On lightning withstand level of composite insulators;

The influence of the line arrester on the lightning withstand level of 35 kV transmission lines was simulated and calculated by electromagnetic transient software ATP-EMTP.

There are two indexes to evaluate the power line performance on preventing lightning strikes: the one is the lightning trip-out rate,the other is the lightning withstand level of the power line.

For the purpose of improving the ability of lightning protection for the high voltage power transmission line,taking account of the facts which influenced the lightning protection level,an assessment model was established and the comprehensive judgement on the lightning protection level was obtained by means of computers.

The formula for the calculation of the lightning protection level of the transmission line is revised by theoretic deduction for the rational determination lightning protection level and lightning trip-out rate of the transmission line.

To enhance lightning withstanding level of 500 kV transmission line along mountainsides,a novel approach was proposed.

According to the specific structure of towers,the lightning withstanding level of 330kV transmission lines with line metal-oxide arrester(MOA)is analyzed.

The lightning withstanding level of 500 kV Chang-Fang compact designed transmission line can be greatly improved with installed line surge arresters on transmission towers.

For the sake of increasing the lightning impulse withstand level of 110 kV transmission line, MOA is adopted.