Regenerative braking works by converting the kinetic energy of a moving vehicle or object into electrical energy when slowing or stopping. This electrical energy can either be used immediately or stored for later use. Specifically, regenerative braking in a DC motor involves changing the thyristor connections so that the motor operates as a generator when rotating under inertia, returning the generated electrical energy back to the power source through diode rectification. This saves energy that would otherwise be wasted through conventional braking methods.

1. REGENERATIVE BRAKING
CONTROL

2. DEFINITION
A regenerative brake is
an energy recovery
mechanism which slows
a vehicle or object down
by converting its kinetic
energy into another
form, which can be
either used immediately
or stored until needed.

3. BRIEF
The mode of operation of a d.c motor changes from motoring action to
regenerative braking when the motor is already rotating with a high inertia load
& it is intended to apply a brake to stop the motor.
Instead of wasting the energy due to inertia of motion by applying either a
mechanical brake or wasting the energy through a resistance, the inertia of the
load is allowed to drive the motor as a generator & spend its inertial energy.
The motor thus will be able to return energy to the source & this will lead to
energy saving.

4. For regenerative
braking, the
thyristor
connections have to
be changed.
The motor is
separately excited.
This may happen in
situations like when
inertia of a running
train or a vehicle
would be rotating
the motor.
Let the motor
load(may be a fly
wheel) rotating the
motor due to inertia
& the motor is free
for regenerative
braking operation

5. CIRCUIT DIAGRAM

6. WORKING
At that time if the thyristor switch, T(or
we could use a power transistor switch)
is made ON, the motor terminals will
virtually get short circuited and a very
heavy current will flow through the
armature & T.
Energy will be stored in the inductance
of the armature circuit. Now, if the
chopper switch is made OFF diode, D
will be turned ON & the energy stored
in the inductance would be returned to
the source of supply.

7. REGENERAITVE BRAKING OF A SEPERATELY-
EXCITED D.C MOTOR
CIRCUIT DIAGRAM
CORRESPONDING
WAVEFORM

8. Rheostatic Braking
In rheostat
braking the
kinetic energy
of the motor
load rotates
the motor as a
generator.
The energy, so
generated,
instead of
returning to the
source of supply
is allowed to be
dissipated in a
rheostat.
This resistance Rl
could be a
heater oil in a
car or in an
electric train or
in a Mass Rapid
Transit(MRT)
system.
The heat
generated is
utilized in
heating the
chambers/com
partments of
the vehicle in
winter season.

9. CIRCUIT DIAGRAM

10. THANK
YOU!!!..