海底交直流电缆输电系统经济性比较

Economic Comparison of AC/DC Power Transmission System for Submarine Cables

针对海底电缆输电方式的选择问题,运用现金流折现模型,从经济层面对交流输电系统和直流输电系统进行比较。分别从设备投资成本、维护成本和损耗费用3个方面对海底交直流电缆输电系统的成本进行了探讨,给出了各部分成本的计算方法。以海底电缆连接海上风力发电场和内陆电网为基本模型,对不同输电距离下海底交直流电缆输电系统的经济性进行了比较,得到了不同输电距离下交直流系统的经济性比较结果。研究结果表明:当输电距离较短时,交流海缆输电系统经济性优于直流海缆输电系统;当输电距离大于临界值时,直流海缆输电系统比交流海缆输电系统更经济。

In order to select a suitable w ay for submarine pow er transmission system w ith cables,discounted cash flow model w as used to compare DC system and AC system from an economic perspective. The costs of DC / AC submarine transmission system w ere analyzed from three aspects： investment cost,maintenance cost and loss cost,and the calculation methods of each kind of cost w ere presented. In the case of submarine cable system connecting an offshore w ind farm and onshore grid, the economies of DC / AC submarine transmission systems w ith different transmission distances w ere compared,and the comparison results w ere obtained. The results indicate that the cost of DC submarine transmission system is higher than AC submarine transmission system w hen transmission distance is short,w hile in the case that the distance is beyond a certain level,DC submarine transmission system w ill have economic advantage.