Abstract In general, the seasonal characteristics of small hydropower (SHP) especially the power transmission during the summer flood season would lead to the steady overvoltage of the distribution network. In order to suppress this steady overvoltage, a strategy for coordinated cooperation between generator phase-in operation and shunt reactors which can be called cooperative control is proposed. The distribution network of SHP stations connected to the 35 kV Bantao substation in southern Shaanxi is taken as an example to study the mechanism of overvoltage after the SHP is connected to the grid. A distribution network model with SHP units is established. Based on the model, the effect of separately installing shunt reactors on the node voltage is studied in the case of generator lag phase operation and the influence of the operation mode of SHP unit on the node voltage is also analyzed separately. Finally, the improvement measures of cooperative control between the generator phase-in operation and the parallel reactors are analyzed by simulation. Results are presented to verify the improvement measures that can effectively restrain the overvoltage of the distribution network in the SHP area.

中文翻译：

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小水电配电网过电压协同控制策略分析

摘要 一般而言，小水电的季节性特征，特别是夏季汛期输电，会导致配电网稳定过电压。为了抑制这种稳态过电压，提出了一种发电机并网运行与并联电抗器协调配合的策略，称为协同控制。以陕南35kV板陶变电站接入的小水电站配电网为例，研究小水电并网后的过电压机理。建立了具有小水电机组的配电网模型。基于模型，研究了在发电机滞后相运行情况下单独安装并联电抗器对节点电压的影响，并单独分析了小水电机组运行方式对节点电压的影响。最后，通过仿真分析了发电机并网运行与并联电抗器协同控制的改进措施。结果表明，改进措施可以有效抑制小水电地区配电网过电压。