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Polarity of supply voltage is reverse in which braking
Regenerative braking
Dynamic braking
Plugging
None of these
Plugging
Plugging, also known as reverse current braking, is a method of electric braking where the polarity of the supply voltage is reversed to force the motor to develop torque in the opposite direction. This produces a powerful braking action by causing the motor to act as a load and dissipate energy rapidly.
Plugging, also known as reverse current braking, is a method of electric braking where the polarity of the supply voltage is reversed to force the motor to develop torque in the opposite direction. This produces a powerful braking action by causing the motor to act as a load and dissipate energy rapidly.
TbтАЛтИЭтИТ(V+EbтАЛ) тАФ Net braking torque generated during plugging
IplugтАЛ=RaтАЛ+RextтАЛV+EbтАЛтАЛ тАФ High peak current during braking
In plugging, the terminals of the supply are interchanged while the motor is running. This creates a back EMF that acts in the same direction as the supply voltage, resulting in a very high reverse current. The machine experiences an intense electromagnetic torque opposing the direction of rotation, causing rapid deceleration to zero speed.
Plugging involves reversing supply terminal polarity.
It provides the highest braking torque among common methods.
It causes heavy current spikes, requiring external resistances for current limitation.
The motor must be disconnected from the supply at zero speed to prevent reversal.
Extremely fast deceleration
High braking torque at standstill
High heat dissipation in windings
High peak currents can damage motor insulation
Requires mechanical interlocking to prevent reverse rotation
Lifts and elevators
Rolling mills
Printing presses
Regenerative braking returns power to the source by operating the machine as a generator.
Dynamic braking dissipates kinetic energy as heat in a resistor without supply reversal.
Plugging is also known as counter-current braking.
C is correct тАФ Plugging is the braking method where the supply voltage polarity is reversed, forcing the motor to generate torque in the opposite direction.
In competitive exams, always remember that plugging is the only braking method that can provide torque at zero speed, making it essential for precision stops in industrial drives.