Motor variables
Next variables are located in the folder /driver/motor.
VECTOR vs BLDC
All these parameters are present in both the VECTOR and BLDC motor control algorithms. However, BLDC algorithm uses only a pp parameter. Other parameters are there only for the embedded identification procedures (identlin, identrun, ...). Therefore, changing their values will not affect motor control performance.
Parameters
The parameters hereby shall define the motor connected to the controller. In some scenarios, the properly identified motor parameters are crucial for correct driver operation (e.g. sensorless mode in vector drive).
All the motor parametres are automatically identified with the identrun and identlin procedure, no need to set it manually.
pp [pairs]
Number of motor pole pairs. This parameter is primarily required for correct speed computation.
- Motor with 4 poles -> 2 pole-pairs. Set pp = 2.
- To get number of poles of a typical motor construction, count the rotor magnets.
Need to be set manually.
psi [Wb]
The permanent magnet motor flux linkage. This parameter defines the main motor (synchronous machine) constant (the relation between voltage and speed as well as between the current and the torque).
To derive the KV constant, use the following formula:
Special values:
| Value | Description |
|---|---|
| 0 | ACIM - AC induction machine |
| 1e-10 | synRM - synchronous reluctance motor |
Rt [ohm]
Phase resisistance in the star model. This parameter reflects the phase-to-phase resistance divided by two. Note that the internal controller resistance as well as the resistance of the phase wires should be included.
Ld [Hennry]
D-axis phase inductance in the star model. This parameter reflects the phase-to-phase inductance divided by two, measured at zero current and when the rotor is positioned such that the stator teeth are aligned with the rotor teeth.
Lq [Hennry]
Q-axis phase inductance in the star model. This parameter reflects the phase-to-phase inductance divided by two, measured at zero current and when the rotor is positioned such that the stator teeth are in between the rotor teeth.
Dp [1/degC]
PM flux temperature hyperbolic derating in units per degree celsius.
Dt [1/degC]
Resistance temperature hyperbolic derating in units per degree celsius.
Da [1/Amp]
Aligned inductance hyperbolic derating in units per ampere.
identlin procedure attempts to identify this parameter only when '-n' option is specified.
Dc [1/Amp]
Cross inductance hyperbolic derating in units per ampere.
identlin procedure attempts to identify this parameter only when '-n' option is specified.
State variables
Variables ended with "f" are filtered using the filter constants /driver/Kf and /driver/Kr.
odo [rev]
Motor mechanical revolutions since controller start. Note that the application may reset the accumulator.
voltageq [V]
voltageon BLDC
Actual value of phase voltage in Q axis (torque creating axis).
voltaged [V]
Actual value of phase voltage in D axis.
To get the actual total stator voltage (DC-side equivalent voltages), use this formula:
currentq [A]
currenton BLDC
Actual value of motor phase curent in Q axis (torque creating axis).
currentd [A]
Actual value of motor phase curent in D axis.
voltageqf [V]
Actual value of phase voltage in Q axis, filtered.
currentqf [A]
Actual value of motor phase curent in Q axis, filtered.
To get the actual total stator current, use this formula:
rpmf [rpm]
Mechanical speed of the rotor shaft. Make sure that the motor pole-pair count 'pp' is set corectly.
Rthermistor [ohm]
Resistance of the thermistor connected to MTEMP input (typicaly, the motor temperature sensor)
Vthermistor [V]
Voltage reading of the MTEMP input.
mres [ohm]
Winding estimated resistance. This value is only obtained when there is flowing some current through the motor.
BLDC states
duty [%]
Actual motor PWM duty cycle.