Line and Cable Model

Introduction

This device is used for modeling transmission lines or cables. It is the most sophisticated line and cable modeling technique available. It represents the complete frequency dependence of parameters and constitutes a wideband model. More theoretical details and qualifications can be found in [1].

Available versions

There is only a multiphase version of this device. It is not allowed to change phases. It is assumed that such options are selected before making final connections to the line.

Parameters

The user must enter the Number of conductors and select the model data file. The model data file is obtained from the “WB fitter” device.

Generic Rules

The model data file format must be the one given in the “WB fitter” device. There is no extra testing for wrong data or numerically unstable cases.

It is not allowed to delete any pins or change pin attributes. The drawing of this device is continuously updated according to the selected number of conductors.

Initial Conditions

Automatic initial conditions are found from the harmonic steady-state solution. The line is initialized for quickly achieving steady-state conditions in time-domain at simulation startup.

Time-Domain Model

The time-domain representation is explained in [1]. Rules similar to the CP-line model are enforced.

Fitter

Wideband Fitter Introduction

This device is used for generating data for the Wideband line/cable model “WB m-phase” device. The fitting technique is described in [1].

Parameters

This device accepts Model data file from the “Line Data” or “Cable Data” functions. After running and generating model data, the user can reopen the “WB fitter” and visualize the fitting results for the characteristic admittance Yc and the propagation function H.
The data generated by this device is referenced in the Wideband line/cable model. The convergence tolerance is a relative tolerance; it can be modified when fitting problems are encountered. The default value is acceptable in most cases.

References

[1] Morched A., Gustavsen B., Tartibi M.: “A universal model for accurate calculation of electromagnetic transients on overhead lines and underground cables”. Power Delivery,
IEEE Transactions, Volume: 14, Issue: 3 , July 1999, pp. 1032 -1038 EMTP