PROGRAMMING
SINUS K
MANUAL
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3.6.
SENSORLESS VECTOR CONTROL (VTC SW only)
Sensorless vector control is the most advanced control technique of an asynchronous motor.
Processing the equations controlling the operation of an asynchronous motor both at constant speed and during
transients, sensorless vector control decouples the torque control from the motor flux control with no need to use any
speed transducer or position transducer.
This allows to control the connected motor torque or mechanical speed under any load condition and within a speed
range ranging from 0 to three times the motor rated speed.
The operator should know the parameters of the asynchronous machine equivalent circuit in order to use sensorless
vector control (see Fig. 14).
l
2
l
1
R
s
i
s
V
s
M
R
R
S
Figure 14: Equivalent circuit of the asynchronous machine
Where:
R
S
: Stator resistance (wiring included)
R
R
: Rotor resistance
l
1
+l
2
: Full leakage inductance
M : Mutual inductance (not required for control enabling)
S : Slip
Because motor parameters are usually unknown, SINUS K is capable of automatically detect them. This is done by
producing adequate DC voltage models with no machine rotation (see section 2.2 “STARTUP PROCEDURES” in the
Installation Manual).
Manual adjustment is also possible to fine–tune the parameter values for specific applications.
