摘要
柔性直流互联技术可有效改善电网电能质量、增强供电可靠性、提升新能源消纳水平。采用主从控制的柔性直流互联系统中,负荷突增和新能源出力短时波动等突发工况易导致主站实际功率超过其容量。传统功率限幅或调度方法难以及时平抑功率波动,进而导致直流侧电压异常,威胁系统正常运行。为此,文中提出一种计及主站容量裕度的主从控制策略。该策略优化了主站的运行机制,将容量裕度因素纳入主站运行模式中,调整了主站电压环的环路结构与变量定义,并增加了基于过容功率的闭合抑制环路,保障了主站对直流母线电压的持续调节能力。由于主站在平衡系统功率时需要从站间的协调运行,因此文中在从站传统运行模式及原有调度基础上引入了从站间的功率支援机制,在系统功率平衡等约束条件下建立了系统经济损失最小、源储设备损耗最小的多目标优化模型,并利用非支配排序遗传算法-Ⅱ(non-dominated sorting genetic algorithm-Ⅱ,NSGA-Ⅱ)对优化模型进行快速求解。最后通过仿真验证了所提策略能有效防止主站过容,保障柔性直流互联系统稳定、高效运行。
The flexible DC interconnection technology can effectively improve the power quality of the power grid,and enhance the reliability of power supply,thus improving the level of new energy consumption.In a flexible DC interconnection system with master-slave control,sudden load increase and short-term fluctuation in new energy output are likely to cause the actual power of the master station to exceed its capacity.It is difficult to timely suppress power fluctuation through traditional power limiting or scheduling methods,which leads to abnormal DC side voltage and threatens the stable operation of the power system.Therefore,a master-slave control strategy that takes into account the capacity margin of the master station is proposed.The strategy optimizes the operation mechanism of the master station and incorporates the capacity margin factor into the operation mode of the master station to adjust the voltage of the master station.The loop structure and variable definition of the loop are added.A closed suppression loop based on overcapacity power is added,which ensures the continuous regulation ability of the main station to the DC bus voltage.Since the master station needs the coordinated operation among the slave stations when balancing the system power,a power support mechanism among the slave stations is introduced based on the traditional operation mode and original scheduling of the slave stations,and a system under the constraints of system power balance and other constraints is established.The multi-objective optimization model with the smallest system economic loss and the smallest source-storage equipment loss is established,and the non-dominated sorting genetic algorithm-Ⅱ(NSGA-Ⅱ)is used to solve the optimization model quickly.Finally,it is verified by simulation that the proposed strategy can effectively prevent the overcapacity of the master station and ensure the stable and efficient operation of the flexible DC interconnection system.
作者
王楚扬
张秋玥
张犁
WANG Chuyang;ZHANG Qiuyue;ZHANG Li(College of Energy and Electrical Engineering,Hohai University,Nanjing 211100,China)
出处
《电力工程技术》
北大核心
2023年第3期81-91,共11页
Electric Power Engineering Technology
基金
国家自然科学基金资助项目(52007052)。
关键词
柔性直流互联系统
主从控制
容量裕度
从站协同控制
功率支援
有功优化潮流
flexible DC interconnection system
master-slave control
power capacity margin
slave cooperative control
power support
optimal power flow
