Description
The PI line model is mainly used for short transmission lines. The equivalent circuit is shown below. It is assumed that the capacitance on both sides are identical. The RL branches are also coupled.
This model can be used to simulate an internal fault. However, the number of operations allowed in this model is four (4) per fault element, instead of ten (10) in normal cases.
Mask and Parameters
General Parameters
| Name | Description | Unit | Variable = {Possible Values} | |||
|---|---|---|---|---|---|---|
| Description | Use this field to add information about the component | Description = {'string'} | ||||
| EMTP (.pun) file for line parameters calculation | The location (path) of the EMTP file (pun file) containing the line parameters. However, The EMTP “.pun” format is not allowed with this model | File = {'path.name'} | ||||
| Line 1 | Fault distance from (+) side | km | fault_loc = {0, 1e64} | |||
| Type | The line data can be taken using Matrix or Sequence parameters | Matrix/Sequence = { 0, 1} | ||||
| Matrix {0} | Untransposed line. The data is filled in the matrices | |||||
| Sequence {1} | Transposed line. The data is filled in the sequences | |||||
| Line Length | The length of the line | km | length = {0, 1e64} | |||
| Base power (perPhase) | Base value for PU conversion | MVA per phase | pBase = { [1, 1e64] } | |||
| Base voltage (rmsLN) | Base value for PU conversion | kV rms LN | vBase = { [1, 1e64] } | |||
| Base frequency | Base value for PU conversion | Hz | fBase = { [1, 1e64] } | |||
| Fault resistance | Fault resistance value per phase | Ω | RDef = {0, 1e64} | |||
| Ropen | Open resistance value per phase | Ω | ROpen = {0, 1e64} | |||
| Rclose | Closed resistance value per phase | Ω | RClose = {0, 1e64} | |||
| Chopping current | Current threshold for the opening permission operation | A | Imargin = {0, 1e64} | |||
Matrix Parameters
| Name | Description | Unit | Variable = {Possible Values} | |||
|---|---|---|---|---|---|---|
| Resistance - R | Resistance matrix | Ω/km | R = {'-1e64, 1e64'} | |||
| Inductance - L | Inductance matrix | H/km | L = {'-1e64, 1e64'} | |||
| Capacitance - C | Capacitance matrix | F/km | C = {'-1e64, 1e64'} | |||
Sequence Parameters
| Name | Description | Unit | Variable = {Possible Values} | |||
|---|---|---|---|---|---|---|
| R | Resistance value for Zero and Positive sequences | Ω/km | Rseq = {'-1e64, 1e64'} | |||
| L | Inductance value for Zero and Positive sequences | H/km | Lseq = {'-1e64, 1e64'} | |||
| C | Capacitance value for Zero and Positive sequences | F/km | Cseq = {'-1e64, 1e64'} | |||
Timing Parameters
| Name | Description | Unit | Variable = {Possible Values} | |
|---|---|---|---|---|
| Time units | Units applied to the programmed state transition operations | Ut = {s, ms, c} | ||
| Second {s} | All operations Tn are in seconds | |||
| Millisecond {ms} | All operations Tn are in milliseconds | |||
| Cycle {c} | All operations Tn are in electrical cycles (setting the frequency is mandatory) | |||
| Time programming | Master switch that determines whether the programmed operations will occur upon triggering an acquisition | EnaGen = {0, 1} | ||
| Disable {0} | Programmed operations are disabled | |||
| Enable {1} | Programmed operations are enabled | |||
| Steady-state condition | State of phase breakers in steady-state; “colored” if the breaker is open and “grey” if the breaker is closed | iniStateA = {0, 1} iniStateB = {0, 1} iniStateC = {0, 1} iniStateG = {0, 1} | ||
| Frequency | Should be set using the parameter "Base frequency". | Hz | Freq = { [45, 70] } | |
Switching times Line1 | Enable/disable the state transition operation on the same line. | EnaT1 = {0, 1} EnaT2 = {0, 1} ... | ||
| Disable {0} | Disable the state transition operation on the same line | |||
| Enable {1} | Enable the state transition operation on the same line. If the line is enabled but no information is filled, the state transition operation is ignored. | |||
Switching times Type(f,i,u,ug) | Relative time (with respect to POW synchronization) when the command is sent to the breaker (or switch) to change state. There are four ways to input this time. Important notes:
| Refer to "Time units" parameter | T1 = {'string'} T2 = {'string'} ... | |
