Deepakkumar Yadav
Unbalanced System A system is said to be balanced system if the impedance or phase angle or frequencies of three phase is same otherwise it is called as unbalanced system. There are two types of unbalanced systems. Those are Three phase four wire system (star connection with neutral) Three phase three wire system (Delta or … Read more
Lightning Arrester for Traction Systems 1. DC Traction Arrester2. Track Side Arrester3. AC Surge Arrester4. Low Voltage Limiter 5. Enhanced Voltage Limiter This is installed in between the current return path and the structures lying alongside to the rails, such as telecommunication, signalling and electrical equipment. In case of over voltages, enhanced voltage limiter generates … Read more
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 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
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
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 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 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
Direct online Line Stater or DOL Motor Starter The Direct On Line starter is the simplest form of motor starter. The direct online starter is a basic and simple starter used for starting the induction motor. In DOL Starter the stator winding of the induction motor is directly connected to three phase supply voltage. Thus, … Read more
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