Lightning Arresters for Railway System

Lightning Arrester for Traction Systems 1. DC Traction Arrester It is of 10 kA rating. It is designed to be used on the DC voltage systems in the traction applications. Their function is to limit the damaging effects of large lightning derived transient overvoltage conditions. They are suitable for indoor or outdoor applications and can … Read more

Surge Protection of Railway System (Traction system)

Surge Protection of Traction System Q. Explain with neat sketch protection of locos against lightening surges. There is a wide expansion of the track electrification worldwide. We often forget the hidden enemy and widespread damage that comes with overvoltage power surges. The easiest ways to understand are those which are derived from the lightning strikes … Read more

Railway Traction Transformer Tab Changer working and Construction

Tap Changer Q. Explain the purpose of equipments in AC locomotive : Tap changer. Tap changers are of many types such as On-Load tap changers and Off-Load tap changers. In traction power circuit mainly on load tap changers are preferred. On load tap changers are capable of changing the taps quickly without interrupting the flow … Read more

Linear induction motor, Moving Secondary Fixed Primary Single Sided LIM

Moving Secondary Fixed Primary Single Sided Linear Induction Motor As from the name suggests, in this type of linear motor the secondary is moving and the primary is fixed as shown in the Figure The operating principle is same as that of that the above Moving Primary Fixed Secondary Single Sided LIM. The only difference is … Read more

LEM Propelled Traction

LEM Propelled Traction A Linear induction asynchronous linear induction motor that works on the same principle as that of other conventional induction motor but it is typically designed to directly produce motion in a straight (Linear) direction. Electric Motor (LEM) is an Whenever there is a relative motion between the field and the short circuited … Read more

Induction Motor Operating as a Generator

Induction Motor Operating as a Generator When run faster than its synchronous speed, an induction motor runs as a generator called a Induction generator. It converts the mechanical energy it receives into electrical energy and this energy is released by the stator (Figure 2). (Figure 1) shows an ordinary squirrel-cage motor which is driven by … Read more

What is Potential Transformers (PT), CT and PT Connection with Wattmeter

Potential Transformers These transformers are extremely accurate-ratio step-down transformers and are used in conjunction with standard low-range voltmeters (usually 150-V) whose deflection when divided by voltage transformation ratio, gives the true voltage on the high voltage side. In general, they are of the shell-type and do not differ much from the ordinary two-winding transformers discussed … Read more

Triac Operates Dimmer, Electronic Dimmer

Dimmers Different lamps/luminaires produce light with constant brightness once they are switched on. For the following spots, the variation of brightness of the lamps is required. For (i) Photo studios (ii) Stage (iii) Drama theatres (iv) Decorations (v) Various functions. The device for controlling the brightness is a “Dimmer”. Dimmer is an electrical and or … Read more

Thyristor Operated Dimmer, Electronic Dimmer

Dimmers Different lamps/luminaires produce light with constant brightness once they are switched on. For the following spots, the variation of brightness of the lamps is required. For (i) Photo studios (ii) Stage (iii) Drama theatres (iv) Decorations (v) Various functions. The device for controlling the brightness is a “Dimmer”. Dimmer is an electrical and or … Read more