3TX20-19
ADJUSTINGPROCEDURE FOR PARALLELOPERATION WITH VOLTA-
GEDROOP
Step 1
Adjust the drooppotmeters D to middle position. Adjust the regula-
tors of all generators in single operation. Take care for good regu-
lation behaviour at all possible load conditions.
Step 2
Adjust the generatorvoltage of all generators to exactly the same
value at no-load. This must be done in single operation. The voltage
should preferably be measured with the same instrument at all
generators.
Step 3
Switch generators parallel and adjust the load (in kW) with the
driving engine to the same value for all generators. If the generators
are not equal sized, the load must be divided corresponding to
ratio. After this the generatorcurrent must be equal (or divided to
ratio) at all load conditions. When this is not the case it may be
adjusted with the drooppotmeter. In no case it may be adjusted with
the potmeters for voltage adjustment.
Note:
The droopkit makes the generatorvoltage dependend of the
loadcurrent and the powerfactor. The generatorvoltage
should decrease at increasing load with an inductive
powerfactor less or equal then one. If it is the other way
around, the secondary connections of the drooptransformer
should be changed.
Installation of droopkit
The droopkit consists of a drooptransformer, which is basically a
special designed currenttransformer. The drooptransformer must be
placed in the generators main current according to the connecting
diagrams of our regulators. The maximum current of the drooptrans-
former (see tag plate) must be equal or more then the generator
m aximum current. If the generator main current is much less then
the drooptransformers current, the generator cable must be led
through the drooptransformer twice or more. Be sure that the
amount of windings multiplied with the generatorcurrent does not
exceed the maximum current of the drooptransformer must be
3TX20-20
installed separately according to the diagrams.
Troubleshooting during commisioning paralleloperation
-Paralleloperation does no work properly
Check
-
connections of the voltage regulator and the drooptrans-
former according the correct diagram
-
direction of the drooptransformer
-
clockwise rotation of the generators main voltage
-
the current through the drooptransformer. The current
must as much as possible of the phasecurrent.
-
voltages of the generators in no load conditions. These
voltages must be equal.
-
the stability of the engines and the load sharing of the
engines
In all cases where you are not able to solve the problem with this
help, we advise you to contact an expert or let the gener a t o r c h e c k
in an electrical repair workshop.
Troubleshooting during commisioning
-Generator does not give voltage at all
Check
-
connections of the avr
-
rotating speed of the generator
-
windings of the generator for shortcircuits to earth on
fields, exciters, rotor and stator
-
windings of the generator for shortcircuits between phases
-
windings of the generator for shortcircuits on fields,
exciters, rotor and stator
-
lose connections of fields, exciters, rotor and stator
-
rectifiers on the rotor or from compound systems
-
load which is already switched on
-
excitate the generator according the field flash diagram
-Generatorvoltage remains low and is not adjustable
Check
-
connections of the avr
-
rotating speed of the generator
