Braking resistor
In regenerative braking mode, the electric motor feeds braking energy into the intermediate circuit of the frequency inverter, causing the intermediate circuit voltage to rise. A braking resistor absorbs this energy and converts it into heat: part of it immediately, the rest after the braking process has been completed and the resistor has cooled down.
The characteristics of the load cycle (duty cycle / braking time and cycle time) are therefore important for the design of the braking resistor. In addition, the braking power PBr , i.e. how quickly the energy is dissipated, and the minimum resistance value Rmin , which is specified by the frequency inverter, are required.
The resistance value recommended by us is significantly higher than the minimum resistance value due to manufacturing tolerance and temperature coefficient. A safety margin of approx. 20% is calculated here (R = 1.2 x Rmin). This rules out possible damage to the inverter components due to excessive currents.
We will be happy to calculate the necessary braking resistor for the corresponding duty cycle ED based on the braking power, braking time and min. resistance value specified by you. Please send an e-mail to service@elektromotoren.de.