中文摘要：

在大规模新能源接入的互联电网中，充分利用直流联络线的调整能力，将极大地促进更大空间范围内的新能源消纳。为此，文中提出了一种以直流联络线运行方式优化提升新能源消纳能力的新模式。该模式将联络线交换功率作为可优化的资源，在满足联络线功率调整各种特性要求的前提下，通过联络线功率的调整促进互联电网的新能源消纳。建立了直流联络线运行优化的数学模型，考虑了联络线功率调整的各类约束条件，包括日交换电量不变、联络线功率曲线阶梯化、短时间内不得反方向调节等。基于国内某跨区直流输电通道的实际运行数据开展了算例分析，计算结果表明了所提出模式的有效性。

英文摘要：

In the interconnected power grid with large-scale renewable energy,the renewable energy can be accommodated in a wider area if the adjustment capability of high-voltage direct-current （HVDC） tie-lines is well utilized.To this end,a new mode of HVDC tie-line operation optimization for increasing the capability of renewable energy accommodation is proposed.In the mode,the tie-line power is viewed as a resource to be optimized.On the premise of meeting all the requirements of the tie-line power adjustment,the renewable energy accommodation in the interconnected power grid can be improved by adjusting the tie-line power.A mathematical model of the HVDC tie-line operation optimization is developed with consideration given to various constraints on tie-line power adjustment,including the daily energy limit,the stair-like tie-line power curve constraint, and the constraint that no adjustment in the opposite direction of the tie-line power shall be made within a short period of time. Case studies are conducted based on the actual operational data of a transregional HVDC transmission channel in China.The results have validated the effectiveness of the mode proposed.