Research on electromagnetic character of 500/220kV mixed-voltage quadruple-circuit transmission line

Electromagnetic environment is one of the key problems restricting the construction of quadruple-circuit transmission line on the same tower. In the paper, we use charge simulation method and current simulation method to calculate the electromagnetic character of 500/220kV mixed-voltage quadruple-circuit transmission line and analyze the influences to the surrounding environment. In the experiments, the electromagnetic field distribution near the ground(1.5m from the ground) of 500/220kV mixed-voltage quadruple-circuit transmission line of 3 typical tower types and 12 phase sequence arrangements are calculated, and from the results we can find out the advantages and disadvantages of the three tower types and optimal or worst phase sequence arrangements. Furthermore the impact of minimum conductor height to the ground on electromagnetic field distribution is also analyzed. Through the experiments it is able to be verified that the 500/220kv mixed-voltage quadruple-circuit transmission line is quite feasible, which provides powerful references for the construction of other mixed-voltage multi-circuit transmission line.