Motor parameter identification using MID
The whole MID is controlled via the FreeMASTER "Variable Watch". Motor Identification (MID) sub-block shown in
. The
motor parameter identification is as follows:
1. Set the
MID: Command
variable to STOP.
2. Select the measurement type you want to perform via the
MID: Measurement Type
variable:
• PP_ASSIST - Pole-pair identification assistant.
• EL_PARAMS - Electrical parameters measurement.
• Ke - BEMF constant measurement.
• MECH_PARAMS - Mechanical parameters measurement.
3. Insert the known motor parameters via the
MID: Known Param
set of variables. All parameters with a non-zero known value
are used to infer other parameters (if necessary).
4. Set the measurement configuration paramers in the
MID: Config
set of variables.
5. Start the measurement by setting
MID: Command
to RUN.
6. Observe the
MID Start Result
variable for the MID measurement plan validity (see
) and the actual
MID: State
,
MID:
Faults
(see
MID: Warnings
(see
) variables.
7. When the measurement is successfully finished, the measured motor parameters are in the
MID: Measured
set of variables.
MID faults and warnings
The MID faults and warnings are saved in the format of masks in the
MID: Faults
and
MID: Warnings
variables. Faults
and warnings are cleared by automatically starting a new measurement. If a MID fault appears, the measurement process
immeadiatelly stops and brings the MID state machine safely to the STOP state. If a MID warning appears, the measurement
process continues. Warnings report minor issues during the measurement process. See
for more details on
individual faults and warnings.
Table 6. Measurement faults
Fault mask
Fault description
Fault reason
Troubleshooting
b#0001
Electrical parameters
measurement fault.
Some required value cannot
be reached or wrong
measurement configuration.
Check whether measurement
configuration is valid.
b#0010
Mechanical measurement
timeout.
Some part of the mechanical
measurement (acceleartion,
deceleration) took too long
and exceeded 10 seconds.
Raise the
MID: Config
Mech Iq Accelerate
or lower
the
MID: Config Mech Iq
Decelerate
.
Table 7. Measurement warnings
Warning mask
Warning description
Warning reason
Troubleshooting
b#0001
K
e
is out of range.
The measured
K
e
is negative.
Visualy check whether the
motor was spinning properly
during the
K
e
measurement.
The MID measurement plan is checked after starting the measurement process. If a necessary parameter is not scheduled for the
measurement and not set manually, the MID is not started and an error is reported via the
MID: Start Result
variable.
NXP Semiconductors
Remote control using FreeMASTER
MCUXpresso SDK Field-Oriented Control (FOC) of 3-Phase PMSM and BLDC motors, Rev. 0, 01/2022
User Guide
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