双重功率优化控制的规模化光伏并网电压越限研究

Research on Dual Power Optimal Control for Scaled Photovoltaic Grid-connected Voltage

针对大规模光伏发电系统在高功率输出时,常会导致配电网中低压馈线发生电压越限的问题。该文在分析低压馈线过电压产生机理后,提出一种新型主动功率优化控制策略来防止低压馈线过电压现象发生。该策略通过对大规模光伏系统接入配电网的最优潮流计算得到其电压分布和功率分布,然后保证低压馈线电压不越限条件上运用灵敏度矩阵精确分析能接收每个光伏系统的功率输出,多余功率通过潮流控制引到其他系统利用或输出到电网,可实现大规模光伏发电系统的最大输出,提高电网对新能源的消纳能力。最后,通过算例仿真和实验验证结果表明,新型主动功率优化策略不仅具备使馈线电压不越限的能力,还具有更低的功率损耗和更高的光伏利用效率,具有较好的应用前景。

According to the high output power of large scale photovoltaic power generation system, it may lead to over-voltage in distribution network. This paper analyzed the mechanism of over voltage in low voltage feeder voltage and put forward a new active power optimization control method to prevent the phenomenon of over-voltage in low voltage feeder. With this new strategy, we worked out the voltage and power distributions by the optimal power flow (OPF) of distribution network accessing to the large-scale PV system. Then, the sensitivity matrix was used to analyze the power output of each PV system accurately. And the redundant power was leaded into other systems, improving the consumptive capacity of power grid for new energy. Finally, the simulation and experimental results verifies that the new strategy of active power optimization and control not only has the ability of keeping the low voltage feeder voltage under its limit value, but also a lower power consumption and higher PV utilization efficiency. © 2016 Chin. Soc. for Elec. Eng.