Decoupling Line (Three-Phase)
Three-phase decoupling distributed parameters line
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Simscape / Electrical / Specialized Power Systems / Fundamental Blocks
Description
The Decoupling Line (Three-Phase) block implements a three-phase distributed parameters line model that transmits the electrical signal entering its conserving ports to an associated Decoupling Line (Three-Phase) block in your model. The two Decoupling Line (Three-Phase) blocks form a pair that represents the send and receive ends of a three-phase transmission line.
The behavior of the pair of blocks is equivalent to using one Distributed Parameters Line block:
Refer to Distributed Parameters Line for a detailed description of the equations used to represent wave propagation phenomena and line-end reflections.
Use the Decoupling Line (Three-Phase) block pairs when you want to model a transmission line with no physical electrical connections between the send and receive ends of the line. This technique is used, for example, in applications where a large network is decoupled into smaller sections that are simulated into different subsystems or models with no electrical connections between them. This decoupling technique is often used to model complex electrical networks on multi-core real-time computers, or to allow faster simulation of large networks.
The blocks in the a pair can be associated by using the Pairing ID parameter, which transmits the electrical signal information travelling from one terminal to the other by using internal Simulink® Goto and From blocks or connecting the blocks with Simulink signals.
The parameters of each Decoupling Line (Three-Phase) block in the a pair must be identical and correspond to the parameters you would enter in an equivalent Distributed Parameters Line block. For example, to model a 100 km transmission line with the given R, L, and C values, use two Decoupling Line (Three-Phase) blocks with a length of 100 km each and the same R, L, and C values.
To model a transmission line in your model, add two Decoupling Line (Three-Phase) blocks to your model and set the block parameters to the same values. Alternatively, use the Specify Decoupling Lines App to find, select, and automatically replace existing Distributed Parameters Line blocks in your model with equivalent pairs of Decoupling Line (Three-Phase) blocks. For more information, see Specify Decoupling Lines.
Limitations
The Decoupling Line (Three-Phase) block can be used only in a discrete model, that is, when the Simulation type parameter of the powergui block is set to
Discrete.
Ports
Input
Output
Conserving
Parameters
Parameters
Line length (km) — Transmission line length
100 (default) | positive scalar
Transmission line length, in km. Because the block is used with another Decoupling Line (Three-Phase) block, enter the same line length in each of the two blocks; do not split the value between each of the two blocks. For example, to model a 100 km line, specify 100 in each block, not 50 in one block and 50 in the other block.
Frequency used for rlc specification (Hz) — Line frequency
60 (default) | positive scalar
Specify the frequency used to compute the per-unit length of the resistance R, inductance I, and capacitance C matrices of the line model.
Resistance per unit length (ohms/km) [ 3x3 matrix ] or [ r1 r0 ] — Line resistance
[0.01273 0.3864] (default) | two-element vector | three-element vector | 3-by-3 matrix
Resistance R per unit length, specified as a two-element vector or a 3-by-3 matrix, in ohms/km (Ω/km).
For a symmetrical line, specify either the 3-by-3 matrix or the sequence parameters.
For a three-phase continuously transposed line, enter the positive and zero-sequence resistances [r1 r0].
For asymmetrical lines, specify the complete 3-by-3 resistance matrix.
Inductance per unit length (H/km) [ 3x3 matrix ] or [ l1 l0 ] — Line inductance
[0.9337e-3 4.1264e-3] (default) | two-element vector | three-element vector | 3-by-3 matrix
Inductance I per unit length, specified as a two-element vector or a 3-by-3 matrix, in henries/km (H/km).
For a symmetrical line, specify either the 3-by-3 matrix or the sequence parameters.
For a three-phase continuously transposed line, enter the positive and zero-sequence inductances [l1 l0].
For asymmetrical lines, specify the complete 3-by-3 inductance matrix.
Capacitance per unit length (F/km) [ 3x3 matrix ] or [ c1 c0 ] — Line capacitance
[12.74e-9 7.751e-9] (default) | two-element vector | three-element vector | 3-by-3 matrix
Capacitance C per unit length, specified as a two-element vector or a 3-by-3 matrix, in farads/km (F/km).
For a symmetrical line, specify either the 3-by-3 matrix or the sequence parameters.
For a three-phase continuously transposed line, enter the positive and zero-sequence capacitances [c1 c0].
For asymmetrical lines, specify the complete 3-by-3 capacitance matrix.
Show send and receive ports — Ports enabling
off (default) | on
Select to show the r and s input and output ports. When selected, the Decoupling Line (Three-Phase) blocks can be paired by connecting them with Simulink signals. You connect the s output of the first block to the r input of the second block, and connect the s port of the second block to the r port of the first block
The internal model of the Decoupling Line (Three-Phase) block is directly connected to the external r and s block ports.
To break the algebraic loop created by this type of connection, you can add Unit Delay block at the output of each Decoupling Line (Three-Phase) block.
When Show send and receive ports is cleared, the Decoupling Line (Three-Phase) blocks are associated by using the Pairing ID parameter, which transmits the electrical signal information travelling from one terminal to the other by the use of internal Simulink Goto and From blocks. A Unit Delay block is also added to the output signal path to break the algebraic loops. The sample time parameter of this delay corresponds to the sample time delay specified in the powergui block.
Pairing ID — Pairing identifier
L001 (default)
When the Show send and receive ports parameter is cleared, internal
Goto and From blocks are used to pair
two Decoupling Line (Three-Phase) blocks in your model.
In both blocks, the first part of the pairing identifier is the same,
but you must append _S to the end of the identifier
of one block, and _R to the end of the identifier of
the other block. An error is produced if the identifier does not end in
_S or _R. For example, suppose
you add two Decoupling Line (Three-Phase) blocks to your
model. To pair the blocks, you must set the Pairing
ID parameter of one block to L001_S
and the other block to L001_R.
Initial Values
Initial voltage (V) — Initial voltage
[ 1 1 1] (default) | three-element vector
Initial value of the terminal voltage, in volts.
Initial voltage angle (Deg) — Initial angle
[0 -120 120] (default) | three-element vector
Angle of the initial voltage, in degrees.
Initial current (A) — Initial current
[ 1 1 1] (default) | three-element vector
Initial value of the current flowing out the block, in Amperes.
Initial current angle (Deg) — Initial angle
[0 -120 120] (default) | three-element vector
Angle of the initial current, in degrees.