本論文以電磁理論的方法分析含有多種地網的接地系統之雷擊特性,本文是以台北捷運系統木柵機廠的接地系統為研究對象,該系統具有七大地網,針對其中某地網遭受雷擊時,各地網的地電位湧昇、地面電位、地網電位差、步間電壓及接觸電壓進行分析,並評估人員及設備可能遭受的危害,這些分析及評估將分別考慮地網相連與不相連兩種狀況。研究結果顯示地網相連時,被雷擊的地網其地電位湧昇、步間電壓、接觸電壓及地網電位差將小幅降低,此對設備的保護及被雷擊地網上的人員安全雖稍有正面的貢獻,不過地網相連也稍會提昇其他非雷擊地網的地電位湧昇、步間電壓與接觸電壓,評估結果無論地網相連與否,一旦雷擊發生時都難以確保人員與設備安全,必須加強各種雷擊防護措施,本研究對過去所提出的各種雷擊防護措施加以整理、列出以供參考。
In this thesis, the lightning characteristics of large grounding system with multi-grid are analyzed based on the electromagnetic theory. The study is aimed to the grounding system in the Mucha factory of Taipei-Rapid-Transit System (TRTS) which is composed of seven ground grids. To study the lightning characteristics of this grounding system, the ground potential rises (GPRs), ground surface potentials, ground potential differences (GPDs) between different grids, step voltages and touch voltages on each grid when the lightning is striking on one of the grids is analyzed and the hazards to personnel and equipments are evaluated. The study will consider that all the grids are connected together and disconnected from each other, respectively. The study results have shown that the GPR, GPD and touch voltages on the grid to be stricken by lightning will be reduced with small degree when all the grids are connected together. These results will contribute to the protections of equipments and the safety of personnel on the grid to be stricken by lightning, but the GPR of step voltage and touch voltages on other grids without lightning striking will be slightly risen. In summary, whether all the grids are connected together or not, the protection measures are still required to enhance the personnel and equipments to protect against lightning. Many protection measures had been proposed by the literatures. This thesis will integrate then and list out for application references.