Insulation Coordination Study of 400 kV High Voltage Substation

Insulation coordination is defined as the selection of the dielectric strength of the equipment compared to the voltages that appear on the system to which the equipment is intended, taking into account the service environment and the characteristics of the available protection devices. Several approaches have been proposed to study the lightning overvoltages that propagate along the line connected to the substation. As far as the random nature of the lightning phenomenon is concerned, the procedure must be statistical and the Monte Carlo method is generally used for this type of study. The goal is to evaluate the lightning performance of a complete air-insulated substation (AIS) using the capability of simulation tools. This technique was coded in MATLAB and linked to the EMTP program to perform network simulations. Due to the very long time required to perform the simulation, an acceleration process using parallel computing has been applied. The present study has not only been used to estimate the mean time between failures (MTBF) of the substation but also to select the necessary surge arresters and the appropriate basic insulation level (BIL). This study is carried out using an operational 400 kV high voltage substation.