Pole Position Identification Without Movement - Lenze i55AE125B Manual

8.3.6

Pole position identification without movement

If a permanent-magnet synchronous motor is driven by the inverter, a "pole position identifi-
cation (PLI)" is required for an optimum and jerk-free starting torque. In the default setting, a
pole position identification is executed after each inverter enable. If the pole position identifi-
cation is deactivated, the motor may briefly rotate backwards before starting or stall if the
starting torque is too high.
NOTICE
With an incorrect parameter setting and dimensioning of the inverter, the maximum permissi-
ble motor current may be exceeded during the pole position identification.
Possible consequence: irreversible damage of the motor.
▶ Set the motor data correctly.
▶ Only use an inverter that is performance-matched to the motor.
Preconditions
The wiring of the three motor phases and the motor encoder must be carried out accord-
•
ing to the specifications from the mounting instructions.
The inverter is ready for operation (no fault active).
•
For the pole position identification (PPI) without movement, the motor must be at stand-
•
still. In order that the pole position identification is only executed at standstill, set the start
method "Flying restart circuit [2]" in
Details
This function was developed for a wide range of motor characteristics. In case of some motor
types, the identified pole position may differ considerably from the real pole position, so that
a considerable loss in torque and greater motor losses may occur.
The pole position identification can be executed automatically after every inverter enable if
"After each enable [2]" is selected in 0x2C63:001. Further settings are not required for this
function.
Process of the pole position identification:
1. After inverter enable, a defined pulse pattern is output that provides currents up to
approx. maximum motor current. The respective currents are measured. Based on these
currents, the field distribution can be detected so that the pole position can be calculated.
This process lasts maximally 1.8 seconds.
2. After the pole position identification has been carried out successfully, the motor follows
the setpoint selection.
During the pole position identification:
The current test pulses cause audible engine noises that may be increased by the machine
•
mechanics depending on the mechanical coupling!
The function can be aborted by the inverter disable any time without changing the set-
•
tings. In this case, you have to carry out the pole position identification again.
If the function is aborted by itself, the motor features may not be suitable for this function.
•
If an error occurs during the pole position identification,
the procedure is stopped without the settings being changed.
•
the response set in 0x2C60
•
Parameter Name / value range / [default setting]
0x2C60 PPI monitoring: Reaction
• From version 04.00
• For further possible settings, see parameter
0x2D45:001
3 Fault
4Motor data
^ 164
0x2838:001 (P203.01).
is effected.
(P310.01).
^ 223
Pole position identification without movement
Info
Selection of the response triggered by the occurrence of an error during
the pole position identification (PLI).
Associated error code:
28961 | 0x7121 - Pole position identification fault
•
Motor control
Optimisation of motor control
191