What type of supply is used in electrical traction?

The system which use electrical power for traction system i.e. for railways, trams, trolleys, etc. is called electrical traction. The track electrification refers to the type of source supply system that is used while powering the electric locomotive systems. It can be AC or DC or a composite supply.

Which relay is suitable for catenary protection?

2.1 Distance protection using ‘Mho’ relay. Type YCG 14. At present, electromechanical type ‘Mho’ relays are used for protection against catenary-to-earth faults. The maximum torque angle of this relay is 75°.

Which type of DC motor is used for electric traction?

1. DC shunt motor is a constant speed motor but for traction purpose, the speed of the motor should vary with service conditions. 2. In case of DC shunt motor, the power output is independent of speed and is proportional to torque.

What is safety relay in locomotive?

The relay protects from over current drawn by 25kV system in the locomotive namely transformer, tap changer, roof bushing etc and also acts as a secondary protection for rectifier and traction motor. Relay is popularly called QLM relay. Any fault in the transformer, causes QLM tripping as well as safety value blowing.

Which motor is used in traction?

DC motors
Explanation: DC motors are used for traction as, according to the characteristics of DC motors speed is inversely proportional to torque and square of armature current as well, if linear magnetization is concerned. Thus, DC motors are perfectly suitable for traction.

What is induction Cup relay?

Induction Cup Relay. The relay which works on the principle of electromagnetic induction is known as the induction cup relay. The relay has two or more electromagnet which is energized by the relay coil. The static iron core is placed between the electromagnet as shown in the figure below.

Which is an instantaneous relay?

An Instantaneous Relay is one in which there is no time delay provided intentionally. As the current coil is an inductor, there would be a certain delay to reach the current in the coil to its maximum value. These relays can be operated in less than 0.1 sec. …

Why is DC series motor used in traction?

DC Series motor has high rate of acceleration and retardation. DC Series motor is variable speed motor. Due to these characteristics motor is protected against overload. DC series motor has develops high torque at low speeds, low torque at high speed, this is the basic requirement of traction unit.

What is traction inverter?

Traction inverters convert dc power from an on-board high voltage (HV) battery into ac power to drive the main motor or motors of an electric vehicle. In addition, traction inverters perform functions such as voltage boosting, switch protection and regenerative braking.

What is DJ in locomotive?

DJ is Disc Joint.It is also called as VCB. This is the terminology used under AC operating conditions.While in case of DC we have DS that is Disconnecting Switch. The basic difference between DS and DJ is that DS can be set manually but not DJ.The main …