Experimental study is an effective and useful method to research lightning shielding performance of transmission lines directly. Research actuality on tests of lightning shielding performance of transmission lines is described roughly in this paper. Theoretical analysis and investigation is conducted on view of 4 aspects

including rationality of scaled model test

grounding method of scaled conductor

operating voltage applied to scaled conductor

and polarity of applied voltage to simulate lightning. Practical tests with scaled model should be geometrically and physically consistent with original system. Therefore

it is to propose in this paper that switching impulse with short wave front is proposed to large-scaled transmission line model. Preliminary study conducted in this paper indicates that there’s a significant influence on the 50% discharge voltage of rod-conductor air gaps with the conductor grounded or not. Optical observation can be employed to research on the mechanism of grounding method’s influence on discharge process

to build a theoretical basis for future study. Operating voltage applied to scaled conductor should be different for DC and AC transmission lines. Different polarities of applied voltage to simulate lightning should be employed in simulation test

and comparison should be conducted to have the one with a smaller shielding scope

which will provide references and basis for lightning shielding performance of UHV transmission lines.