大规模风电经直流外送的区域输电能力计算

摘要

大型风电基地风电消纳的可行方案是跨区域直接送至负荷中心进行消化,由此产生大规模风电远距离输电的问题,进而对区域间最大输电能力(Total Transfer Capability,TTC)的计算提出新需求.针对大规模风电经直流外送的区域输电能力计算,结合风火打捆直流外送方式,建立了风电经直流外送的区域间TTC计算模型,并采用交直流交替迭代连续潮流算法进行求解.采用改进的IEEE 39节点系统进行测试,对大规模风电经交、直流2种外送方式下的TTC进行对比计算,并讨论了不同风电场出力情况及风火打捆比例对TTC的影响.结果表明:在既定网架结构下,需要协调考虑风火打捆比例和线路容量,在尽可能多地接纳风电的同时,使系统获得最大输电能力.%For the digestion of wind power generated in the large wind power bases, the feasible option is transferring the power to the load center directly cross regions, yet the new transfer format gives rise to the long distance power transmission of the large wind farms, which necessitates new demands for calculation of the total transfer capability (TTC) across regions. Aiming at the calculation of the TTC of the trans -regional HVDC transmission system for large-sized wind farms, and based on the format of the bundled transmission format of both thermal and wind power, this paper establishes a TTC calculation model considering that wind power delivered to another region by HVDC and uses the continuation power flow (CPF) algorithm based on AC/DC alternate iteration to find solutions. The modified IEEE 39 —bus system is used for the test, the TTC through AC and HVDC paths is calculated respectively and the influence of the wind power output and wind/fire bundling ratio is also discussed. The results indicate that under the established grid structure, it's necessary to consider wind fire bundling proportion and line capacity coordinately to ensure the system can accept wind power as much as possible and obtain the maximum transfer capacity at the same time.