Analysis and Calculation of Substation’s Internal Electric Field Intensity Caused by Incoming and Outgoing Lines

In ultra-high voltage transmission system, the electrostatic induction generated by power frequency electric field will exerts negative effects on the electrical automation equipment within the substation and, in particular, will leads long-term harm to staffs’ health. However, researches of electric field environment in ultra-high voltage transmission system merely concentrate on calculating the electric field intensity caused by three-phase limited length wire or three-phase infinite wire within the transmission, without considering the method of calculating half-infinite wire which represents “one end is fixed, while the other end is infinite length’s wire”. Consequently, a new method named “Charge Simulation-Genetic Algorithm (CS-GA) method” which can efficiently calculate power frequency electric field inside of the substation is proposed in the paper. In CS-GA method, the effective calculating length is determined by genetic algorithm method’s optimization, which in other words, half-infinite length wire is substituted for limited length wire in calculating the electric field intensity. The simulation results indicate that CS-GA method is a relatively accurate, efficient and reasonable way on calculating the power frequency electric field inside of the substation.