含燃气发电综合能源系统风电消纳能力评估

Wind Power Accommodation Capability Assessment of Integrated Energy Systems With Gas-fired Units

随着风电等出力波动且不确定的新能源规模化发展,其有效消纳成为重要难题,具有快速调节能力的燃气机组将在风电消纳中扮演重要角色。现有风电消纳能力评估工作大多仅以电力系统视角展开,并未充分考虑天然气、煤炭等发电资源约束对评估结果的影响。为此,该文提出一种电–气耦合综合能源系统风电消纳能力评估方法,计及燃气机组用气需求对天然气系统供气充裕性的影响,以不确定集合形式建模风电不确定性,并采用电力系统运行风险作为评估指标,优化风电可消纳区域。上述模型在数学上构成一类两阶段鲁棒优化模型,为处理天然气网络方程中非线性项,采用分段线性化方法,因而在第二阶段内层极小化问题中引入布尔型变量,并应用嵌套C&CG算法求解。算例分析在2种不同规模的测试系统展开,验证了在风电消纳能力评估时合理建模天然气系统的必要性,并分析了风电出力预测精度、弃风与切负荷罚系数、系统规模等因素对评估结果和方法的影响。

With rapid development of variable and uncertain renewable energy,such as wind power generation,their effective accommodation become a vital problem,where fast-response gas-fired units would play an important role.Most existing wind power accommodation capacity evaluation works are carried out from the perspective of power systems without fully considering the impacts of natural gas,coal and other power generation resource constraints.To this end,this paper proposed a method to evaluate the wind power accommodation ability of the integrated electric-gas systems,where the gas supply adequacy for gas-fired units were considered by the modelling of natural gas systems.The uncertainties of wind power were depicted by uncertainty sets,and the operating risk of power systems was employed to optimize the wind power admissible region.The proposed model constitutes a two-stage robust optimization model mathematically.In order to deal with the non-linear terms in natural gas system constraints,the piecewise linearization method was adopted.Therefore,Boolean variables were introduced into the second-stage inner minimization problem and the nested-C&CG algorithm was applied to solve the proposed two-stage model.The example analysis was carried out in two different scale test systems,verifying the necessity of modeling natural gas system in wind power absorption capacity evaluation.Meanwhile,the impacts of the prediction accuracy of wind power outputs,penalty efficient of wind curtailment and load shedding,and system scale on the evaluation results and methods performances were analyzed.