Braking Resistor | on ElectriciansForums

Discuss Braking Resistor in the UK Electrical Forum area at ElectriciansForums.net

Joined
Oct 27, 2020
Messages
1
Reaction score
0
Location
istanbul
What is a Braking Resistor Used For?
The main purpose of brake resistance is to help realize overhaul and engine braking by dissipating rheostatic resistors as heat and absorbing regenerated braking energy. In summary, the purpose of brake resistance is to slow down, control, or quickly stop an engine by absorbing the counter-electromotive force (also known as CEMF), keeping the engine in full safe tolerances to protect it from possible destruction and damage. If it is necessary to stop an engine that is out of power, if the inertia of the engine is too high, thanks to the kinetic energy it has at that moment, the engine continues to rotate for some time. As the engine continues to rotate, the engine works like a generator, feeding the network.
As a generator, the operating time must be kept short and this energy generated in the opposite direction must be converted to heat. The Inverter cuts off the power of the motor. It converts this energy, which works like a generator, to DC, and transfers it to the braking resistor at the appropriate power and ohms, which are connected to the braking resistor terminals. In this case, there are two important issues to consider. The Ohm of the braking resistor must not be less than the value written in the inverter catalog. If the written catalog is more than the value, the braking time is extended. The strength of the braking resistance may vary depending on the application in which the engine is used. Since an engine cannot produce more energy than its power, it is also clear that the power of the resistance will also be equal to the maximum power of the engine.
Broken down into easy pieces:
The motor is designed to take electrical energy and convert it into mechanical energy needed for an application.
The CEMF (known as the counter electromotive force) will be generated when the application needs to brake, reverse, or overhaul a possible load. Mechanical energy creates electrical energy and helps the motor effectively act as a generator.
This over-renewed energy will go to the VFD (especially the DC bus) when the engine is controlled by a VFD.
A brake transistor is connected to the DC bus for shunt (routing) power to the dynamic brake resistor when the DC bus voltage reaches a predetermined level.
The brake resistance distributes this energy safely as heat.
 
It is possible for a motor being used as a generator (regenerative brake) to develop more electrical output than it is rated for.
do it for too long and it will destroy itself.
as you say if it is going to a vfd this will often end up raising the voltage of the DC bus.
some devices use transistors to shunt it to a resistor, others as @static zap says, regenerate it to a suitable mains voltage and frequency and inject it back to grid.

Is there a question to your statement above or were you wanting people to validate it?
 

Reply to Braking Resistor in the UK Electrical Forum area at ElectriciansForums.net

News and Offers from Sponsors

  • Article
Join us at electronica 2024 in Munich! Since 1964, electronica has been the premier event for technology enthusiasts and industry professionals...
    • Like
Replies
0
Views
299
  • Sticky
  • Article
Good to know thanks, one can never have enough places to source parts from!
Replies
4
Views
807
  • Article
OFFICIAL SPONSORS These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then...
Replies
0
Views
852

Similar threads

Good one . Thanks. I was finding Fluke etc ÂŁÂŁÂŁ!
Replies
5
Views
2K

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

YOUR Unread Posts

This website was designed, optimised and is hosted by untold.media Operating under the name Untold Media since 2001.
Back
Top