WEG CFW300 V1.3X, Programming Manual

Page: 117 / 157

Dynamic Braking
CFW300 | 13-1
13
13 DYNAMIC BRAKING
The braking torque that can be obtained through the application of frequency inverters without dynamic braking
resistors varies from 10 % to 35 % of the motor rated torque.
In order to obtain higher braking torques, resistors for dynamic braking are used. In this case the regenerated
energy is dissipated on the resistor mounted externally to the inverter.
This type of braking is used in the cases when short deceleration times are wished or when high inertia loads
are driven.
The Dynamic Braking function can only be used if a braking resistor has been connected to the CFW300, and if
the parameters related to it have been adjusted properly.
P153 - Dynamic Braking Level
Adjustable
Range:
348 to 460 V Factory
Setting:
According to
Table 13.1 on
page 13-1
Properties:
Description:
The parameter P153 defines the voltage level for the braking IGBT actuation, and it must be compatible with
the power supply voltage.
If P153 is set at a level too close to the overvoltage actuation level (F022), it may occur before the braking
resistor can dissipate the motor regenerated energy.
Table 13.1 on page 13-1 contains the adjustment ranges
for the actuation of the dynamic braking according to the model.
Table 13.1: Dynamic Braking actuation value
Input Voltage P0153 Actuation Band P0153 Factory Default
100 to 127 Vac 391 to 460 Vdc 395 Vdc
200 to 240 Vac 348 to 410 Vdc 365 Vdc
The Figure 13.1 on page 13-2 shows and example of typical DC braking actuation, where the hypothetical
wave shapes of the voltage on the braking resistor and the DC link voltage can be observed. Thus, when the
braking IGBT connects the link to the external resistor, the DC link voltage drops below the value set by P153,
keeping the level below fault F022.