Electric Traction: Comparison between Mechanical Braking and Electrical Braking

Power SystemsUtilisation of Electrical PowerUtilization of Electrical EnergyElectric Power System

With the modern traction equipment, fast trains can easily achieve the desired acceleration. However, if the stopping system or braking system of the trains fail, it will cause a great disaster. Therefore, braking system of trains is very important. In this article, let's understand how mechanical breaking differs from electric breaking and which one is more efficient.

Mechanical Braking

Mechanical brakes are applied by brake shoes which are pressed with force against the wheel of the train. In mechanical braking, the braking force is generally produced by means of piston-cylinder arrangement. The movement of the piston is transmitted to the brake shoes through a system of levers.

Electric Braking

In electric braking, the kinetic energy of the moving parts of the motor is converted into electrical energy which is either dissipated in a resistor or returned to the supply source. Thus, electric braking is a system of braking in which a braking action is applied to an electric motor by causing it to act as a generator.

Comparison between Electrical Braking and Mechanical Braking

The following table highlights the points that differentiate an electrical braking system from a mechanical braking system −

Point of ComparisonMechanical BrakingElectrical Braking
CostThe initial cost of mechanical braking is low.Electrical braking has high initial cost.
MaintenanceMechanical braking requires frequent maintenance as it produces excessive wear and tear of brake shoes.Electrical braking requires very little maintenance because of absence of mechanical equipment.
Replacement of brake shoesDue to excessive wear and tear, mechanical braking requires frequent replacement of brake shoes.Electrical braking does not require replacement of brake shoes.
Maintenance costDue to constant wear and tear of brake lining, frequent adjustments are necessary to compensate the offset error, therefore maintenance cost of mechanical braking is high.Electrical braking requires less maintenance and hence, its maintenance cost is low.
Production of metal dustMechanical braking produces metal dust which causes wearing of bearings.In case of electrical braking, no metallic dust is formed.
Braking actionIf the mechanical brakes are not correctly adjusted, then sudden braking action produces shock, which results in discomfort to passengers.In electrical braking, the adjustment of braking system is easy and the braking action is gradual and smooth.
Heat production & its effectIn mechanical braking, heat is produced in brake shoes of brake lining, which may damage the brake lining and may result in failure of braking system.In electrical braking, heat is produced at a convenient place which is not harmful to the braking system.
Regenerative brakingIn mechanical braking, regenerative braking is not possible.In electrical braking, 60% to 80% of kinetic energy of moving parts can be fed back to the supply line in regenerative braking.
Used alone or supplementedMechanical braking alone can be used.Electrical braking is alone not sufficient, and it is supplemented by mechanical braking.
Holding torqueMechanical braking is applied to hold the system at any position.Electrical braking cannot produce holding torque.
EfficiencyMechanical braking is less efficient due to excessive wear and tear.Electrical braking is highly efficient.
raja
Updated on 27-Apr-2022 10:30:25

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