There are a variety of setting options for power failure bridging in closed-loop controlled mode.
Setting: P 02949 SRLWR(1) and SRLOR(2)
Addition of P 2944 (software shut-off limit) and
P 2942(1) = voltage reference value.
The resultant voltages must not be greater than the detection limit.
Setting:P 2940 = SRLWOR(3):
Addition of P 2945 (brake chopper switch-on threshold) and P 2942(1) (voltage reference value).
The voltage must not fall below 95% of the brake chopper switch-on threshold.
If the mains power is restored within this time, in speed control a restart is effected with the parameterized speed ramp from the profile generator.
In position-controlled mode the speed is run down to zero with the preset quick-stop ramp.
If the mains power is not restored within the preset time, an error message is generated. The system reacts according to the error reaction (Fault 34 Reac_PowerFail).
Parameters
| P. no. | Parameter name | Function |
|---|---|---|
| P2940 | CON_PowerFail | Selector |
| (0) | Off(0) | No function |
| (1) | SRLWR(1) | Longest possible speed reduction with restart |
| (2) | SRLWOR(2) | Longest possible speed reduction without restart |
| (3) | SRLWOR(3) | Fastest possible speed reduction without restart. |
| P2941 | CON_POWF_VCtrl | Voltage controller changeable online |
| (0) | Kr | Gain factor of PI voltage controller |
| (1) | Tn | Integral-action time of PI voltage controller |
| P2942 | CON_POWF_VLim | Voltage limit in case of power failure |
| (0) | POWF_Von | Power failure detection limit |
| (1) | POWF_VRef | Voltage reference value |
| P2943 | CON_POWF_RetTime | Setting of time window in which mains power can be restored |
| P2944 | CON_POWF_UdcOff | Software shut-off limit for detection of DC link undervoltage |
| P2945 | CON_POWF_UbcOn | Brake chopper switch-on threshold |
Tabelle: Mode selector for speed reduction
Power failure bridging
Copyright © LTi DRiVES GmbH, Januar 2013, ID-Nr.: 0842.26B.1-00 DE