Mask and Parameters
|Simulation mode||Defines the mathematical models of the distributed parameters line used by ARTEMiS and SPS. Here are the available options:|
• SimPowerSystems: When this option is selected the block uses the SPS mathematical model that is not optimized for real-time simulation.
• ARTEMiS model: When this option is selected the block uses the ARTEMiS mathematical model that allows fast real-time simulation and that allows network decoupling.
|Number of phases N||Specifies the number of phases, N, of the model. The block dynamically changes according to the number of phases that you specify. When you apply the parameters or close the dialogue box, the number of inputs and outputs is updated.|
|Frequency used for RLC specifications||Specifies the frequency used to compute the resistance R, inductance L, and capacitance C matrices of the line model.|
|Resistance per unit length||The resistance R per unit length, as an N-by-N matrix in ohms/km. For a symmetrical line, you can either specify the N-by-N matrix or the sequence parameters. For a two-phase or three-phase continuously transposed line, you can enter the positive and zero-sequence resistances [R1 R0]. For a symmetrical six-phase line you can set the sequence parameters plus the zero-sequence mutual resistance [R1 R0 R0m]. For asymmetrical lines, you must specify the complete N-by-N resistance matrix.|
|Inductance per unit length||The inductance L per unit length, as an N-by-N matrix in henries/km (H/km). For a symmetrical line, you can either specify the N-by-N matrix or the sequence parameters. For a two-phase or three-phase continuously transposed line, you can enter the positive and zero-sequence inductances [L1 L0]. For a symmetrical six-phase line, you can enter the sequence parameters plus the zero-sequence mutual inductance [L1 L0 L0m]. For asymmetrical lines, you must specify the complete N-by-N inductance matrix.|
|Capacitance per unit length||The capacitance C per unit length, as an N-by-N matrix in farads/km (F/km). For a symmetrical line, you can either specify the N-by-N matrix or the sequence parameters. For a two-phase or three-phase continuously transposed line, you can enter the positive and zero-sequence capacitances [C1 C0]. For a symmetrical six-phase line you can enter the sequence parameters plus the zero-sequence mutual capacitance [C1 C0 C0m]. For asymmetrical lines, you must specify the complete N-by-N capacitance matrix.|
|Line length||The line length, in km.|
|Measurements||Line current and voltage measurement are not working.|
Inputs and Outputs
N-Phase voltage-current signals
N-Phase delayed voltage-current signals.
Characteristics and Limitations
The ARTEMiS distributed parameters line block does not initialize in steady-state so unexpected transients at the beginning of the simulation may occur.
The use of the ARTEMiS Distributed Parameter Line disables the Measurements option of the regular Distributed Parameter Line. Usage of regular voltage measurement blocks is a good alternative.
|Discrete sample time||Yes, defined in the ARTEMiS guide block.|
The example shows how to use the ARTEMiS distributed parameters line to decouple an electrical network into two distinct subnetworks and consequently to optimize the time to simulate the system in real-time. This property also allows ARTEMiS to simulate systems that contain more switching elements and consequently more complex systems.
Note: The procedure shown below can also be applied to ARTEMiS Stubline block to decouple subnetworks and optimize real-time simulation.
- Open the SPS demo power_monophaseline model by typing the following command in the command prompt of Matlab: power_monophaseline;
- To become familiar with the example, consult the help and perform simulation and check the results. The next steps will modify the demo to use the ARTEMiS solver instead of the normal SPS solver.
- Drag an ARTEMiS Guide block from the ARTEMiS library into the model and set it sample time to 50e-6 seconds.
- Set the SPS PowerGUI block to <Discrete> mode with a sample time equal to ARTEMiS
- Change the Distributed Parameter Line line block of SPS to the ARTEMiS block and copy the original line parameters in the ARTEMiS Line model. Optionally, one can use the opReplaceSpsBlocks function. At the MATLAB prompt type: opReplaceSpsBlocks('power_monophaseline', 'ReplaceSpsBlocks');
- The model must be similar to the following figure. Save the model under the following name: power_monophaseline_artemis.mdl.
Simulate the model and analyze the results. You will see that the results are similar to the original model.
- The next steps will show you how to run the model on a cluster of PCs running RT-LAB. The general idea is to benefit from the intrinsic delay of the transmission line to split the model into subnetworks. The mathematical model of the distributed parameters line of ARTEMiS, contrary to the SPS model, allows distribution of the line onto two different CPUs. This property also allows ARTEMiS to simulate systems containing more switching elements and consequently more complex systems.
- Select all blocks located in the subnetwork 1 in the figure above and press Ctrl-G to create a new subsystem.
- Move the ARTEMiS block inside the subsystem.
- Rename this subsystem to SM_Subnetwork_1. The following figure displays the content of the SS_Subnetwork_1 subsystem.
- Select all blocks located in the subnetwork 2 and press Ctrl-G to create a new subsystem.
- Add an ARTEMiS Guide block inside the subsystem.
- Rename this subsystem to SS_Subnetwork_2. The following figure illustrates the content of the SS_Subnetwork_2 subsystem.
- Select the 3 remaining blocks, normally the two scopes blocks and the Mux1 block and press Ctrl-G to create a new subsystem.
- Rename this subsystem to SC_Console.
- Add the RT-LAB opcomm block between the inports blocks and the content of the subsystem. Don’t forget to set the number of inports of the OpComm blocks to 3. Refer to the RT-LAB user guide for more help.
- The following figure illustrates the content of the SC_Console subsystem after the modifications described above have been made.
- Modify the solver parameters of the model; select one of the fixed-step solver, like ode3 for example, and change the fixed-step size to 50e-6.
- Organize the top level blocks according to the following figure. IMPORTANT: the powerGUI block must be at the top level.
- Save your model.
- Your model is now ready to be compiled with RT-LAB. Refer to the RT-LAB User Guide for more help. If you have set the sample times of your model with a variable set in the workspace (ex: Ts), you should set the model initialization function with <Ts=50e-6;> in File->Model Properties->Callbacks→InitFcn
Usage 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 distributed parameters line must be located on the top-level of the RT-LAB compatible Simulink model
- Each ARTEMiS distributed parameters line outports can be connected only to SimPowerSystems component located inside the RT-LAB top-level subsystem (names beginning with ’SS’ or ’SM’ prefixes)
- No connection between ARTEMiS distributed parameters lines is allowed on the top-level. If such a connection is required, the ARTEMiS distributed parameters block connection lines must be first routed inside the subsystems individually and the connection between the ARTEMiS distributed parameters line ports can be made inside the subsystem. The following figure shows an example of illegal ARTEMiS DPL connection at the RT-LAB top-level and how to connect the line inside an RT-LAB top-level subsystem.