Home | | Basic Electrical and Instrumentation Engineering | | Electrical Machines II | Induction Motor Braking Regenerative Plugging Dynamic

Induction Motor Braking Regenerative Plugging Dynamic - | Study Material, Lecturing Notes, Assignment, Reference, Wiki description explanation, brief detail |

Chapter: Electrical machines - Starting and Speed Control of Three Phase Induction Motor

Induction Motor Braking Regenerative Plugging Dynamic

Regenerative Braking of Induction Motor, Braking of Induction Motor, Plugging Braking of Induction Motor.

Induction Motor Braking Regenerative Plugging Dynamic

 

Braking of Induction Motor

 

Under Digital Electronics

 

Regenerative Braking of Induction Motor • Plugging Braking • Dynamic Braking

 

Induction motors are used at various places. Speed control of induction motors is quite difficult and that’s why their use was restricted and DC motors had to be used as their speed regulation was possible. But when induction motor drives were invented and implemented, they were given preference because of many advantages over DC motors. Whenever controlling of motors is done, braking is the most important term, so as with induction motors. Induction motor braking can be done by different methods, which are

 

i.                                   Regenerative braking of induction motor

 

ii.                                  plugging Braking of induction motor

 

iii.                                 Dynamic braking of induction motor is further categorized as

 

a) AC dynamic breaking

 

b) Self excited braking using capacitors

 

c) DC dynamic braking

 

d) Zero Sequence braking

 

Regenerative Braking of Induction Motor

 

We know the power (input) of an induction motor is given as.


 

Here, φs the phase angle between stator phase voltage V and the stator phase current Is. Now, for motoring operation φs < 90° and for braking operation φs > 90°. When the speed of the motor is more than the synchronous speed, relative speed between the motor conductors and air gap rotating field reverses, as a result the phase angle because greater than 90° and the power flow reverse and thus regenerative braking takes place. The nature of the speed torque curves are shown in the figure beside. It the source frequency is fixed then the regenerative braking of induction motor can only take place if the speed of the motor is greater than synchronous speed, but with a variable frequency source regenerative braking of induction motor can occur for speeds lower than synchronous speed. The main advantage of this kind of braking can be said that the generated power is use fully employed and the main disadvantage of this type of braking is that for fixed frequency sources, braking cannot happen below synchronous speeds.

 

Plugging Braking of Induction Motor

 

Plugging induction motor braking is done by reversing the phase sequence of the motor. Plugging braking of induction motor is done by interchanging connections of any two phases of stator with respect of supply terminals. And with that the operation of motoring shifts to plugging braking. During plugging the slip is (2 - s), if the original slip of the running motor is s, then it can be shown in the

Study Material, Lecturing Notes, Assignment, Reference, Wiki description explanation, brief detail


Copyright © 2018-2021 BrainKart.com; All Rights Reserved. (BS) Developed by Therithal info, Chennai.