光-蓄-储混合储能系统灵活性提升与容量规划

Capacity optimization and flexibility enhancement of photovoltaic-battery-pumped hybrid storage system

抽水蓄能电站是当前发展最为成熟、配置容量最大的储能设施,但其功率变化速率较慢,调节灵活性较为匮乏。电化学储能是当前发展最快的储能形式,具备灵活的功率调节能力。文中的目的在于构建光-蓄-储混合储能系统,通过不同储能设施的特性互补,大幅提升抽水蓄能电站的运行灵活性。文中基于抽水蓄能的功率振荡区间描述机组的功率调节能力,并根据单台机组的功率调节能力以及多台机组的组合方式定义抽水蓄能的灵活性。考虑灵活性约束以及提升机组运行寿命的需求,建立光-蓄-储混合储能系统的容量规划模型。以山东某抽水蓄能站为例,进行实例分析。结果表明,配置额定功率等于抽水蓄能容量10%的电化学储能系统可以提升40%的蓄-储系统灵活性,减少14%的机组发电启动次数。但在当前的两部制电价下,峰谷电价差需要超过0.5元/(kW·h)时电化学储能系统才具备盈利空间。

Pumped hydro storage(PHS)is the most mature storage technology with the largest installed capacity.However,its power regulation rate is slow,and its adjustment flexibility is relatively lacking.Electrochemical storage,which is currently the fastest developing storage equipment,provides capability of flexible power regulation.A photovoltaic-battery-pumped hybrid energy storage system is constructed in this paper.The goal is to improve the flexibility of PHS by utilizling the complementary characteristics of different storage facilities.The power regulation capability of the unit based on the power oscillation interval description of pumped storage is described,and further defines the flexibility of PHS according to the regulation of single unit and the unit-commitmen of multiple units.Considering the flexibility enhancing constraints and the demand to improve the operational lifespan of PHS,a capacity optimization strategy for the battery in hybrid energy storage system is established.A case study is conducted using a PHS in Shandong province as an example.The findings reveal that configuring an electrochemical energy storage system with a rated power equal to 10%of the PHS capacity can improve the flexibility of the storage system by about 40%,and reduce generation start-up times by 14%.However,under the current electricity pricing structure,the peak-valley price gap needs to surplus 0.5 yuan per kW·h for the electrochemical storage facility to become profitable.