Sanyo Denki PY2A030 - External Regeneration Resistors; When to Use an External Regeneration Resistor; Table 15: Amplifier Regeneration Power

PY Manual Copyright © 2006 SANYO DENKI AMERICA, Inc.
47
External Regeneration Resistors
When operating, servo systems transform electrical energy to mechanical energy to
accelerate the motor and to overcome system losses such as friction. When a moving
load is decelerated, or another system is “pulling” the load, the servo system converts this
mechanical energy into electrical energy, which is then dissipated as heat in a resistor.
This resistor is called a regeneration resistor or regen resistor for short. The amplifier has
an internal regen resistor which is adequate for most applications. Connections are
provided for an external regen resistor if more capacity is required.
Applications with a load that moves in a vertical direction, applications with load inertia
that is high relative to the motor (15:1), and applications where the motor is used to
provide a tension load are most likely to require external regen resistors. In order to
determine if an external resistor is required, the amount of energy generated must be
calculated and then compared to the capacity of the internal resistor. An external
regeneration (Regen) resistor is used when the internal regeneration resistor’s allowable
power is exceeded. See the table below.
Table 15: Amplifier Regeneration Power
Maximum Regeneration Power [W]
Drive Model
Internal
Maximum available
from AI
PY2A015 0 220
PY2A030 0 220
PY2A050 60 220
PY0A015 20 220
PY0A030 20 220
PY0A050 60 500
PY0A100 90 500
PY0A150 120 500
Calculating Regeneration Power
The formulas below may be used to calculate the amount of power generated by the
moving load. There are separate formulas for horizontal moving loads and vertical loads.
P
M
= Regeneration power [W]
E
M
= Total regeneration energy [J]
E
Hb
= Regeneration energy during deceleration [J]
E
VUb
= Regeneration energy during up decel [J]
E
VD
= Regeneration energy during down drive [J]
E
VDb
= Regeneration energy during down decel [J]
K
E
= Motor voltage constant [V / RPM]
K
T
= Motor torque constant [Nm / A
rms
]
N = Motor speed [RPM]
T
b
= Torque during acceleration [Nm]
When to use an
External
Regeneration
Resistor
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com