- The resistor which is used to slow down or stop the speed of a mechanical system by generating a braking torque is known as a braking resistor.
- These resistors are designed with some specifications like resistance & average braking power.
- Braking resistors including smaller ohmic values will help to control the speed of a motor & dissolve more heat.
- It provides higher reliability with less service. These resistors are mostly chosen over friction brakes to control motors.
- A braking resistor is required where when there is frequent tripping on the drive due to overvoltage, reduced equipment life, high maintenance costs, or motor and drive damage and overheating.
- We know that resistors consume heat and are used to slow down or stop a mechanical system.
- The energy which is generated by the motor during deceleration is too dissipated, so it helps to prevent damage to the drive which can happen due to overvoltage.
Working of Braking Resistor
- A braking resistor helps to stop or slow down a motor by dissipating the high voltage produced by the decelerating electric motor.
- This dissipated energy can be handled by the resistor to ensure that the increased voltage is kept to secure levels to avoid damage to the drive.
- So that equipment allows faster braking & avoids the overheating risk.
- The working principle of the braking resistor is when the motor is in working condition then the supply gives a high amount of current.
- One side of the load connected to the motor is stopped then it disconnects the supply to the motor. This small break in the power supply will lead to an accumulation of energy by the load.
- The inductive load is disconnected from its power source it takes time for it to discharge its stored energy back into the power source.
- During this time, if there is no provision for discharging this energy, then it can lead to severe damage to the equipment connected to that load.
- To avoid such situations, we use braking resistors in series with loads such as motors that need immediate stopping when they are running at high speeds.
Application of Braking Resistor
- Braking resistors are used where the speed of a motor exceeds the speed that is set through the variable frequency drive (VFD) otherwise when rapid deceleration is necessary.
- These resistors are used in a motor control system to avoid hardware damage & faults within a VFD.
- These resistors are applicable in train systems & motor speeds.
- These resistors are required in particular operations because the motor controlled through the variable frequency drive acts as a generator & the power supply will be back to the VFD instead of to the motor.
- This resistor will help to stop or slow down a motor by dissipating surplus voltage produced by the decelerating motor.
