Page Content

1 Description
2 Mask and Parameters
3 Inputs and Outputs
- 3.1 Inputs
- 3.2 Outputs
4 Example
- 4.1 Offline Usage Example
5 Characteristics and Limitations
- 5.1 Usage of the FD-line model in RT-LAB as task decoupling elements
- 5.2 Initialization

Description

The ARTEMiS-SSN Frequency Dependent Line block implements an N-phase distributed parameters transmission line model with frequency dependence of line parameters.

The ARTEMiS-SSN Frequency Dependent Line block implements an N-phase distributed parameters line model with frequency dependence of line parameters. The model is based on the Marti’s model used by the Electromagnetic Transient Program (EMTP-RV) [1][2]. This model is optimized for discrete real-time simulation and allows network decoupling. It also allows multi-CPU simulation on an RT-LAB simulator.

Mask and Parameters

Number of phases	the number of phase of the model (1-2-3-6)
Line data variable	the name of a MATLAB workspace variable containing the FD_line parameter. The variable is a structure containing the various parameter of the model.
>>fdfit =
Nph	[1x1 struct] number of phase
NpolY	[1x1 struct] number of poles for Yc(s) (Yc=1/Zc)
Ypol	[1x1 struct] poles of Yc(s)
Yres	[1x1 struct] residues of Yc(s)
YDmat	[1x1 struct] constant residues of Yc(s)
NpolH	[1x1 struct] number of poles of H(s)
Hpol	[1x1 struct] poles of H(s) (propagation function)
Hres	[1x1 struct] residue of H(s)
HDmat	[1x1 struct] minimum propagation delays
Ti	[1x1 struct] current transformation matrix
Tv	[1x1 struct] voltage transformation matrix
And each component being itself a structure with Data and Name parts. For example: >> fdfit.NpolY
Data	[3x1 double]
Name	Number of poles for each mode in Ycm
The document untitled 'Obtaining FD-line model parameters from EMTP-RV' explains how to get these parameters from the fitting routines of EMTP-RV. It can be found in the installation repository of ARTEMiS: pathtorepository/ARTEMiS/artemis_version/art_r201XY/auxiliary_routines/marti_fd_line/line_param/Obtaining_FDline_model_parameters_from_EMTP_RV.pdf
Unique Tag Identifier	a user set string that must be unique for each instance of this block inside a Simulink model. (Note: in future releases, this parameters will be set automatically and will not be visible from the user)
Voltage measurement and Current Measurement choice	User decides if they want to measure others parameters of the line like phase voltage or phase current. (Note: the voltage is a phase-to-ground measurement)
Voltage and Current Label	User can specify a label for its current or voltage values. In case the previous choices have been set up to yes, current and voltage labels provided by the user are used to retrieve current. This can be performed using ‘label_’s for the sending side of the line ( the one connected to the source) and ‘label_r’ for the receiving side of the line.

Inputs and Outputs

Inputs

N-Phase voltage-current signals

Outputs

N-Phase delayed voltage-current signals.

Example

Offline Usage Example

The FD-line model interfaces with and only with the SSN method. The reason for this is that the FD-line model is internally coded with the nodal approach.

To make this interface, the FD-line model must be used in conjunction with SSN Nodal Interface Blocks (NIB) with the X-type interface chosen in the direction of the FD-line. The NIB can connect to other SSN groups of either V- I- or X-type.

The curve below shows the source energization current while phase C is connected to the 1Ω-1mH single phase load.

The top-level separated model for RT-LAB will have the ARTEMiS-SSN Frequency Dependent Line model stay at the top-level of the diagram as shown below.

And with the NIB block inside the SM_Master and SS_Slave subsystems as depicted below:

Compilation of this model in RT-LAB will result in two independent tasks (SM_Master and SS_Slave) interconnected by the 2 FD-line which will transmit their propagation voltages and currents between the two subsystems.

Characteristics and Limitations

Usage of the FD-line model in RT-LAB as task decoupling elements

When used in RT-LAB to decouple and separate computational tasks on different cores/CPUs, the following connection restriction are applicable to the ARTEMiS distributed parameters line model:

The ARTEMiS-SSN Frequency Dependent Line must be located on the top-level of the RT-LAB compatible Simulink model
Each ARTEMiS-SSN Frequency Dependent Line outports can be connected only to Simscape Electrical Specialized Power Systems (SPS) components located inside RT-LAB top-level subsystem (names beginning with ’SS’ or ’SM’ prefixes)
No connection between ARTEMiS-SSN Frequency Dependent Lines is allowed on the top-level. If such a connection is required, the ARTEMiS-SSN Frequency Dependent Line block connection lines must be first routed inside the subsystems individually and the connection between the ARTEMiS-SSN Frequency Dependent Line ports can be made inside the subsystem.

SSN solver in the ARTEMiS GUIde block

The SSN solver of the ARTEMiS GUIde block must be ’Trapezoidal’ when using a ARTEMiS-SSN Frequency Dependent Line block. This is because the Trapezoidal solver is used internally by the ARTEMiS-SSN Frequency Dependent Line block.

Initialization

The ARTEMiS-SSN Frequency Dependent Line block does not initialize in steady-state so unexpected transients at the beginning of the simulation may occur.

Direct Feedthrough	No
Discrete sample time	Yes, defined in the ARTEMiS guide block
XHP support	Yes
Work offline	Yes