Kollmorgen AKD series User Manual

AKD User Guide | 7 Configuring Drive Power
7.2 Regeneration
7.2.1 Overview
Regeneration, or "shunting", dissipates energy from the DC bus during deceleration of the motor load. During
deceleration, the motor acts as a generator that pumps energy back into the system. If this energy is not dis-
sipated, then the bus energy level can exceed acceptable levels (VBUS.OVFTHRESH). If the system exceeds
the maximum bus voltage, then the drive generates an over voltage fault (F501 and shuts down. A regeneration
resistor, or regen resistor, is an external device that dissipates excess energy and allows the drive to function nor-
mally during deceleration.
Follow these steps to determine the regen needs for your system and to configure the drive for regen:
1. Calculate motor peak and continuous regenerative energy and use this value to size the regen resistor.
2. Select a compatible regen resistor.
3. Configure regen parameter values in WorkBench.
7.2.2 Regen Resistor Options
In the Power screen, you can select from a variety of pre-sized regen resistors using the Regen Resistor Type
box.
When you select -1-External Regen, the Select resistor box appears and contains the pre-sized resistors for
your drive. Select the model regen resistor that you are using and the drive will populate the remainder of the
fields. If you are using a nonstandard resistor, then choose <User defined> and fill in the appropriate values for
your resistor.
If you use a nonstandard resistor, contact Kollmorgen technical support
to confirm that the nonstandard resistor will work correctly with your sys-
tem.
7.2.3 Calculating Motor Peak Energy and Regen Resistor Size
In order to determine whether or not your system requires a regen resistor, you must calculate the peak kinetic
energy that the motor generates during deceleration and the continuous regeneration energy created by the
motor. If this energy exceeds the drive capacity, then you need a regen resistor. In many cases, peak or con-
tinuous regenerated energy does not exceed the drive capacity and no regen resistor is needed.
The calculation for peak kinetic energy requires values for several factors that affect the generation of energy in a
motion system:
l Load inertia
l Motor inertia
l Motor speed from which deceleration occurs
l Time required to decelerate
54 Kollmorgen | December 2010

Kollmorgen AKD series Specifications

General

Continuous Current	Up to 180 A
Control Modes	Position, Velocity, Torque
Communication Interfaces	EtherCAT, CANopen, Modbus TCP/IP
Feedback Options	Resolver, Encoder
Safety Features	Safe Torque Off (STO), Safe Stop 1 (SS1)
Protection Features	Overvoltage, Undervoltage, Overcurrent, Short Circuit, Overtemperature
Switching Frequency	8 kHz, 16 kHz
Ambient Temperature	0°C to 40°C
Operating Temperature	0 - 40 °C (derating may apply)
Humidity	5% to 95% non-condensing