Reference Handling; Dc Reference Tuning - Danfoss Vacon NXP Applications Manual

60 · vacon
5.2

Reference handling

2.2.1 DC Voltage Reference ID1462
This parameter sets the DC Voltage reference in % of the Nominal DC voltage.
If P2.1.5 System Nominal DC is zero then
Nominal DC voltage = 1.35 * Grid Nom. Voltage (P2.1.1).
Final DC Voltage Ref (V1.1.2) = Nominal DC Voltage * DC Voltage Reference
The DC Voltage will be maintained at this level when the regenerative unit is running.
There is internal limitation to reference: For 500V units the maximum limit is 797 Vdc
and for 690V units the maximum limit 1099 Vdc.
The maximum limit can be monitored from V1.1.15 DC Ref Max Lim.
NOTE! If DC voltage exceeds the values below in STOP state, the drive will lose READY
state:
• 797 Vdc for 500V unit, trip limit 911 Vdc
• 1099 Vdc for 690V unit, immediate trip limit 1200 Vdc, U2t protection above 1100 Vdc.
• 1136 Vdc for LC 690V voltage class 8 (Order code example: NXA15008_ _ _ _ _W)
NOTE! When transformer ration is different than 1:1 also P2.1.7 System Nominal DC
parameter must be given so that MCB is closed at correct voltage level and AFE mode
DC Voltage reference is giving correct DC-Link Voltage.
By default the internal DC voltage reference is kept the same as the actual DC voltage
when the drive is in STOP state, or the operation mode is Island or Micro Grid. This is to
make the change to the AFE mode smoother when the change is done on the fly.
2.2.2 Reactive Current Reference
This parameter sets the reference for the reactive current in % of the nominal current.
This can be used for power factor correction of AFE system or reactive power
compensation. Positive value gives inductive compensation whereas negative value gives
capacitive compensation.
In uGrid mode 100.0 % reactive reference will decrease voltage by set voltage drooping
value.
NOTE: Reactive Current reference does not affect voltage in island mode operation.
5.2.1

DC Reference Tuning

2.2.3.1 DC Drooping
When AFEs are used in parallel in independent mode, drooping can be used for current
balancing. The DCV voltage reference drooping is set as % of the active current
reference.
5
ID1459
ID620
Tel. +358 (0)201 2121 • Fax: +358 (0)201 2121 205
Description of parameters