A braking resistor is a high- wattage resistor used in motor control to help a motor stop quickly through a process known as dynamic braking.
When disconnected power supply to motor. The motor acts as generator, converting mechanical power back to electrical power. This power is returned to the drive’s dc link element (capacitor or reactor). A dc link connected electronics power switch or braking dc chopper control dissipation of this power. As heat in a set of resistors cooling fans may be used to prevent resistor overheating.