Chopper

Notice

Damage if operated without parameterization

If the chopper threshold is set too low, the braking resistor may be permanently active. This causes the box to overheat. Material damage is possible.

  • Only apply UP to the box after parameterization.
  • Set the parameters so that the following condition is always met:

 

Chopper 1:

Vth: 8000:11 "Chopper threshold overvoltage".

Vhyst: 8000:13 "Chopper hysteresis voltage".

Up,max: Nominal voltage UP plus the maximum tolerance upwards.

Notice

The chopper is disabled in case of overtemperature

Overvoltages are no longer dissipated in case of overtemperature. Defect possible due to overvoltage.

  • Monitor the bit I2T warning in order to recognize a temperature increase in good time.
  • If necessary, disable the drive if the bit I2T error is TRUE.

The chopper is automatically activated when the voltage UP exceeds the limit value "Chopper threshold overvoltage". The chopper controls the current through the braking resistor such that the voltage UP does not increase further.

The chopper is automatically deactivated when the voltage UP has dropped again by the "Chopper hysteresis voltage".

Parameter

Index
(hex)

Name

Description

Data type

Flags

Default

8000:11

Chopper threshold overvoltage

The Chopper is switched on if the voltage UP exceeds this value.

Unit: mV.

UINT32

RW

50000dec

8000:13

Chopper hysteresis voltage

Hysteresis voltage for switching off the Choppers.

Unit: mV.

UINT32

RW

1000dec

The following diagram shows the influence of the parameters on an exemplary curve of the voltage UP:
Chopper 2: