火电机组灵活性改造与输电网规划多阶段联合决策方法

Multi-stage Joint Planning Decision-making for Transmission Network and Thermal Power Unit Flexibility Reformation

大规模风电并网对电力系统灵活性提出了很高的要求。针对大规模风电并网背景下的消纳问题提出了一种火电机组灵活性改造与输电网规划多阶段联合决策方法。通过将火电机组灵活性改造纳入输电网规划优化决策,统筹优化系统灵活性及传输能力,促进大规模风电并网消纳。基于规划周期内负荷功率预测曲线,并计及风电时序出力不确定性情景,以输电网建设投资成本、火电机组灵活性改造成本以及发电总成本、弃风电成本折现值之和最小为目标,以系统正常运行状态以及N-1事故状态下安全运行要求为约束条件构建火电机组灵活性改造与输电网规划多阶段联合优化决策模型,并通过大M法将所提模型转换为混合整数线性规划模型进行快速求解。算例分析验证了所提多阶段联合规划决策方法的有效性和经济效益。

The flexibility of power systems is facing serious challenges with increasing wind power integration.In response to the wind power accommodation problem with large-scale wind power integration,this paper proposes a multi-stage joint planning decision-making method for transmission network and thermal power unit flexibility reformation.Through the integration of flexibility reformation schemes of thermal power units into a transmission planning optimization model,the flexibility resources and transmission capability of power systems are optimized to promote wind power accommodation.Based on the forecasted time-sequence characteristics of load and uncertain wind power scenarios,a novel multi-stage joint planning optimization model is built to minimize the total discount values of the investment cost of power grid construction and thermal power unit flexibility reformation,as well as the generation cost and wind power curtailment cost by considering the uncertainty of wind power output,in which the operation security constraints under normal and N-1 contingency conditions must be respected.The proposed model is converted into an easily solvable mixed-integer linear planning model using the big M method.Case studies were conducted to illustrate the effectiveness and economic efficiency of the proposed multi-stage joint planning method.