Dc Component Controller; Supplementary Functions; Grid Voltage Sensing Using An Additional Vsm10 - Siemens SINAMICS S120 System Manual

6.2.4

DC component controller

Application
Regarding the background information, please refer to the section on the DC component
control in current-controlled operation, see DC component controller (Page 52).
Contrary to this, the DC component control in the grid controlled operation is generally
mandatory, especially if the island grid contains transformers. (In current-controlled
operation, the basic frequency current control already ensures adequate compensation of
the DC component)
The controller is automatically preset. A transformer with typical data and a power rating
approximately the same as the Active Interface Module is assumed. If this assumption does
not apply, then the main transformer inductance p5492, total resistance p5436 and controller
integration time p5437 must be appropriately set (also refer to the parameter descriptions). If
data sheet data is not available, the magnetizing inductance can be measured using an
identification run. Please refer to the section on the DC component control in current-
controlled operation.
Note
Unsuitable settings of this DC component controller (especially excessively high control gain
p5436) can result in instability of the complete grid control.
6.3

Supplementary functions

6.3.1

Grid voltage sensing using an additional VSM10

Additional voltage measured values are required for many applications in the area of forming
island grids, corresponding to the "Grid control" diagram. The "Grid transformer" function
module supports the evaluation of up to 2 additional VSM10 devices.
Voltages u12/u23 are detected by the VSM10 included as standard for Active Interface
modules, chassis format. In the case of a parallel ALM/AIM circuit, it should be noted that
each of these parallel components includes a VSM10; an average measured value is
calculated and is considered here as a single, effective VSM10. The administration
parameters are available from p0140ff. (For power generating applications using Active Line
Modules, booksize format, a VSM10 connected to the Active Interface Module is specified.)
When the "Transformer magnetization" function is used, voltages u12
sensed using an additional VSM10. We recommend that this VSM10 is used for the grid
droop control, in order to guarantee that the droop characteristics are precisely maintained.
When required, instead of this, the voltages can be also calculated using the transformer
model (r5498).
However, errors in the model parameters then automatically result in incorrect voltage values
and deviations in the power distribution in the island grid involving several power generating
units.
Grid infeed
System Manual, 04/2015, A5E03347436A
Detailed descriptions of the function modules
6.3 Supplementary functions
/u23
isl
must be
isl
63