Transmission & Distribution Line Lightning Performance

Sigma SLP: Software for Lightning Performance

Sigma SLP is a simulation software for the computation of transmission and distribution line lightning performance (number of outages to expect), with special reference to the application of line surge arresters (LSA) without and with external gaps. A Monte Carlo statistical method, along with a three-dimensional electro-geometric model is used. The software does complete modeling for electromagnetic transients simulations. The user specifies only readily available data like: line geometry, arrester catalogue data, number of towers in the simulation section of line, insulation critical flashover voltage, etc.

Some of the Sigma SLP characteristics are:

  • Automatic software-driven installation of LSA – no need for user input, in order to optimize line lightning performance improvement.
  • Shielded and unshielded single or multi circuit lines can be simulated. Each three-phase system can have different voltage level.
  • For multi circuit lines, multi circuit outages are directly obtained. Unbalanced (differential) insulation can be simulated.
  • Phase-to-tower and phase-to-phase flashovers using a leader propagation flashover model can be simulated.
  • Surge arrester data is taken directly from the arrester database.
  • Statistical representation of surge arresters currents and energies.
  • Soil ionization tower footing resistance model is automatically implemented. Counterpoise or constant resistance tower footing model can be used.
  • Transients on the tower top, guy wires with a separate grounding, under built ground wires and neutral conductors can be represented.
  • Display of travelling waves along phase conductors and ground wires.
110kA lightning hit to tower top with flashover on middle phase and current discharged through bottom phase LSA