User guide

Operational Theory Xenus XTL User Guide
34 Copley Controls Corp.
2.15: Regen Resistor Theory
2.15.1: Regeneration
When a load is accelerated electrical energy is converted into mechanical energy. During
deceleration the conversion is reversed. This is called regeneration. Some of this regenerated
energy is lost to friction in the mechanical system. More of this energy is converted to heat due to
I
2
R losses in the motor windings, cabling, and drive electronics. The remainder of the energy is
added to the electrical energy already stored in the internal capacitor bank of the amplifier. The
result of this energy being added is an increase in the voltage on the capacitor bank.
2.15.2: Regen Resistor
If too much energy is added to the capacitor bank, the voltage rises to a point where the
amplifier's over voltage protection shuts down the amplifier. To prevent this, a regen circuit shunts
some of the energy into an external regen resistor when the voltage rises too high.
2.15.3: Regen Circuit Components
The amplifier provides an internal transistor that is used in combination with an external resistor.
Copley Controls supplies compatible resistors as described in Regen Resistor Assemblies (p.
169). When using a resistor acquired from another source, be sure it meets the specifications
described in Regen Resistor Sizing and Configuration (p. 137).
2.15.4: Regen Circuit Protections
The amplifier protects the regen circuit against short circuit, and uses I
2
T peak current/time
algorithms to protect both the external resistor and the internal transistor.
2.15.5: Configurable Custom Resistor
The following values can be entered for a custom resistor using CME 2:
Option Description
Resistance Value Value in ohms of the resistor
Continuous Power Continuous power rating of the resistor
Peak Power Peak power rating of the resistor
Time at Peak Power Time at peak power of resistor
For more information, see Regen Resistor (p. 94) and
Regen Resistor Sizing and Configuration (p. 137)