Why are there no single phase quasistatic RMS voltage and current sensors?

[mestinso]

The multiphase quasistatic electrical library includes RMS sensors, however they are absent from the single phase quasistatic sensors. I would comment they are generally useful for me and I don't see a good reason why they shouldn't be included. Am I missing anything?

[AHaumer]

Well, you're welcome to propose an implementation / pull request ...

[mestinso]

@AHaumer Sure, will plan on it. I wanted to makes sure I wasn't missing something first. Thanks.

[christiankral]

Referring to MSL 4.0.0:

The single-phase sensor Modelica.Electrical.QuasiStatic.SinglePhase.Sensors.CurrentSensor senses the RMS complex current which is equal to the magnitude of the current i flowing through the sensor.

The polyphase sensor Modelica.Electrical.QuasiStatic.Polyphase.Sensors.CurrentSensor senses m RMS complex currents, each of them calculated as the magnitude of determine the phase currents i[:]. In case of a fully symmetrical polyphase system, all the currents i[:] are equal to each other.

There is, however, the additional sensor Modelica.Electrical.QuasiStatic.Polyphase.Sensors.CurrentQuasiRMSSensor which calculates the quadratic average phase currents, named as "quasi RMS current":

y = sum({sqrt(i[k].re^2 + i[k].im^2) for k in 1:m})/m

In case of a fully symmetrical polyphase system the quasi RMS current y is equal to each of the phase currents i[:].

From my understanding the desired sensors already exist.

[mestinso]

@christiankral Which component are you specifically referring to when you say the desired sensor already exists? The output of Modelica.Electrical.QuasiStatic.SinglePhase.Sensors.CurrentSensor is a complex value (not desired). Also, while the math inside Modelica.Electrical.QuasiStatic.Polyphase.Sensors.CurrentQuasiRMSSensor is what i want for m=1, the ports aren't compatible with single phase and the following underlying component doesn't like m=1: Modelica.Electrical.QuasiStatic.Polyphase.Blocks.QuasiRMS.

[christiankral]

OK, now I understand what you mean.

You are right, the output is always a complex quantity. In the current implementation one has to use the block Modelica.ComplexBlocks.ComplexMath.ComplexToPolar to determine the magnitude (RMS value) of a single-phase current.

So please provide a pull request with additional sensors:

• Modelica.Electrical.QuasiStatic.SinglePhase.Sensors.CurrentRMSSensor
• Modelica.Electrical.QuasiStatic.SinglePhase.Sensors.VoltageRMSSensor