Mains Failure Control - Lenze i55AE125B Manual

11.15

Mains failure control

In case of power failure, this function can decelerate the motor and use its rotational energy
to maintain the DC-bus voltage for a certain period of time. This makes it possible to continue
to let the motor run during a short-term failure of the mains voltage. After mains recovery, the
operating status that was active before the failure is adopted again.
Details
A failure of the mains voltage causes a continuous DC-bus voltage drop. If the mains failure
control is enabled in 0x2D66:001
the activation threshold set in
As soon as the mains failure control is active, the motor is decelerated. Now the rotational
energy of the motor is used to maintain the DC-bus voltage above the error threshold for
undervoltage until the motor is decelerated to standstill in a controlled way. This process is
controlled by the DC-bus voltage controller.
Trigger
Current DC-bus voltage
①
Frequency setpoint (internal input signal)
②
Frequency setpoint (internal output signal for motor control)
③
The activation and commissioning of the mains failure control are described in detail in the
following subchapters.
Parameter Name / value range / [default setting]
0x2D66:001 Mains failure control: Enable function
(P721.01) (Mains fail. ctrl: Enable function)
• From version 02.00
0 Disabled
1 Enabled
0x2D66:002 Mains failure control: DC-bus activation level
(P721.02) (Mains fail. ctrl: DC-bus act.level)
60 ... [0]* ... 90 %
* Default setting depending on the size.
• From version 02.00
0x2D66:003 Mains failure control: Gain V-controller
(P721.03) (Mains fail. ctrl: Gain V-ctrl)
0.00001 ... [0.01000] ... 0.50000 Hz/V
• From version 02.00
0x2D66:004 Mains failure control: Reset time V-controller
(P721.04) (Mains fail. ctrl: Res. time V-ctrl)
5 ... [20] ... 2000 ms
• From version 02.00
(P721.01), it will get active if the DC-bus voltage falls below
0x2D66:002 (P721.02).
Mains failure control
0x2D66:001 Enable function
0x2D66:002 DC-bus activation level
0x2D66:007 Clear time
0x2D66:008 Restart threshold
Reset
0x2631:004
0x2D66:005
0x2D66:006 0x2D66:003
0x2D66:004
Additional functions
Status 0x2D66:009
1
0
Info
1 = enable mains failure control.
Threshold below which the mains failure control is activated if it is ena-
bled (0x2D66:001 (P721.01) = 1).
• 100 % ≡ nominal DC-bus voltage
Recommended setting:
• In general: 5 ... 10 % above the error threshold for undervoltage (dis-
play in 0x2540:003 (P208.03)).
• 230-V devices: 72 %
• 400/480-V devices: 82 %
Proportional gain of the DC-bus voltage controller.
Reset time of the DC-bus voltage controller.
Mains failure control
485