考虑随机扰动风险的新能源并网调度模型与优化方法研究

With increasing grid-connected capacity of new energy, stochastic feature of output power for new energy aggravates local fault of power network which leads to cascading failure and finally causes large scale blackout. This study aims to power system dispatch strategies considering stochastic disturbance risk of new energy. Firstly, fault chain model of cascading failure will be formulated to simulate cascading dynamic diffusion process of line overload failure, while cascading failure risk associated with line overload severity function will be assessed. Secondly, cascading failure risk will be incorporated to the dispatch model with risk control factor. A power system dispatch model with cascading failure risk will be formulated, while effects and mechanisms of relative parameters on dispatch strategies will be investigated. Finally, in order to solve large-scale complex dispatch problem, analytical target cascading method will be introduced to perform hierarchical decomposition to realize the coordination and optimization of economy and risk of power system dispatch. Specially, this study is oriented to complex large power grid with stochastic and cascading features. Results could develop the power system optimal dispatch and cascading failure risk management method, and provide decision basis for power dispatching and operation management, as well as resource distribution optimization.

随着新能源并网规模不断增大，新能源出力随机性对局部电网故障起到推波助澜作用，诱发级联失效，最终导致大面积停电事故。针对考虑新能源随机扰动风险影响的电力调度决策问题，本项目首先建立级联失效事故链模型，模拟系统线路过载失效的级联动态传播过程，用线路过负荷严重度函数度量级联失效风险，进行风险评估；其次，引入风险控制因子，将级联失效风险纳入调度模型优化指标中，构建考虑级联失效风险的电力系统调度模型，研究影响调度策略相关参数的作用机理；最后，对于复杂大规模调度问题求解难题，引入目标级联法对其进行分层分解，实现电力调度经济性与风险性综合协调优化。特别地，本研究是面向复杂大电网随机、级联特征进行建模。研究成果可望丰富电力优化调度以及级联失效风险管理相关理论和方法，为电力调度运行管理和资源优化配置提供决策依据和政策建议。

气候变化引发的极端天气和新能源并网带来的随机扰动会引发电力系统级联失效，导致大面积停电事故。针对考虑电网级联失效风险的电力调度决策问题，本项目模拟级联失效线路故障概率和电网故障演变，评估电网级联失效风险，提出一套计及潮流熵和电网拓扑结构的电力调度模型与优化方法，结果表明控制线路负载率能有效减小切负荷量以及隐藏事故发生概率，改变网络拓扑结构能缓解系统输电阻塞，降低大停电风险，调度方法提高了系统应对极端事件的响应能力，为电力调度运行管理提供技术支持。电力系统韧性水平在应对极端天气和随机扰动事件发挥重要作用，韧性曲线是评估电力系统韧性水平的重要工具。本项目在级联失效风险评估和电力调度优化模型基础上，提出一套电力系统韧性评估框架，验证调度方法的有效性，评估电力系统韧性，并重新定义电力系统韧性曲线，刻画了传统电力系统和韧性电力系统在扰动前准备、吸收扰动、抵御扰动、扰动中响应、扰动后恢复等六个阶段以及三种系统稳定状态，为电力系统韧性评估及提升提供了量化依据。