Constant Parameter Lines

SEE ALSO:

Transmission Lines with Fault

Coupled Lines

Triples and Quadruple Lines

Composed Models: Coupled Lines With Fault and Quadruple Lines With Fault

Constant Parameter Lines Icons and Diagrams

The following icons and diagrams are used to represent lines with or without fault.

Properties

Frequency constant distributed parameters lines.

Main Features

A transposed or untransposed frequency constant distributed parameter line is represented by: its sequences, or, by its propagation modes and the transformation matrix (T1) between mode currents and phase currents.

A model of a line with fault is also provided.

Parameter Description

General Parameters

Base MVA	Base power in MVA
Base Volt	Line base voltage - phase to ground in kV
Base Freq	Base frequency (Hz)
Length	Line length (km)
Data base key name	Key to access the line data base (optional package)

Other Parameters

Transposition (Untransposed/Transposed)	“Untransposed” or “Transposed”
Ti	transformation matrix between mode current and phase current ([Iphase] = [Ti] x [Imode]); not used in the case of transposed line
R	Per unit length resistance (ohm/km) for each sequence
L	Per unit length inductance (henry/km) for each sequence
C	Per unit length capacitor (farad/km) for each sequence

Fault Parameters

Distance of fault (side 1): Distance of fault from side 1 (see Figure 7 - 5);
Rdef= (Ra, Rb, Rc, Rg): Fault resistance for phase breakers and ground breaker.

Fault Breaker Parameters
The fault breakers are shown in Figure 7 - 5; Table 7–2shows the types of faults according to the state of the breakers.

Open state resistances	Phase A, B, C and ground: Resistances of phase and ground breakers in open state.
Closed state resistances	Phase A, B, and ground: Resistances of phase and ground breakers in closed state.
Steady state (Grey = Open, Coloured = Closed)	Phase A, B, C and ground: State of phase and ground breakers in steady state.
Programming of operations (from steady state) (Enable/Disable)	Phase A, B, C and ground: “Enable” activates this change.
T1 Operation time	Phase A, B, C and ground: Time when the state of the breakers is changed from the steady state.
T2 Operation time	Phase A, B, C and ground: Time when the state of the breakers changed from the T1, T3 and T4 operation state.
P or C	Specifies if the switching of the breaker three phases is controlled by a command (C) or related to the individual switching timings of each phase (P). The phase (P) operation is mandatory if a Uniform/Gaussian distribution ug/t1/t2/t3 is used. In all other cases the command (C) option is used.

Note: For a phase to ground fault, we strongly recommend using the ground in steady state instead of programming a time of operation in transient state.

Types of fault according to state of breakers

State of Breaker	A	B	C	Ground
No fault	0	0	0	0
Fault between phase C and Ground	0	0	1	1
Fault between phase B and Ground	0	1	0	1
Fault between phases B and C	0	1	1	0
Fault between phases B, C and Ground	0	1	1	1
Fault between phases A and Ground	1	0	0	1
Fault between phases A and C	1	0	1	0
Fault between phases A, C and Ground	1	0	1	1
Fault between phases A and B	1	1	0	0
Fault between phases A, B and Ground	1	1	0	1
Fault between phases A, B and C	1	1	1	0
Fault between phases A, B, C and Ground	1	1	1	1

List of Available Signals

At acquisition, the following signals are made available by the sensors:

Line Signals

V(a, b, c)_line label_bus label	Voltage of each phase on “bus label” bus (volt)
I(a, b, c,n)_line label_bus label	Currents of each phase and ground on “bus label” bus (ampere)
P_line label_bus label	Active power on “bus label” bus (watt)
Q_line label_bus label	Reactive power on “bus label” bus (var)

Fault Signals

Va_FLT_line label	Voltage of phase A on fault bus (volt)
Vb_FLT_line label	Voltage of phase B on fault bus (volt)
Vc_FLT_line label	Voltage of phase C on fault bus (volt)
Ia_FLT_line label	Phase A fault current (ampere)
Ib_FLT_line label	Phase B fault current (ampere)
Ic_FLT_line label	Phase C fault current (ampere)
In_FLT_line label	Ground fault current (ampere)
CMD(a, b, c, n)_FLT_line label	Command for states of phase and ground breakers

Transmission Lines Control Panels

This section shows how to enter data in the control panels of Frequency Constant Parameters

Line Data

Figures 7 - 6, 7 - 7 and 7 - 8, respectively, show the geometric data of a 735kV Hydro-Quebec line.

Load File

An EMTP file that contains the physical parameters of the lines (Fig 7 - 2 and 7 - 3) or the resolve matrix by the external software of EMTP can be loaded automatically in the parameter form.

Calculation of Electrical Parameters

The calculation of electrical parameters of frequency constant parameter lines with their geometric parameters is done by using the Line Generator module in the mask of the line. Figure 7 - 9 shows the relevant part of the geometrical parameters.

Load a file into the Line Generator tab or enter your geometrical line parameters.
Select the transpositions options.
Run the program.
The electrical parameters are displayed in the Line Data report.

Transfer Electrical Parameters to HYPERSIM® Lines

The transfer of electrical parameters to HYPERSIM® is very simple.

In HYPERSIM® GUI, edition mode, draw a network with lines.
Go to the Line Generator tab, in the mask of your line.
To transfer electrical parameters, enter the parameters line.
Load parameters and Apply.
See the parameters in the report log.

Example:
Example of a 735-kV three-phase line. Three bundles of 4.
Bersfort ACSR 1355 MCM conductors.
Two 1/2 inch-diameter steel ground wires.
Figures 7 - 6, 7 - 7 and 7 - 8 show respectively the geometrical data.

Layout of Conductors for a 735kV Line

Details of a Bundle Conductor

Line Height