含风电场电力系统机组组合的模糊机会约束决策模型

A Fuzzy Chance Constrained Decision Model for Unit Commitment of Power Grid Containing Large-Scale Wind Farm

风电出力的模糊性使传统确定性的调度可行域出现了模糊变量,模糊机组组合的决策结果需要兼顾经济性和系统的置信水平。研究了考虑风电模糊置信水平的机组组合问题。建立模型时,将风电出力的模糊性体现为误差的模糊性,基于可信性理论推导了风电预测误差的可信性分布函数,并据此建立了旋转备用的模糊机会约束条件,进一步得到了机组组合的模糊机会约束模型。求解模型时,将模糊机会约束转化为其清晰等价类,避免了繁琐的模糊模拟过程,并采用混合整数线性规划方法求解。算例分析表明了文中方法比传统确定性模型更能体现风电模糊性对决策结果的影响,并且适用于大规模系统。

The fuzziness of wind power generation brings fuzzy variables into feasible zone of traditional power dispatching based on certainty, so it is necessary to consider both economy and confidence level of power system operation in the decision results of fuzzy unit commitment. In this paper the unit commitment considering fuzzy confidence level of wind power generation is researched. During the modeling, the fuzziness of wind power output is incarnated as the fuzziness of prediction error, and based on credibility theory the credibility distribution function of prediction error of wind power generation is derived, and on this basis the fuzzy chance constraints for spinning reserve are established and then a fuzzy chance constrained model for unit commitment is obtained. To solve the proposed model, the fuzzy chance constraints are turned into their equivalent forms to avoid cumbersome fuzzy simulation process, so the proposed model can be solved by mixed integer linear programming algorithm. Simulation of IEEE 118-bus system shows that the proposed method can incarnate the impact of fuzziness of wind power generation on decision results more clearly, and it is proved that the proposed method is suitable to unit commitment of large-scale power grid with fuzzy parameters.