Simulation Of Lightning Transient Of Overhead Line Towers

As the development of industry and the rise of electrical load, the super high voltage transmission lines have been greatly developed. The probability of lightning stroke on a tower increase when the tower heightens. When a stroke hits a transmission tower, the injected current propagates toward the ground through the tower's body causing an transient rise of the tower voltage. This may result in a back-flashover and lightning surge on the transmission lines. This over voltage invades to substations and led to lightning stroke trip. In order to prevent the power failure caused by lightning, correctly estimate the performance of lightning wave on transmission lines is very important, and this needs the more accurate model of the transmission line tower.On the basis of the former research about models of transmission line tower, founding the equivalent distributed constant line model of transmission line tower by doing some improvement on the inductance equivalence model and the single wave impedance model of transmission line tower. This paper considers the insulator flashover character and tower ground surging character. This paper gives the algorithm about polyphase transmission line transient phenomenon. By programming, founding the insulator u-t characteristic model. The agreement between the result of the paper and experimental result has been found satisfactory. This shows that the transmission line tower model founded in the paper may be used in the engineering calculation and reflects tower lightning characteristic.