| Fixed | {f: fixed time} At each acquisition, Tn command is sent at the same time for all phases selected in "Phase operated". | |||
| Incremental | {i: initial time/final time/time increment} For the first acquisition, Tn command is sent at the set initial time for all phases selected in "Phase operated". Then at each acquisition, Tn command is sent a time increment later than the previous acquisition. Once the final time is reached, the next acquisition will be done using the initial time again. | |||
| Uniform | {u: minimal time/maximal time} At each acquisition, Tn command is sent at a random time. The probability is uniform over the specified range. All phases selected in "Phase operated" DO NOT receive the command at the same time, it is also random. | |||
| Uniform gaussian | {ug: minimal time/maximal time/ dispersion} At each acquisition, Tn command is sent at a random time. The probability follows a gaussian distribution over the specified range. All phases selected in "Phase operated" DO NOT receive the command at the same time, it is also random. | |||
| Referenced operations | Use to refer the triggering of Tn to another breaker programmed state transition. See the Referenced Operations section for more information. NB: all columns must be filled for the referenced operation to work. | |||
| Ref operation | Name (or path) of the breaker to which the timing is referenced | Eref1 = {'path.name'} Eref2 = {'path.name'} ... | ||
| Ref time | Time Tn ID of the referenced breaker's step to which the timing is referenced | Tref1 = {Tn} Tref2 = {Tn} ... | ||
| Phase/Command | Activate (Phase {1}) or deactivate (Command {0}) the reference dependency | T1RPh = {0, 1} T2RPh = {0, 1} ... | ||
| Phase operated | The list of all phases that will change state when the timing condition is reached. So if after Tn-1 the A and C phases are OFF and Tn triggers B and C, after Tn phases A and B will be OFF, and C will be ON. | T1Pa, T1Pb, T1Pc = {0, 1} T2Pa, T2,Pb, T2Pc = {0, 1} ... | ||
| ON {1} | "Colored" when a state transition shall occur | |||
| OFF {0} | "Grayed out" when no state transition shall occur | |||
Ports, Inputs, Outputs and Signals Available for Monitoring
Ports
This component supports a 3-phase transmission line
Name | Description |
|---|---|
| net_1(a,b,c) | Network connection of phases (a,b,c) of the left (+) side |
| net_2(a,b,c) | Network connection of phases (a,b,c) of the right side |
Inputs
None
Outputs
None
Sensors
At acquisition, the signals available by the sensors are:
Name | Description | Unit |
|---|---|---|
| V(a,b,c)_FLT | Voltage on fault bus phases (a,b,c) | V |
| I(a,b,c,n)_FLT | Fault current (a,b,c,n) | A |
| CMD(a,b,c,n)_FLT | Command for states of phase and ground breakers |
Calculation of Electrical Parameters
The EMTP “.pun” format is not allowed with this model. However, the electrical parameters of PI lines can be calculated by using the HyperView Line Tab module in HyperView.
Steps are as follows:
- Load a file into the Line Data GUI or enter the geometrical line parameters; details are found in Line Geometry
- Select the transposition options
- Run the program
- The electrical parameters are displayed in the Line Data Report
To transfer the electrical parameters to the PI model, follow these steps:
- Go to the Line Data GUI
- The names of the lines in your network are at the bottom of the page
- To transfer electrical parameters, choose the name of the line and click Apply
- See the parameters in the forms of the line
Types of fault
The fault breakers are shown in the following figure. The types of faults according to the state of the breakers are listed in the table.
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 |
In the case of a 3-phase line with fault, two configurations are available to the user:
- 1 line section - no fault
- 2 line sections - fault on the line
The user must specify the fault distance on the line. This distance must be calculated from side “1” of the line. For example, if the user wants to simulate a fault on the line at a distance of 125 km he must enter the value in the fault distance fields. If the user does not want to use the fault element, he must set the value of the fault distance to 0. It should be noticed that the fault distance must be lower than the line length.