Corrected from:
9400 HighLine firmware version 12.00.18.00
9400 Servo PLC firmware version 06.00.18.00
Response of the new version:
Even if MOL is activated, the pole position will be identified correctly.
Which products are concerned? 9400 HighLine: 07.00.30.00 ≥ firmware version ≤ 11.00.10.00
9400 Servo PLC: 02.01.14.00 ≥ firmware version ≤ 05.00.10.00
What happens?
With synchronous motor control, typical indicators of an incorrectly set pole position are detected:
- Increased current consumption
- Different current consumption under identical load depending on the direction of rotation. As a result, the indicated torque which is calculated from the current is not correct either.
- The motor accelerates in an unpredictable direction of rotation up to a speed exclusively determined by the voltage limitation and remains at this speed.
When does the problem occur? The behaviour occurs after execution of a pole position identification (PPI) over 360 ° (electrically) in which the basic function LS_ManualJogOpenLoop (bEnable = TRUE) had been requested simultaneously. An identification run over 360 ° (electrically) can be executed by means of the device command C00002 = 51 or, alternatively, by means of the basic function LS_PolePositionIdentification with the setting C02786 = 0. The identification run with minimum movement (C00002 = 52 or C02786 = 1) detects the faulty pole position identification and cancels the identification with the status C00003 = 3447597 'Identification of pole position cannot be executed because the rotor has moved too strongly'. In this case, the error response parameterised in C640 (Resp. to pole pos. id. monit.) will be triggered.
Possible diagnostics: Due to the above defect, the identified pole position is always exactly 0.0 °. If the pole position identification works correctly, this is usually not the case. The identified pole position is indicated in C058/1 for resolver feedback or in C058/2 for encoder feedback.
Short-term measures/recommendations: Set LS_ManualJogOpenLoop.bEnable to FALSE before starting the pole position identification.
Assessment: In the worst case, a synchronous motor may accelerate up to a speed at the voltage limit when operated with an incorrect pole position. Monitoring modes with 'Quick stop by trouble' response cannot stop the motor. A pole position identification is only required when using a synchronous motor of a third-party manufacturer. Requesting the basic function LS_ManualJogOpenLoop in parallel to the execution of a pole position identification is very unusual.
Final solution: Correction of the pole position identification in the next FW release.
