How do you model frequency dependent line parameters for cables and overhead lines for harmonic analysis using TypLne?
Harmonic load flow calculation and frequency sweep calculations require detailed models of lines that are also representative for higher frequencies.
For that purpose, overhead lines and cable systems are ideally modeled based on their geometry using TypTow, TypGeo and TypCabsys.
However, the user might be restricted to the use of TypLne line models. In this case, the user can assign a frequency dependent characteristic to the following parameters:
- Positive and zero sequence resistance R1, R0
- Positive and zero sequence inductance L1, L0
The capacitance of overhead lines and cables can be considered to be constant over the frequency range of typical harmonics.
The frequency dependent parameters for R1, R0, L1 and L0 can assign on the PowerQualitiy/Harmonics page of the corresponding line type (TypLne) as shown in the attached example. The charactersistic is assign as follows:
- Create a Frequency Scale (TriFreq) e.g. from 1 Hz to 2.5 kHz
- Create a Parameter Characteristic - Vector (ChaVec)
- Select the TriFreq
- Assign the characteristic e.g. from the attached Excel sheet as relative p.u. values
- Assign the ChaVec to R1, R0, L1 and L0 on the Harmonics page of TypLne
The frequency characteristic is either provided from the manufacturer, based on typical values in the literature or can be derived from geometric models in PowerFactory.