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Description of the Software Modules and Parameters
4.4.5.3 Identification of the nonlinear parameters
The identification of the nonlinear parameters Lq, Ld and the magnetic flux is executed in
speed control operation. ProDrive executes this automatically. The inductance is mea-
sured during ramp-up, in which both currents Iq and Id were kept constant. Therefore the
corresponding inductances can be found for each current combination Iq and Id.
The following settings may be entered:
4.4.5.4 Field weakening at IPMSM
If a voltage limit is reached at the controller, the field weakening controller interferes at
the BM3300. In contrast to synchronous and asynchronous motors a higher torque can
be reached with field weakening at IPMSM, because the additional Id current effects a
reluctance torque.
The required curves of an IPMSM are shown in
motor works on the MTPA curve (red). If an additional Id current is supplied, the state
shifts left (greater Id current). The Id current can be increased up to the MTPF curve (max-
imum torque per flux) at field weakening. The maximum torque is reached here at an
available flux. At a greater Id current the motor needs higher voltage to reach the desired
torque. If the available flux reduces further, the maximum Iq current is reduced and the
current pointer always positions itself along the MTPF curve up to the zero point of the
flux. So it is secured that always the maximum torque can be reached.
– After this the speed controller must be set. A good setting can be determined with a
control loop analysis.
– Subsequently Lq, Ld and the magnetic flux must be mapped in the controller. There-
fore are two options:
n If the parameters are known, they can be loaded via a csv-file.
n If they are not known, an automatic identification can be executed with ProDrive
(see chapter Z4.4.5.3–).
– In conclusion the current controllers must be optimized again. The optimization is
executed according to the table values of Lq(0,0) and Ld(0,0).
– Standardization current for the curve family
n This is the maximum current as far as the identification is executed. From 0 A up
to this value the currents were varied in ten equal distances and the measure-
ments were executed.
– Ramp function generator
n The ramp-up time must be set to 0 seconds, so that the speed controller is directly
limited at a speed jump.
– Set value generator
n The set value generator should alternately generate values from 0 up to a suffi-
cient high speed in order to get enough measuring values during the ramp-up.
ZFig.
77–. Without field weakening the
Parameter manual b maXX BM3000
Document no.: 5.12001.07
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