海上深水区风电场并网的空间布局优化——以粤东地区为例

海上深水区风电场具有水深深、离岸远、规模大的特点,其并网空间布局的合理规划直接关系到投资成本和用海效率,而现有研究多停留于二维平面,精度有待提高。从风电汇集至岛屿再送出的设想出发,建立深水区风电场并网的三维空间布局优化设计模型,以粤东深水区风电场为例进行分析。研究表明：（1）深水区风电场并网需要考虑海底地形因素,尽管研究范围坡度很小,优化方案的电缆总长度还比二维平面计算结果长约5%;（2）汇集输电的方式能有效减少用海面积、降低总投资成本,其中征海面积、总投资成本减幅最大均可达65%;（3）不同输电方式的电缆成本越低,空间布局越接近以岛屿为中心的辐射状,随岛屿数量增加区别逐渐减小,220 kV交流、500 kV交流、±320 kV直流电缆成本依次减小,1个岛屿时对应方案的岛屿与汇集中心距离分别为38 km、27 km、9 km,4个岛屿时分别降至19 km、19 km、5 km。

Research on spatial layout optimization of offshore wind farms integration in deep-water area: Taking Eastern Guangdong as an example

Offshore wind farms in deep-water area are characterized by great water depth, far from shore, and large scale. The reasonable planning of transmission spatial layout is directly related to investment cost and efficiency of sea use. And the calculation method of existing research only focused on two-dimensional (2D) plane, and the accuracy needs to be improved. In this paper, to draw a lesson from the idea of wind power gathering to islands and then sending out, a three-dimensional (3D) spatial layout optimization design model for offshore wind farms integration in deep-water area is established, and the wind farms in deep-water area of Eastern Guangdong is taken as an example in this study. The results show that: (1) The seafloor topography should be taken into account in deep-water wind farm integration. Although the sea bottom slope in the study area is very small, the total cable length of the optimized schemes is about 5% longer than that of the 2D plane. (2) The method of wind power gathering to islands and then sending out can effectively reduce the sea-area used and the total investment cost. And the largest reduction of sea-area used and total investment cost can reach 65%. (3) The lower the cable cost per unit capacity of different transmission modes, the closer the design scheme to the island-centered radiation pattern. The difference gradually decreases as the number of islands increases. The per unit capacity cost of the cable used for 220 kV alternating current (AC), 500 kV AC and ±320 kV direct current (DC) decreases in turn. When there is one island, the distance between the island and the collection center of the corresponding scheme is 38 km, 27 km, and 9 km, respectively. And when there are four islands, the distance is reduced to 19 km, 19 km, and 5 km, respectively.