基于短路容量量化评估的大规模新能源直流送端电网运行方式优化方法  

Optimal method of operation modes for large-scale new energy DC sending-end power grid based on short circuit capacity quantitative assessment

作　　者：牛拴保 柯贤波 任冲 霍超 王智伟 张钢 卫琳 NIU Shuanbao;KE Xianbo;REN Chong;HUO Chao;WANG Zhiwei;ZHANG Gang;WEI Lin(School of Electrical Engineering,Xi’an Jiaotong University,Xi’an 710079,China;Northwest Branch of State Grid Corporation of China,Xi’an 710048,China)

机构地区：[1]西安交通大学电气工程学院,陕西西安710079 [2]国家电网公司西北分部,陕西西安710048

出　　处：《电力自动化设备》2021年第12期123-129,共7页Electric Power Automation Equipment

基　　金：国家电网公司总部科技项目(5100-202036013A-0-0-00)。

摘　　要：直流送端电网中需保证一定数量的常规机组提供短路容量以平抑电压波动,而开机容量过大将挤占新能源消纳空间,为电网运行方式优化带来了难题。对此,基于支路潮流法揭示了暂态过电压与直流母线短路容量的关系,推导出保证一定暂态过电压水平的最小母线短路容量的量化算法,提出了利用常规机组短路电流权重指数作为考虑短路容量约束的机组优化组合权重因子,给出了常规机组开机方式与各条直流短路容量需求之间的量化关联关系。基于该方法建立了考虑直流近区短路容量约束的机组组合优化模型,采用机组组合优化算法统筹考虑各种约束,优化机组开机方式,在保证安全稳定运行的基础上实现了新能源最大消纳。最后以西北某省级电网为例验证了所提方法的有效性及优越性。It is necessary for DC sending-end power grid to ensure that certain conventional units provide short circuit capacity to suppress voltage fluctuations.However,excessive start-up capacity will occupy the space of new energy consumption,which brings difficulties to optimal method of operation modes for power grid.Based on branch power flow method,the relationship between transient overvoltage and DC bus short circuit capacity is revealed,and the quantitative algorithm of minimum bus short circuit capacity of conventional unit to ensure a certain transient overvoltage level is derived.The weight index of short circuit cur rent is proposed as the weight factor of unit optimal combination considering the constraint of short circuit capacity.The quantitative relationship between the start-up mode of conventional units and the demand of DC short circuit capacity is given.Based on this method,a unit commitment optimal model considering the constraints of DC short circuit capacity is established,and the unit commitment optimization algorithm is adopted to consider all kinds of constraints to optimize the start-up mode of the units,so as to achieve the maximum consumption of new energy on the basis of ensuring operation safety.Finally,a provincial power grid in Northwest China is taken as an example to verify the effectiveness and superiority of the proposed method.

关 键 词：特高压直流 暂态过电压 短路容量 机组组合 优化 

分 类 号：TM721.1[电气工程—电力系统及自动化]