促进跨区新能源消纳的直流联络线功率优化模型及分析

提出了一种考虑直流联络线功率阶梯化运行、送端电网与多个受端电网跨区协调的常规能源与新能源联合优化的发电计划模型。建立了直流联络线功率阶梯化运行的数学模型,该模型满足直流功率调整的各项特性要求,包括直流功率阶梯化、相邻时段不可反向调整、稳定运行持续时间、日交换电量不变等约束,既充分发挥了直流联络线可灵活调节的特点,又避免了高压直流换流设备的频繁转换,提高了直流联络线计划的可执行性。同时,该模型可考虑多个跨区互联电网间的多条输电通道,以及送受端电网间的系统负荷互补性和新能源接纳能力,实现了送受端电网间的协调调度,促进新能源在更大空间范围内消纳。基于国内某跨区互联电网的实际数据,验证了所提模型的有效性。

Power Optimization Model and Analysis of HVDC Tie-line for Promoting Integration of Inter-regional Renewable Energy Accommodation

A generation scheduling model for joint optimization of conventional energy and renewable energy is proposed, in which the high-voltage direct-current(HVDC)tie-line power operation with a stair-like power curve and the inter-regional coordination of a sending system and multiple receiving power systems are taken into consideration. A mathematical model for the HVDC tie-line power operation is developed, which meets various constraints on tie-line power adjustment, including the stair-like HVDC power curve constraint, the constraint that no adjustment in the opposite direction of the tie-line power shall be made within an adjacent time interval, the stable operation duration constraint on tie-line power, and the constant daily electricity constraint. The model not only makes full use of the flexible adjustment characteristics of HVDC tie-line power, but also avoids the frequent conversion of HVDC converter equipment, making the HVDC tie-line schedule more executable. The model can deal with multiple HVDC transmission channels between multiple inter-regional interconnected power grids, as well as the system load complementarity and the renewable energy acceptance between sending and receiving power systems. Then coordinated scheduling between sending and receiving power systems can be achieved, renewable energy accommodation in a wider area promoted. Case studies are conducted based on the actual operational data of an inter-regional interconnected power grid in China. The results have validated the effectiveness of the model proposed.