考虑频率约束的含储能低惯量电网机组组合和经济调度

Frequency constrained unit commitment and economic dispatch with storage in low-inertia power system

电网中新能源的大规模接入使传统火力机组逐步被淘汰,电力系统惯性逐渐降低,频率问题日益严重。储能是平抑新能源和负荷带来波动性问题的重要手段。本文针对含储能低惯量电网中的频率问题展开研究,提出考虑频率约束的含储能低惯量电网中的机组组合和经济调度模型。首先将表示频率指标的非线性约束线性化,然后采用模型预测控制方法将储能模型引入到传统的机组组合和经济调度模型当中,最后用场景化的方式处理风电的不确定性。算例表明所提模型能够使系统在扰动情况下保证频率指标在允许范围内,且机组和储能能够处于经济的运行状态。

As renewable energy sources are widely connected to the grid,traditional generators are gradually being phased out,which gradually turns power system into a low-inertia system with frequency problems.Energy storage can mitigate the system’s highly volatile loads and new energy.Therefore,this paper proposes a unit commitment and economic dispatch model in a low-inertia power system with energy storage considering frequency constraints.First,the nonlinear constraint representing the frequency index is linearized,and then the model prediction control method is adopted to incorporate the energy storage model into the traditional unit commitment and economic dispatch model.We finally deal with the uncertainty of wind power in a scenario-based manner.Case study shows that the proposed model can ensure that the key frequency indexes are within the allowable range when power system is disturbed,while the generator and storage can be better dispatched.