Application investigation on parallel gap of composite insulators for 110 kV transmission line in high intensity lightning area

The parallel gap lightning protection device is beneficial to the existing lightning protection measures for overhead transmission line and has broad application prospects. The application investigation on parallel gap lightning protection device of composite insulators for the 110 kV overhead transmission line used in high intensity lightning area is present in this article. A variety of parallel gap lightning protection device are designed. The functions of its guiding lightning discharge, transferring power-frequency arc, uniforming power-frequency electric field and protection of insulators and fittings are verified by tests. The lightning performance calculation after the installation of parallel gap device is carried out. Through optimization of the electrical parameters and dimensions of the gap, the samples are developed and used in five 110 kV transmission lines. The operation situation of the 110 kV line parallel gap lightning protection of composite insulator is introduced. The results show that the designs of the parallel gap for 110 kV transmission line composite insulators meet the requirements. The parallel gap is in good on-site operation condition.