Aiming at the shortcomings of the analysis of voltage characteristic mechanism of UHV half-wavelength AC transmission system

we explained the steady-state voltage and fault voltage characteristics in detail.Moreover

we analyzed the steady-state voltage characteristics of half-wavelength lines and their influencing factors based on the distributed parameter model.Distribution characteristics of charging power and reactive power loss along half-wavelength line were deduced and the maximum voltage and its position were solved.Then

based on the fault equivalent circuit

fault voltage characteristics along half-wavelength line influenced by different fault types and system strengths were analyzed

and the mechanism of severe faults due to series resonance was explained.The simulation results based on a real power system show that overload and low power factor lead to overvoltage under a steady state

and series resonance overvoltage occurs under faults in 100

4

00 km ranges away from terminals

verifying the correctness of the foregoing analysis.