Numerical Model for High Voltage Insulating String Behavior

Knowing how insulating strings behave to different types of electrical stresses is useful in several situations including: designing the overhead transmission line and choosing the protection devices or the right interpretation of the records generated by the SCADA system. The integrity of the insulating strings is tested at commissioning and it can periodically be verified using laboratory tests involving standardized voltage forms. As a result, their behavior is well documented at lightning and switching impulse voltage, without insisting on other random voltage forms. Considering that during normal operation the electric stresses do not have standardized forms, we propose a numerical model in ATPEMTP that approximates the behavior of the insulator strings to any impulse voltage variation for different geometries and different weather conditions using the results obtained during standardized laboratory tests.