Symbol of the source with impedance

Description

The impedance source is implemented as a three-phase network element. The model is a Norton equivalent that directly interfaces with network elements.

Table of Contents

Model equations

The equations below describe the impedance source:

Where

are the internal voltages of the source for phases a, b, and c, respectively.

are the resistances, mutual inductances, and self-inductances of the voltage source for i = a, b, c and j = a, b, c.

The internal voltages of the source are obtained automatically if the source participates in the load flow or are input by the user.

The resistances, mutual inductances, and self-inductances of the voltage source are obtained or calculated based on the selected Input Mode:

If Input Mode is Matrix: The user provides the source impedance matrix.
If Input Mode is Sequences: The user provides the positive and zero sequence impedances. The resistances, mutual inductances, and self-inductances are then calculated as follows:

Input Mode is ShortCircuit data. The user provides the three-phase and single-phase short-circuit powers, as well as the ratios between reactance and resistance for the positive and zero sequences. The resistances and reactances in the positive and zero sequences are then calculated as follows:

Where is the ratio between reactance and resistance of the positive sequence.

The zero-sequence resistance is calculated by solving the second-order equation below:

Where

And is the ratio between the reactance and the resistance of the zero sequence.

If this equation does not yield any real roots, and the resistance is obtained as follows:

Participation of the model in the load-flow solution

The impedance source participates in the load flow.

Mask and Parameters

The source with impedance form has three tabs:

General: contains the general parameters of the source.
Impedance: defines the source impedance.
Load Flow: defines the initial conditions of the source.

Below are each tab's figures, the variables' tables, and their definitions.

General

Name	Description	Unit

Name	Description	Unit
Base Power	Rated power	kVA
Base Voltage	Rated voltage (line-to-line)	kV
Frequency	Rated frequency	Hz
Connection	Winding connection	-
Amplitude	Amplitude (RMS phase-to-ground) of each phase	Ohm
Angle	Angle of each phase	Ohm

Impedance

Name	Description	Unit

Name	Description	Unit
Input Mode	The impedance of the source can be chosen as follows: Impedance in matrix form Impedance in positive and zero sequence form Short-circuit powers, and resistance and reactance ratios
R- matrix mode	Resistance in matrix form	Ohm
L-matrix mode	Inductance sous forme matricielle	Henry
R-sequence	Inductance in matrix form	Ohm
L-sequence	Positive and zero-sequence inductance	Henry
S3cc-3 phase short-circuit power	Three-phase short-circuit power	W
S1cc-1 phase short-circuit power	Single-phase short-circuit power	W
X1R1-Ratio positive resistance and reactance	Ratio between resistance and reactance of the positive sequence	-
X0R0-Ratio homopolaire resistance and reactance	Ratio between resistance and reactance of the positive sequence	-

Load Flow

Name	Description	Unit

Name	Description	Unit
Type of bus	The bus can be: Swing PV PQ	-
Voltage	The desired voltage at the terminals of the source	pu
Angle	The desired voltage angle at the terminals of the source	deg
Active power	The active power delivered by the source	MW
Reactive power	The reactive power delivered by the source	MVAr
Reactive power minimum	The minimum reactive power that the source must deliver	MVAr
Reactive power maximum	The maximum reactive power that the source must deliver	MVAr

Ports, Inputs, Outputs and Signals Available for Monitoring

The figure above shows the symbol of the impedance source model in the Network Sources category of the HYPERSIM model library. This model has four pins:

Three-phase pin (+)
Single-phase neutral pin

Ports

This model has four pins:

Net_S: Three-phase pin (+), Network connector on the AC side. It supports a three-phase connection.
Net_Ns: Single-phase neutral pin, Network connector on the AC side. Neutral connector. It supports single-phase connection.

Inputs

None

Outputs

Eas: Internal voltage of the source, phase A (V)
Ebs: Internal voltage of the source, phase B (V)
Ecs: Internal voltage of the source, phase C (V)
Ias: Measured current, phase A (A)
Ibs: Measured current, phase B (A)
Ics: Measured current, phase C (A)
Ps: Active power (W)
Qs: Reactive power (VAr).

HYPERSIM Documentation

AC Voltage Source with Impedance