In this study, the problem of optimal parameters in charge simulation method (CSM) is solved using the genetic algorithm (GA), particle swarm optimisation and differential evolution. The comparative study shows that the GA is more effective. A model based on a hybrid approach that combines CSM and the GA is proposed to calculate the electric field created by an overhead extra high voltage power line. The resulting field levels were compared with exposure values set by the ICNIRP and IRPA standards. The results show that these levels are less than the limit recommended by these standards. The simulation results of electric field intensity values are compared with those obtained from polarisation ellipse method. A good agreement has been reached.