考虑频率安全约束的储能-电网联合规划

Energy Storage-grid Joint Planning Considering Frequency Safety Constraints

大规模的可再生能源并网使得电网内传统机组占比减小,惯性水平降低,电网的频率稳定性面临严重挑战。储能作为一种优质的调频资源,其调频时的高额注入功率会改变系统原有潮流,可能导致部分线路功率越限,因此提出了考虑系统潮流约束的“储能-输电网”联合规划模型。首先分析系统频率最大偏差与储能装机功率以及机组停运功率的关系,对系统内不同故障下的储能需求进行估计;然后以储能与输电线路扩建总成本最小为目标,建立考虑潮流约束的储能与输电线路扩建联合规划模型;最后基于修正的IEEE-39节点系统进行算例验证。结果表明相比于传统的单一储能规划,“储-输”联合规划具有更优的技术经济性,储能布点数目以及储能成本对规划结果影响较大。

The large-scale renewable energy has reduced the proportion of traditional units in the grid and the inertia level,and the frequency stability of the grid is facing serious challenges.As a high-quality frequency modulation resource,the high injection power of energy storage during frequency modulation will change the original power flow and may cause the power of some lines to exceed the limit.This paper proposes a joint planning of energy storage and transmission line considering power flow constraints.Firstly,the relationship between the maximum deviation of the frequency and the installed power of energy storage and the outage power of the unit is analysed,and the energy storage demand under different faults is estimated;then,with the goal of minimizing the cost of energy storage and transmission line expansion,a joint planning model of energy storage and transmission line expansion considering power flow constraints is established.Finally,the joint planning model was verified based on the revised IEEE-39 system.The results show that compared with the traditional single energy storage planning,the“storage-transmission”joint planning has better technical and economic advantages.The number of energy storage locations and the cost of energy storage have a greater impact on the results.