水电送出电网直流承载能力评估及提升措施优化

Evaluation and improvement measures for optimization of DC carrying capacity in a hydropower sending power grid

为了量化水电送出电网单一直流及直流群承载能力,提高送端电网清洁能源消纳水平,提出送端电网直流承载能力评估及提升方法。首先,分析直流承载能力受潮流组织、频率稳定、电压稳定、超低频振荡影响的特性,提出受安全性约束的直流承载能力计算方法。在此基础上,量化不同工况和故障下电网的运行风险,构建规划措施优选模型。最后通过对投资收益最大措施的搜索,实现电力规划与运行的协调。实际电网仿真结果表明,该方法能够为措施的选型、布点提供参考,最大程度提高直流承载能力。

To quantify single DC and DC group carrying capacity and improve the absorption capacity of clean energy in a hydropower sending power grid, this paper puts forward a method to evaluate and improve the DC carrying capacity. First, the characteristics of DC carrying capacity affected by power flow organization, frequency stability, voltage stability and ultra-low frequency oscillation are analyzed. A calculation method for DC carrying capacity with security constraints is proposed. Operational risks of the grid under different operating conditions and faults are quantified, and an optimization model of planning measures is established. Finally, the planning and operation of a power system are coordinated through the search for maximum investment benefit measures. Simulation results on a practical power system show the method can provide a reference for measure selection and distribution, and improve DC carrying capacity to the greatest extent.