基于光伏减载的电力系统紧急降风险控制方法

光伏发电系统通常运行于最大功率点,难以在紧急条件下为电网提供功率支撑。受制于建设和运行成本,储能的大规模应用还难以实现,同步发电机占比的降低使得含高比例光伏发电的电网安全风险不断增加。为此,分析了光伏发电系统的功率特性和稳定运行条件,提出了通过光伏减载运行预留备用功率从而为电网提供紧急功率支撑的思想。进而分析了协议发电成本和风险成本的关系,建立了以同步发电机启停机计划、备用容量和光伏减载量为决策变量的两阶段降风险发电调度优化模型。提出了考虑光伏减载运行的电力系统降风险优化调度方法。最后利用IEEE RTS 24节点系统验证了方法的正确性。算例分析表明,该方法能够在降低电网功率不平衡风险的前提下获得最优的经济性,具有较好的实用性。

A risk-reduction emergency control method of a power system based on photovoltaic power reserve

Photovoltaic (PV) power generation systems usually operate at the maximum power point, and it is difficult for them to provide power support for the grid under emergency conditions. Constrained by construction and operating costs, large-scale applications of energy storage systems are still difficult to achieve. The reduction in the proportion of Synchronous Generators (SG) has increased the security risks of power grids with a high proportion of PV power generation. The power characteristics and stable operating conditions of a PV power generation system are analyzed, and a control principle based on PV power reserve is proposed to provide emergency power support for the grid. The relationship between the agreed power generation cost and the risk cost is analyzed. A two-stage risk reduction power generation optimization scheduling method is established with a start-up and shutdown plan of SG, reserve capacity and PV power reserve as decision variables. A power system risk reduction optimization scheduling method taking into account the PV power reserve is proposed. Finally, the correctness of the proposed method is validated on the IEEE RTS 24-node system. The case study demonstrates that the proposed method is the most economical when reducing the risk of power imbalance in the power grid and has good practicability. This work is supported by the Science and Technology Project of State Grid Corporation of China (No. SGSW0000DKJS1900097).