Drive Regeneration; Akd Pdmm-X00306 To Akd Pdmm-X00606; Akd Pdmm-X01206 To Akd Pdmm-Xzzz07; Emergency Stop - Kollmorgen AKD PDMM series User Manual

AKD PDMM User Guide | 10.4.1 Drive Regeneration
fully in hardware. When activated, the drive shorts the motor terminals in phase with the back EMF (q
axis) but continues to operate the non-force producing current loop (d-axis) with 0 current. This action
forces all of the dynamic braking current toward stopping the motor current and insures the fastest stop-
ping of motor terminal current.
The drive hardware also limits the maximum dynamic braking motor terminal current via the DRV.DBI-
LIMIT parameter to prevent the drive, motor, and customer load from encountering excessive cur-
rents/forces. When the current is not being limited, the mechanical energy is dissipated in the motor
terminal resistance. When the current is being limited, energy is returned to the drive bus capacitors.
When the amount of returned energy raises the bus capacitor voltage enough, the drive activates the
regeneration control to start transferring the returned energy to the regen resistor. This resistor could be
internal or external to the drive depending on drive model and drive wiring.
Whether and how the drive uses dynamic braking mode depends on the drive disable mode (DRV.DI-
SMODE) setting.

10.4.1 Drive Regeneration

When the servo motor is slowing down at a rate faster than friction and motor losses would slow the
motor, then mechanical energy can be returned to the drive. This returned energy initially drives the inter-
nal bus voltage upwards. When the returned energy is high enough, the regeneration control transfers the
excess returned energy into the regeneration power resistor. If the regeneration control cannot fully handle
the power returned (for example, because there is not a regen resistor present or its resistance value is too
high), then the bus voltage will continue to rise and a bus over voltage fault will happen and disable the
drive completely, which allows the motor to freewheel.

AKD PDMM-x00306 to AKD PDMM-x00606

These units do not have an internal regeneration resistor. In many applications machine friction, motor
losses, and the limited bus capacitor energy absorption handles the application. But, depending on the
exact application requirements, an external resistor can be connected.

AKD PDMM-x01206 to AKD PDMM-xzzz07

These units have an internal regeneration resistor plus the capability to connect an external resistor if
higher power levels are needed.
Related Topics
See section 6.14 Dynamic Braking in the AKD PDMM Installation Manual for detailed information on
dynamic braking.
DRV.DISMODE (pg 273)
DRV.DBILIMIT (pg 268)

10.5 Emergency Stop

10.5.1 Stop / Emergency Stop / Emergency Off

The control functions Stop, Emergency Stop and Emergency Off are defined by IEC 60204. Notes for
safety aspects of these functions can be found in ISO 13849 and IEC 62061.
68 Kollmorgen™ | December 2012
The parameter DRV.DISMODE must be set to 2 to implement the dif-
ferent stop categories. Consult the AKD PDMM User Guide for con-
figuring the parameter.