Danfoss VLT Active Front End AFE 302, Руководство по эксплуатации

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3.9 Start-up Sequence
Illustration 3.19 shows the typical AFE start-up sequence flow chart. The flow chart describes the interaction among Auxiliary
Hardware, AFE Frequency Converters, and Liebherr Control PLC. The arrowed lines indicate the flow of the actions. The
Liebherr PLC expects to receive the “Control Ready” and “Ready” signals from the AFE frequency converter and it will send
“Run” signal to AFE frequency converter. The waiting periods and the number of tries are tentative. The “Control Ready”
signal is on when the power in Control Card is on. The meaning of the "Ready" signal in the AFE frequency converter is
different from the one in the standard frequency converter. The “Ready” signal in the AFE frequency converter is on when
the DC voltage is boosted to the level where the AFE regulation is enabled.
Auxiliary Hardware
Actions AFE Drive Control PLC
: Assume that the AFE contactors
and SC contactor are open
prior to this start-up sequence.
Start-up Sequence
Crane ON
Contactor LCL cabs ON
2 sec Delay
Send close signal to
the SC contactor.
Receive "Soft Charge
Ready" signal within
20sec?
Protection Mode
due to the Start-up
Failure
No
Wait for 1 second
to have the DC capacitors
charged further.
Yes
Send the open signal
to the SC contactor.
Wait for 1 second
to make sure that the
S/C contactor is open.
Send the close signal
to the AFE contactors.
Wait for 0.5 second
to have the DC capacitors
charged fully.
Send the "Run"
signal to the AFE drive.
Receive "DC-Link
on Ref" signal from
AFE within 5 sec?
End of Start-up
Sequence
No
No
Yes
Yes
Protection Mode
due to the Start-up
Failure
3rd Try?
:The waiting period can be substituted
by the contactor status signal.
: Assume that the AFE contactors
are fully engaged within 2seconds.
:The waiting period can be substituted
by the contactor status signal.
: Assume that the SC contactor is
disengaged within 0.5sec.
The DC capacitor discharge
is negligble.
130BA783.12
Abbreviations:
AFE: ACtive Front End
CC: Control Card
PC: Power Card
PLC: Programmable Logic Controller
SC: Soft Charge
When the DC voltage is within
the target range, "DC-link on
Ref" signal is on.
The AFE drive is active.
DC voltage is going
up to the desired level.
The AFE contactors
are closed.
The SC contactor
is open.
Charge the DC bus
through the SC circuit.
The SC contactor
is closed.
When the PC becomes
active, "Soft Charge Ready"
signal is ON.
Illustration 3.19 Start-up Sequence Flow Chart
Crane System Design Operating Instructions
MG33X402 Danfoss A/S © Rev. 05/2014 All rights reserved. 21
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