8400 StateLine, HighLine and TopLine: FW version ≤ 13.00.00.00
What happens?
When the speed controller parameters Vp and Ti are not changed, instabilities with regard to the control show after an increase of the reference speed C011.
When does the problem occur?
If, with the same motor parameter settings, C011 is changed so that the first result is a reference frequency C059<650Hz and the second result is a reference frequency C059≥650Hz. For these two configurations, the internal resolution of the frequency differentiates (20mHz resolution up to C059=649.99Hz and 40mHz resolution from C059=650.00Hz). When the speed controller parameters Vp and Ti are scaled, this change-over is not taken into consideration in the frequency resolution.
The restriction only occurs in the SLVC and SLPSM motor control types (C006=3+4).
Diagnostics options?
Recording of the speed controller output nOutputSpeedCtrl_a by means of the Engineer oscilloscope or PCAN if C011 varies.
Short-term measures/recommendations?
None.
Evaluation:
C011 or the motor parameters which produce a change-over in the frequency resolution are typically only altered during the configuration and commissioning.
Only then the response has an effect. For both resolutions of the output frequency, stable speed controller parameters can be set.
