
Functions
5.10 Technological functions
Frequency inverter
Operating Instructions, 08.10. 2008, t.b.d.
129
Braking methods depending on the drive inverter being used
Table 5- 37 Functions in relationship with the frequency inverters
SINAMICS G120
PM240
PM250
PM260
DC and compound brake
X
---
---
Dynamic braking
X
---
---
Regenerative braking
---
X
X
Advantages and disadvantages of the braking methods
●
DC brake
–
Advantage: The motor is braked without the frequency inverter having to convert the
braking energy
–
Disadvantages: Is only used for an OFF1 command, excessive motor temperature
rise, no defined braking response, no constant braking torque, braking energy
dissipated as heat.
●
Compound brake
–
Advantage: Defined braking response, the motor is braked without the frequency
inverter having to convert any significant amount of braking energy
–
Disadvantages: Is only used for an OFF1 command, no constant braking torque,
excessive motor temperature rise, braking energy is lost as heat.
●
Dynamic braking
–
Advantages: defined braking response, no additional motor heating, constant braking
torque
–
Disadvantages: A braking resistor is required, braking energy is lost as heat, the
permissible load of the braking resistor must be taken into account
●
Regenerative braking
Advantages:
–
The regenerative energy is not converted into heat, but instead, is fed back into the
line supply
–
Constant braking torque
–
The methods can be used in all applications
–
Constant regenerative operation is possible - e.g. when a crane load is being lowered