WOLFRAM SYSTEM MODELER

# AronSensor

Three-phase Aron sensor for active power

# Wolfram Language

In[1]:=
`SystemModel["Modelica.Electrical.Polyphase.Sensors.AronSensor"]`
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# Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

Contains two power meters to measure total active power in a three-phase system.

This device works only in three-phase systems without neutral.

The rationale behind this sensor is that power exchanged between two parts of a circuit is the sum of the products of currents in the m wires connecting the two parts times wires' potentials evaluated with reference to an arbitrary potential vref:

P=(v1-vref)*i1+(v2-vref)*i2+…+(vm-vref)*im

In case of a three-phase system without neutral we may want to measure power flowing in a line, connecting, say, the left part of the circuit to its right part. The wires connecting the two parts are only three (i.e., m=3) and therefore all currents between these two parts are i1, i2, i3

Since the voltage to be taken as reference is arbitrary, we can take the voltage of conductor 2. Therefore our power becomes:

P=(v1-v2)*i1+(v2-v2)*i2+(v3-v2)*i3 = (v1-v2)*i1+(v3-v2)* i3

In this way, we can just sum up the power from two wattmeters to get the three-phase power.

Note, that this formula does not work if there are additional current paths between the left and right parts of our circuits, e.g., if both have grounds (and current flows through it).

For more information on why power flowing in a circuit between two subcircuits is the sum of products of voltages times currents, the voltages being measured to an arbitrary reference potential, see [Ceraolo2014, par. 3.8.1].

# Parameters (1)

m Value: 3 Type: Integer Description: Number of phases

# Connectors (3)

plug_p Type: PositivePlug Description: Positive polyphase electrical plug with m pins Type: NegativePlug Description: Negative polyphase electrical plug with m pins Type: RealOutput Description: Active power

# Components (5)

plugToPins_p Type: PlugToPins_p Description: Connect all (positive) Pins Type: PlugToPins_n Description: Connect all (negative) Pins Type: PowerSensor Description: Sensor to measure the power Type: PowerSensor Description: Sensor to measure the power Type: Add Description: Output the sum of the two inputs

# Used in Examples (2)

 Rectifier Modelica.Electrical.Polyphase.Examples Test example with polyphase components TestSensors Modelica.Electrical.Polyphase.Examples