General Constraints Of Sensorless Control With The Injection Procedure; Commissioning At The Sensorless Operation Of The Synchronous Machine - Baumuller b maXX BM3000 Operating Manual

Description of the Software Modules and Parameters
The torque display requires an exact dead time compensation at low speeds in the con-
trolled operation. In order to improve the accuracy of the torque, a fine adjustment of the
dead time compensation can be carried out at speed 0 via bit 9 of parameter Z133.1–.

4.8.10.1 General constraints of sensorless control with the injection procedure

The injection procedure for the sensorless control of the SM can only be operated, if
m the energy transducer possesses an iron-core magnetic with pronounced saturation ef-
m the magnetic symmetry of the three phases is existent
Because of the constraints, which are listed above, the operation of sensorless control of
the SM, as well as the use of method 2 of notch position search is only then possible, if
the machines have been tested successfully.
Constraints of the sensorless control at very low speed
The operation is also possible at very low speed and at standstill. Because of the higher
torque ripple, however, the motor may run irregularly.
Switch on / Enable at rotating machine
At first there is no speed or position information available, when enabling the drive in the
sensorless operation. At each switching on of the drive the initial rotor position is deter-
mined on the basis of the HF-injection. Additionally there is the option to synchronize to
the moving motor.

4.8.10.2 Commissioning at the sensorless operation of the synchronous machine

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fects (it cannot be used on rotating and linearly ironless machines) and
Selection of the motor from the motor database of ProDrive or the setting of the data
with the help of the motor type plate. The following values are necessary: nominal cur-
rent, nominal speed, pole pair number, EMF-constant. The DC-link nominal value
must conform with the actual DC-link value.
Execute measurement of stator resistance and Lq-inductance of the motor as well as
the dead time of the power unit with the help of the function self-optimization.
Calculate the current controller parameters with the measured values for stator resis-
tance and the Lq-inductance.
Accept the measured motor parameters and the dead time compensation for the mo-
tor control in the self-optimization.
Setting of both compensating controllers (for HF injection and voltage model). A basic
setting can be made with ProDrive.
Setting of the smoothing time for the determined actual speed value, proposed value
range between 1 and 5 ms. The greater the inertia torque of the drive is, the greater
the smoothing time may be selected.
Set speed controller (at sensorless operation a torque inertia measurement is not
possible).
Store data set.
Parameter manual b maXX BM3000
Document no.: 5.12001.07
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