Plugging is the most powerful method of braking an electric motor, consisting of actively applying power to the motor in the opposite direction of its rotation. This is analogous to reversing the engine thrust of a power boat or an airplane in order to quickly bring it to a halt. For a VFD, this means a reversal of phase rotation while carefully applying power to the AC induction motor.
Like DC injection braking, plugging requires power be applied to the motor in order to make it stop, and it also results in all the kinetic energy being dissipated in the rotor. The advantage held by plugging over DC injection braking is that the braking torque may be maintained and precisely controlled all the way to zero speed.
Summary:
Plugging is one of the braking methods used for braking AC motors. List of all braking methods:
- DC injection braking
- Dynamic braking of AC Induction Motors
- Regenerative braking of AC Induction Motors
- Braking using Plugging
References/Further reading:
- AC Motor Braking methods PDF Handbook extracted from Instrument Handbook authored by Tony R Kuphaldt under CC4.0L
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