB as base. If your angle is /_ACB then AB is perpendicular and BC base.
