双馈感应发电机参与调频的概率最优潮流模型

随着风电并网容量增加,风电机组部分取代同步机组,需要其参与调频以维持电网稳定性。现有电网经济调度研究,在考虑频率时往往忽略风电,或以风电功率代替具体风电机组。提出一种计及双馈感应发电机(DFIG)参与一次调频的概率最优潮流模型。计及风速预测误差概率特性,在优化目标中引入频率偏移,通过权重系数兼顾发电成本和频率偏移。引入DFIG内部约束,提出优化模型中DFIG参数的修正方法,实现DFIG与同步发电机共同参与一次调频。算例分析了DFIG参与调频效果、目标权重系数对优化结果的影响,给出了发电成本和频率偏移的概率特性,验证了所提模型的有效性。

Probabilistic Optimal Power Flow Model Considering Participation of Doubly-fed Induction Generators in Frequency Regulation

With an increase in wind power integration, wind turbine generators have partly replaced synchronous generators(SGs). So they are required to participate in frequency regulation to maintain system stability. The existing economic dispatch often ignores the wind power when considering frequency, or uses the bus power to replace specific wind turbine generators. A probabilistic optimal power flow(OPF)model with doubly-fed induction generators(DFIGs)participating in the primary frequency regulation is newly proposed. The frequency deviation due to wind speed forecast error is introduced to the optimization object. The generation cost and frequency deviation are coordinated by choosing the weighting coefficients. The inner constraints on the DFIGs are included, whose parameters are modified in the optimization model. Thus the DFIGs and the SGs undertake the primary frequency regulation together. The numerical analysis shows the effect of DFIGs participating in frequency regulation, the impact of the weighting coefficients on the optimization results, and the probabilistic characteristic of the generation cost and the frequency deviation, which validates the effectiveness of the proposed model.