关键词: 输电线路, 220 kV, 开断改接, 方案设计

Abstract: The maximum load of 220 kV Gang-yu substation and 220 kV Xin-gang substation are up to 180 MW and 170 MW respectively. Both substations are serially connected to 220 kV Yu-fu line and Tang-xin line. In case that one of the 220 kV Tang-xin line and Yu-fu lines has been tripped after fault, the rest will run both 220 kV Gang-yu substation and 220 kV Xin-gang substation, and the maximum load may be over 350 MW. The permissible currents of 220 kV Yu-fu line, Tang-xin line are 845 A. As a result, it will cause the current surpassing the permission of the line over 12%. Consequently, the proposal which reconnects the lines after the crisscross lines are unfolded and makes two new lines, one of which is from 220 kV Shen-yu substation to Gang-yu substation and the another is from 220 kV Xin-gang substation to Fu-shan substation is developed. According to this proposal’s computation, there are no negative effects on the power flow, stability under the N-1 operation condition of grid. However, there are numbers of negative influences on grid during the project construction because the 220 kV Shen-fu line, Yu-xin line and Xia-sha line must be cut off simultaneously. For this reason, three new proposals are developed. By technical and economic comparison of the proposals, the proposal of T-link on another side of the one-tower double-circuits is chosen as the optimal one to be applied to supply the peak load in summer.

Key words: transmission line, 220 kV, unfold-reconnection, embodiment design