Channel Title: Railway Engineering Insights Channel Description: 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. Cheers! Sahil Bhagat https://www.linkedin.com/in/sahil-bhagat-0440b439/ Email ID: railwayengineering2020@gmail.com <video> Lecture 10: Wayside Earthing & Bonding - TT and TN-S System Description: This video provides an understanding of the design of LV power system earthing arrangements (TT and TN-S system). It provides insights into the bonding requirements for LV powered wayside equipment for a.c. railway based on EN 50122-1. </video> <video> Stray Current Lecture 1: Basics of Stray Current in DC Traction Description: This video captures the basic understanding of stray current in DC traction system and provides an explanation using basic electrochemistry. It describes the important parameters that are the root cause for stray current with the help of basic electric model. </video> <video> Lecture 12: Earth Resistance Test - Part 2 Description: This video provides the connection diagram required to conduct the test using fluke 1625-2. It provides a detailed explanation of probe spacing {09:00}. It explains the different types of interferences that might occur during the test {16:15}. Furthermore, it provides the derivation of why the magical number 62% is used while conducting the earth resistance test {19:42}. </video> <video> Lecture 4: Stray Current Collection System Description: This video provides an overview of Stray Current Collection System (SCCS) and covers the design aspects based on EN 50122-2. It explains the two (2) types of SCCS (Floating and Earthed) used in metros. Furthermore, it provides the methodology for sizing of dedicated stray current collection rebars and dedicated earth rebars in track slab & pier structure based in EN 50122-2 and IEC 62305-3. </video> <video> Fault Analysis Lecture 5: Reduction or Split Factor for LG fault Distribution Description: This video captures one of the most important parameter responsible for sizing of earth system, i.e., the earth current. Reduction factor or split factor provides the actual value of earth current leaving the earth system and going back to source. This part of fault current is mainly responsible for the surface potential distribution (touch & step potentials). This video details the formulas based on EN 50522, IEC 60909-2/3 & IEEE 80 and provides their derivation. Along with this it captures formulas & derivations for the zero sequence impedance for cable sheath and impedance of static earth wire & tower resistance in case of OHL. </video> <video> Lecture 3: Design Provisions to Reduce Stray Current & Overview of Platform Insulation Membrane Description: This video captures the design provisions to reduce the stray current in DC traction system as per EN 50122-2. It provides detailed explanation for keeping the return circuit floating rather then earthed. Along with this it provides basic understanding about the requirement of platform insulation membrane as per IEC 60364-4-41. </video> <video> Lecture 9: Wayside Earthing & Bonding - Overhead Contact Line Zone (OCLZ) & Current Collector Zone Description: This video describes the protective provisions for exposed conductive parts and wholly or partly conductive structures within Overhead Contact Line Zone (OCLZ) & Current Collector Zone (CCZ) as prescribed in EN 50122-1. It explains the basics behind such protective provisions through simplified electrical circuits and lays the foundation for earthing and bonding provisions for wayside equipment (SIG, COM, MEP, Traction, etc.) and civil structures. </video> <video> External Lightning Protection System Lecture 1: Basics of Air Termination System Description: This lecture provides a basic understanding of the air termination system as per IEC 62305-3(external LPS design). It provides an overview of the rolling sphere method (RSM) and protection angle method. Furthermore, it explains how the protection angle method is a mathematical simplification of RSM and provides what angles are to be considered for different heights of rods and class of LPS. It explains that 45 degrees of protection angle that we consider is not in accordance with IEC 62305-3. </video> <video> Stray Current Lecture 2: Criteria for Stray Current Assessment Description: This video describes the criteria for stray current assessment as per EN50122-2. These criteria help in design of the return circuit, SCCS (Stray Current Collection System) and track design including Fastening System. It defines the most important parameters responsible for stray current in DC traction system as per EN 50122-2. </video> <video> EMC in Railways - Basics Description: This video provides a basic understanding of the concept of EMC in railways. It draws an analogy between EMC and coronavirus, making it very easy to understand. It explains the working principle of standards and briefly explains the EM zoning concept based on the EN 50121 series. For other YouTube videos please refer to this link: https://www.youtube.com/@railwayengineeringinsights6463/playlists </video> <video> External Lightning Protection System Lecture 2: Protection angle method Description: This lecture provides a detailed explanation of the protection angle method based on IEC 62305-3 with examples. Furthermore, it highlights the common mistakes and how to resolve them. It provides the chart provided in IEC 62305-3 and an explanation with examples on how to use it. </video> <video> Earthing & Bonding Lec 8: Misconception of Dedicated Earth Electrodes- Clean, power & lightning rods Description: This video describes the concept behind the use of combined earthing system as prescribed by various IECs & ENs (e.g. IEC 61000-5-2, IEC 60364-4-44, EN 50522, IEC 62305-3). It provides the explanation about why dedicated earthing system (clean, power & lightning earth) is considered as misconception by various international standards. </video> <video> Lecture 11: Earth Resistance Test - Part 1 Description: This video describes the basic understanding of the Earth Resistance Test. It explains the theory behind the fall of potential method (FOP) {1:48} and derives the expression to help understand why it is called FOP {3:23}. Furthermore, it provides the connection diagrams that to conduct the test along with detailed methodology in accordance with IEEE 81 {9:30}. It also provides the rules about probe spacing defined in international standards {14:00}. </video> <video> External Lightning Protection System Lecture 3: Rolling Sphere Method Description: This lecture provides a detailed explanation of the rolling sphere method based on IEC 62305-3 with some examples. It provides the explanation using basic math equations without the requirement of using any software (e.g. AutoCAD). It explains how to calculate penetration depth and explains the common mistakes done using this method. </video> <video> Lecture 6: Understanding 2x25kV ac traction system (Auto Transformer Feeding System) Description: This video provides the basic understanding of 2x25 kV AC traction system (Auto Transformer Feeding System). It explains its advantages (e.g. reduced voltage drop, reduced EMI effect) using basic circuit diagrams. Furthermore, it provides the voltage level required as per EN 50163/EN 50388 and different types of connection techniques such as Scott connected, V-connected/center tapped traction transformers. </video>

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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.

Cheers!
Sahil Bhagat
https://www.linkedin.com/in/sahil-bhagat-0440b439/
Email ID: railwayengineering2020@gmail.com

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