考虑可再生能源消纳的火电机组市场力评估

随着可再生能源并网比例的不断提升,实现其全额消纳会对火电机组的市场机会产生越来越大的冲击。针对这一现象,提出了火电机组综合市场力评估方法。考虑可再生能源发电并网下火电机组备用作用的强化,对传统市场力指标——Lerner指数进行修正,建立了反映火电机组在电量市场与备用市场综合市场力的改进Lerner指标;同时计及风电出力的不确定性,采用正态分布与拉普拉斯分布的联合概率密度函数更好地反映风电预测误差的尖峰厚尾特性,完善了备用需求的表达;以电量完全竞争作为假设前提,采用电量—备用联合优化模型模拟电力市场交易,进而完成对火电机组综合市场力的准确度量。以10机系统为例进行仿真计算,验证了改进指标的有效性并分析风电渗透率、风电预测精度等因素变化对火电机组综合市场力的影响。

Market Power Assessment of Thermal Power Units Considering Renewable Energy Consumption

With the increasing proportion of renewable energy connected to the grid, the realization of its full absorption will have an increasingly great impact on the market opportunities of thermal power units. In view of the issue, this paper presents a method for evaluating the comprehensive market power of thermal power units. Considering the enhancement of reserve use of thermal power units under the grid-connected renewable energy generation, the traditional market power index - Lerner index is revised, and an improved Lerner index reflecting the comprehensive market power of thermal power units in the electricity market and reserve market is established. Considering the uncertainty of wind power output, the joint probability density function of normal distribution and Laplace distribution is used to fit the peak and thick tail characteristics of wind power prediction errors, which improves the expression of reserve demand. On this basis, based on the assumption of complete electricity competition, the electricity-reserve joint optimization model is used to simulate electricity market transactions, and then the accurate measurement of the comprehensive market power of thermal power units is completed. Finally, a 10-unit system is taken as an example to verify the effectiveness of the improved indicators and analyze the impact of changes in wind power permeability, wind power prediction accuracy and other factors on the comprehensive market power of thermal power units.