Commissioning Cos Phi Display - Siemens SINAMICS S120 System Manual

Commissioning

7.9 Commissioning cos phi display

7.9 Commissioning cos phi display
Preconditions
● For the cosφ calculation function, when commissioning, the Active Line Module function
module "Supplementary module cosinus phi" must be activated. This means that
additional parameters p3473 to p3479 are available.
If a second VSM10 is to be used to display cosφ, then the grid transformer function
module should also be activated.
● Precondition for a correct cosφ display, is that the Active Line Module and the Voltage
Sensing Module operate on the same grid, i.e. with the same grid frequency. It is
especially important that parameter r0066 indicates the correct grid frequency and that
the Active Line Module is operational. Transformers can be used between the measuring
point and the connection point of the Active Line Module; a possibly associated phase
shift (interchanged phase sequence) must be parameterized (see p3475).
● Phase currents and conductor voltages at the measuring point are the input variables for
the cosφ display.
– Measured values (i1, i2, u12, u23) can be sensed using various devices and fed to the
– The VSM10 with 2 measuring inputs for grid voltages up to 3 AC 690 V
– In principle, currents or voltages can also be used from the grid model of the Active
Application
● cosφ values for two different connection points at the same grid can be simultaneously
sensed and calculated (e.g. an outer cosφ at the connection point of the complete system
with the grid, and an inner cosφ at the inverter terminals). This is the reason that the
parameters are indexed 2x.
● Using p3475, two independent cosφ displays can be activated (bit 0) and configured.
– Configuration bit 1 defines whether the input signals for voltage and current are
– Configuration bit 2 defines whether between the cosφ measuring point (voltages,
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calculation block through a BiCo link (p3473, p3474). Possible deadtimes as a result
of signal transfer times/propagation times should be taken into account (see
"Calibration parameter p3479" in Section, Application).
voltage transformers for +/-10 V are suitable for sensing values. Suitable current
transformers must be selected and the conversion into current magnitude (p3670)
parameterized on an application-for-application basis.
Line Module control (r3467, r3468) for the cosφ display. However, the unavoidable
component statistical scatter (especially of the grid filter) can result in a lower display
accuracy.
present in space vector coordinates (alpha/beta) – or in a 3-conductor representation
(phases R, S, T). As a consequence, signals can be used from internal grid models
(e.g. r3467, r3468) – or also direct VSM10 measured values (e.g. r5461, r5471).
currents) and the terminals of the Active Line Module, the phase sequence has been
interchanged as a result of a transformer.
and current-
rms
System Manual, 04/2015, A5E03347436A
Grid infeed