Overload Protection - ABB IRB 6400R Product On-Line Manual

Servo System
The following diagrams outline the system structure for AC operation as well as the
fundamental structure of the drive unit.
AC OPERATION
TORQUE
reference
ESTIMATOR
ROTOR
POSITION
Figure 13 System structure for AC operation.

3.4 Overload protection

PTC resistance is built into the robot motors to provide thermal protection against over-
loads. The PTC sensors are connected to an input on the panel unit which is sensitive
to resistance level and which check that low resistance is maintained.
The robot computer checks the motors for overloading at regular intervals by reading
the panel unit register. In the event of an overload, all motors are switched off.
16
Computer
Rotor position
DC link
Drive Unit
-
+
CURRENT
-
+
CURRENT
REGULATOR
Serial measurement
Torque reference
M
PWM
PWM
PWM
System Description
board
R
DC link
+
-
U
+
W
-
V
+
-
MAIN
CIRCUITS
Product Manual
M