| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1995: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1994: ¥1,300,000 (Direct Cost: ¥1,300,000)
|
|---|
| Research Abstract |
The project aimed to develop the Transient Electromagnetic Field Propagation Code (TEPCO) which can analyze surge phenomena in transmission lines by Moment Method. The method deals the time response in same time range, and linear resistance and inductive element flashover model which is a typical nonlinear phenomena in lightning surge. To verify the code, we studied how the lightning surge travels into a substation by experimentally in a miniature model taking notice of the relations between the power line currents, ground wire currents and gantry currents. If we insert the resistance 400OMEGA between ground wire and gantry, the surge current on the power lines at the entry of the substation shows the peak value less than a half of the peak in the resistance free. The power line current flows in the opposite direction with the ground wire current. It is also investigated the multiplication effects of ground wire to prevent back flashover in case of double and triple ground wires. In the cause of the induction by the ground wire current, the power line current in triple ground wires increases 15% greater than the double ground wires. However, the voltage between are hones in triple decreases contrariwise. Therefore, the multiplication of ground wire is effective for the avoidance of back flashover. As the relative geometrical relations influence the lightning surge on the power lines, it is necessary to account the mutual coupling between the power lines and gantry in the analysis of the surge traveling into a substation.
|
