考虑过电压因素时分布式光伏电源的准入容量

The maximum power of distributed PV generation according to over-voltage in distribution network

大量分布式光伏接入配电网可能引起电网电压偏差越限。首先建立了不同分布规律下负荷引起的电压损失计算模型和光伏引起的电压抬升计算模型,在母线电压偏差可达标准上限的前提下,导出了线路不出现过电压时允许接入的最大光伏容量。针对10 kV典型线路,给出了光伏与负荷相同分布规律下的最大光伏渗透率和不引起过电压条件下的馈线首端电压裕度。结果表明,架空线路比电缆线路可接纳更大的光伏容量,利用光伏电源的调压作用可防止过电压,降低母线电压可允许接入更多光伏容量。

Large amount of distributed PV generators connected into distribution feeder will cause the out-of-limit of voltage deviation. The calculation models of voltage drop caused by loads and voltage rise caused by PV generator are established under different loads or PV distribution along the line, and the maximum PV power injected into the feeder without causing over-voltages is proposed assuming the bus voltage deviation is reaching the upper limit. The maximum PV penetration level＇ of lO kV typical distribution line is derived under the condition that PV generation is of the same power distribution rule with load, and the voltage margin at the head end of feeder without causing over-voltage is provided. The analysis results show that over-head line can carry more PV power than cable, over-voltage will be avoided by controlling the PV power according to the connection point voltage, and suitably lowering the bus voltage will also allow more PV connecting to the feeder.