GE AF-650 GP Design And Installation Manual page 61

Application Setup Examples
selected in H-40 Configuration Mode, either in Advanced
Vector Control [4] Torque open-loop or Flux control closed-
loop with motor speed feedback [2]. Torque setting is
done by setting an analog, digital or bus controlled
reference. When running torque control it is recommended
to make a full Auto tune procedure as the correct motor
data are of high importance for optimal performance.
•
Closed-loop in flux mode with encoder feedback
offers superior performance in all four quadrants
and at all motor speeds.
•
Open-loop in Advanced Vector Control mode. The
function is used in mechanical robust
applications, but the accuracy is limited. Open-
loop torque function works basically only in one
speed direction. The torque is calculated on basic
6 6
of current measurement internal in the adjustable
frequency drive. See Application Example Torque
Open-loop
Speed/torque reference
The reference to these controls can either be a single
reference or the sum of various references including
relatively scaled references. The handling of references is
explained in detail later in this section.
The adjustable frequency drive is capable of controlling
either the speed or the torque on the motor shaft. Setting
H-40 Configuration Mode determines the type of control.
Speed control
There are two types of speed control:
•
Speed open-loop control which does not require
any feedback from the motor (sensorless).
•
Speed closed-loop PID control requires a speed
feedback to an input. Properly optimized speed
6-6
TM
AF-650 GP Design and Installation Guide
Selects which input to use as speed PID feedback in
PI-00 Speed PID Feedback Source.
Torque control
The torque control function is used in applications where
the torque on motor output shaft is controlling the
application as tension control. Torque control can be
selected in H-40 Configuration Mode, either in Advanced
Vector Control [4] Torque open-loop or Flux control closed-
loop with motor speed feedback [2]. Torque setting is
done by setting an analog, digital or bus controlled
reference. When running torque control it is recommended
to make a full Auto tune procedure as the correct motor
data are of high importance for optimal performance.
•
•
Speed/torque reference
The reference to these controls can either be a single
reference or be the sum of various references including
relatively scaled references. The handling of references is
explained in detail later in this section.
DET-767A
closed-loop control will have higher accuracy
than speed open-loop control.
Closed-loop in flux mode with encoder feedback
offers superior performance in all four quadrants
and at all motor speeds.
Open-loop in Advanced Vector Control mode. The
function is used in mechanical robust
applications, but the accuracy is limited. Open-
loop torque function works basically only in one
speed direction. The torque is calculated on basic
of current measurement internal in the adjustable
frequency drive.