GE Industrial Solutions AF-650 GP General Purpose Drive - Manual (Page 18)

6.1.3 Calculation of Braking Power
When calculating the braking power, it is to be ensured that the brake resistor is able to handle the average power as well as the peak power. The average power
is determined by the process period time, i.e. the length of the braking time in relation to the process period time. The peak power is determined by the braking
torque, which means that as braking progresses, the brake resistor must be able to dissipate the energy input.
The illustration below shows the relation between the average power and the peak power.
Illustration 6.2: Relation between average power and the peak
power.
6.1.4 Calculation of the Brake Resistor Peak Power
P
peak, mec
is the peak power by which the motor brakes on the motor shaft. It is calculated as follows:
Ppeak, mec = Pmotor × MBR(%) W
P
peak
is the name used for the braking power dissipated to the brake resistor when the motor brakes.
P
peak
is lower than P
peak,mec
since the power is reduced by the efficiencies of the motor and the frequency converter.
The peak power is calculated as follows:
Ppeak = Pmotor × MBR(%) × ηmotor × ηDRIVE W
AF-650 GP Brake Resistor Design Guide
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