• The nominal voltage of the busbar (BB) is 10 kV.
Because the generator’s nominal voltage is 400 V, there is no need for a measurement transformer on the LV side in this example.
The ML-2 can handle up to 690 V. But it is still required to set up current transformers on the LV side. In this example, the current
transformers have a nominal current of 300/5 A.
Due to the fact that the step-up transformer is a Dz4, there will be a phase angle twist of -120 °.
These settings can be programmed via the display or the utility software. These settings must be put into the parameters shown in
the table below:
Parameter Comment Setting
6002 Generator nominal power 140
6003 Generator nominal current 250
6004 Generator nominal voltage 400
6041 LV measurement transformer primary side (There is none here) 400
6042 LV measurement transformer secondary side (There is none here) 400
6043 Current transformer primary side 300
6044 Current transformer secondary side 5
6051 HV (BB) measurement transformer primary side 10000
6052 HV (BB) measurement transformer secondary side 100
6053 Nominal HV setting of step-up transformer 10000
9141 Phase angle compensation 120 °
INFO
The ML-2 controller can directly handle voltage levels between 100 and 690 V. If the voltage level in the application is
higher or lower, it is required to use measurement transformers that transform the voltage into a number between 100 and
690 V.
6.44.4 Vector group for step-down transformer
In some applications, there may also be a step-down transformer. This could be to transform a grid voltage down, so the load can
handle the voltage level. The controller is able to synchronise the busbar with the mains, even if there is a step-down transformer
with a phase angle twist. The transformer must be between the measuring points for the controller. If a step-down transformer is
used, these settings must be set in parameter 9141 to compensate the phase angle twist.
Vector group
Step-up transformer types Parameter 9141
0 Yy0, Dd0, Dz0 0 °
1 Yd1, Dy1, Yz1 -30 °
2 Dd2, Dz2 -60 °
4 Dd4, Dz4 -120 °
5 Yd5, Dy5, Yz5 -150 °
6 Yy6, Dd6, Dz6 180 °
7 Yd7, Dy7, Yz7 150 °
8 Dd8, Dz8 120 °
10 Dd10, Dz10 60 °
11 Yd11, Dy11, Yz11 30 °
DESIGNER'S HANDBOOK 4189341275A EN Page 175 of 196
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