Specialized Software for Electrical Design of Overhead Lines by Igor Gutman
Specialized software has become available to assist statistical dimensioning of insulators intended for service in polluted areas. The methodology took 10 years to develop including conversion into software that verifies calculations by comparison with service experience. For example, the Line Performance Estimator (LPE) Program goes back to the 1990s when the Norwegian TSO started a major upgrade of 300 kV AC lines to 400 kV with the requirement that system reliability would remain the same. This was resolved using statistical dimensioning which, after implementation, was converted into software that is presently available for both AC and DC applications. The capability of the LPE program is not limited to pollution performance but also includes insulator icing as well as lightning and switching overvoltage performance. The aim is to provide users with a complete view of the estimated insulation performance of any transmission line as a function of insulator length. The program not only estimates performance of the complete line but also shows how calculated insulation failure rates are distributed among different line sections. This presentation provides a description of these software programs, their features as well as relevant theoretical background and also discusses practical cases where they have been implemented.