暂态频率约束下考虑新能源最优减载的机组组合双层优化策略

Two-layer Optimization Strategy for Unit Commitment with Transient Frequency Constraint Considering Optimized Reserve of Renewable Energy

大规模风、光等新能源并网引起的惯量降低给新型电力系统安全运行带来了新的挑战,其中尤为突出的是暂态频率安全。文章在充分利用新能源频率支撑作用的基础上,提出了暂态频率约束的机组组合双层优化策略。构建了计及新能源场/站频率支撑的新型电力系统频率响应模型,推导了暂态频率特征量的解析化表达式,进而在传统机组组合模型的基础上,构建了考虑动态频率约束的机组组合优化模型;引入原子搜索算法,协同考虑频率支撑的新能源最优减载优化与机组组合优化,建立了双层优化策略。以含风电及光伏的10机系统为例进行计算分析,结果验证了所提方法的有效性和可行性。

The inertia reduction caused by the integration of large-scale wind power, PV, and other renewable energy sources has brought new challenges to the safe operation of new type power systems, especially transient frequency safety. In this paper, on the basis of making full use of the frequency support of new energy sources, a two-layer optimization strategy for unit combinations with transient frequency constraints is proposed. A new frequency-response model of the power system considering the frequency support of the new energy station is constructed, and the analytical expression of the transient frequency characteristic quantity is deduced. Then, on the basis of the traditional unit combination model, a unit combination optimization model considering the dynamic frequency constraint is constructed. Introducing an atomic search algorithm, synergistically considering frequency support for optimal load shedding optimization of new energy sources, and unit combination optimization, a two-layer optimization strategy is established. Taking a 10-machine system including PV and wind power as an example, the calculation and analysis are carried out, and the results verify the effectiveness and feasibility of the method in this paper.