Final answer:
The different methods of braking of DC motors include dynamic braking, plugging, electromagnetic braking, and regenerative braking.
Step-by-step explanation:
In order to understand the different methods of braking of DC motors, it is important to first understand the concept of back electromotive force (back emf). When a motor is running, it generates a back emf which is opposed to the driving emf. This back emf is produced by the spinning rotor and opposes the flow of current into the motor. This effect is beneficial because it limits the current flowing through the motor, thus preventing overheating.
There are several methods of braking a DC motor:
- Dynamic Braking: In this method, the motor is disconnected from the power source and connected to a resistor. The kinetic energy of the moving rotor is dissipated as heat in the resistor, slowing down the motor.
- Plugging: Also known as reverse voltage braking, this method involves reversing the polarity of the power supply to quickly decelerate the motor. The motor effectively acts as a generator, converting kinetic energy into electrical energy, which is dissipated as heat.
- Electromagnetic Braking: This method uses strong magnetic fields to slow down the motor. Eddy currents are induced in a metal disc attached to the motor shaft, creating a magnetic field that opposes the rotation of the rotor. The energy of the rotating rotor is converted into heat, slowing down the motor.
- Regenerative Braking: This method is commonly used in hybrid and electric vehicles. When the motor is acting as a generator, the energy of the rotating rotor is converted into electrical energy, which is stored in a battery and can be used later to power the vehicle or supplement the main power source.