KEB COMBIVERT F5 BASIC Applications Manual page 236

Functional Description
Emergency stop with braking
module
Emergency stop without braking
module
Chapter Section Page
6 9 24
back only the energy which the inverter requires for operation. The starting voltage is at
the same time the setpoint value for the DC-link control. The control value is the setpoint
value of the slip control.
In case of weak supply systems it is recommended to select the automatic starting
voltage, since in this case the starting voltage value is adapted to slow voltage
fluctuations.
Restart at power recovery
In mode 0 the power recovery is constantly detected and in mode 2 up to reaching the
restart threshold. An immediate restart upon power recovery is possible.
After detecting the power recovery the restart delay (Pn.52) runs down and the drive
accelerates to the current setpoint value.
Behaviour below the restart threshold
• Setpoint value = starting voltage (Pn.44 Bit 6-7 = 0):
An immediate restart is not executed below the restart threshold (Pn.48). The
drive decelerates with the fast-stop function (Pn.58..60) and then behaves
according to the adjustment in Pn.44 Bit 3-4.
• Increase voltage setpoint value (Pn.44 Bit 6-7 = 2):
In order to have more energy to slow down the flywheel masses when the minimum
output value is reached, the voltage setpoint value can be raised to the voltage
setpoint value Pn.50 (Pn.44 Bit 6-7 = 2) should it fall below the restart threshold.
In this case the control remains active with the increased setpoint value. At
small speeds the drive supplies no more energy. For operation without speed
detection the control must be very smooth in this range to prevent stalling.
Below the restart value the control parameters of the active current control are
lowered linearly with the output frequency.
Set value source:
Braking torque Pn.47 (Pn.44 Bit 6-7 = 3)
In this mode the drive is to be stopped as fast as possible. As the refed energy can be
very high, a braking resistor is necessary.
The DC-link voltage controller is not active. The drive decelerates with the quick-stop
function Pn.60..61 (see Chapt. 6.7.7) and behaves then in accordance with the setting
in Pn.44 Bit 3-4.
At small speeds the drive supplies no more energy. For operation without speed
detection (active current control) the control must be very smooth in this range to
prevent stalling. It is possible to adjust the restart value (Pn.48). Below the restart
value the control parameters of the active current control are lowered linearly with the
output frequency.
Set value source:
Increased voltage setpoint value Pn.50 (Pn.44 Bit 6-7 = 1)
In some cases one can do without a braking module with the Emergency-Stop function,
if the losses in the motor are very high at high DC-link voltage.
The voltage stabilisation should be switched off in this case. This can be done with
Pn.44 Bit 8 = 1 during Power-Off.
The DC-link voltage control is active. It is always decelerated onto the minimum output
value. Accordingly the performance results from the adjustment of Pn.44 Bit 3-4.
Date Name: Basis
18.04.02 KEB COMBIVERT F5
Special Functions
© KEB Antriebstechnik, 2002
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