东北电力技术

随着我国“双碳”战略与新型电力系统构建进程不断推进，光伏发电等分布式电源装机占比不断增加，由于光伏出力的强随机性和间歇性，大规模光伏电源无序并网导致配电网潮流出现大范围变化，配电网相继出现潮流倒送、电压双向越限及网损增加等问题，严重影响了配电网的安全、稳定、经济运行。首先，本文针对分布式光伏造成的电压、损耗等突出问题，建立分布式光伏接入系统电压偏差、损耗及功率因数关系方程，论证了分布式光伏出力、电压偏差及损耗之间的关系。其次，结合某10 kV线路实际运行数据，搭建ETAP时序潮流仿真模型，提出了分布式光伏电压越限综合治理方法。最后，通过试验仿真分析验证了所提治理方法的有效性，所提方法考虑了电网大小负荷及光伏出力特性，充分利用了逆变器无功调压能力，有效提升了配电网电压合格率水平，为分布式光伏电压越限治理提供理论和实践参考。

With the continuous promotion of China's “two-carbon” strategy and the construction process of new power systems, the installed proportion of distributed power sources such as photovoltaic power generation continues to increase.However, due to the strong randomness and intermittence of photovoltaic power output, large-scale photovoltaic power sources are disconnected, resulting in large-scale changes in the power flow of distribution network.The problems such as power flow backflow, voltage overstep, voltage fluctuation and network loss increase appear successively in distribution network, which seriously affect the safe, stable and economic operation of distribution network.Firstly, in view of the prominent problems of voltage and loss caused by distributed photovoltaic, it establishes the relationship equations of voltage deviation, loss and power factor in the distributed photovoltaic access system, and demonstrates the relationship among the output, voltage deviation and loss of distributed photovoltaic.Then, combined with the actual operation data of a 10 kV line, it builds the ETAP time-series power flow simulation model, and proposes the comprehensive treatment method of distributed photovoltaic voltage over-limit.Finally, it verifies the effectiveness of the proposed governance method through experimental simulation analysis.The proposed method considers both the size of the power grid load and the characteristics of photovoltaic output, fully utilizes the reactive power regulation capability of the inverter, improves the voltage qualification rate of the distribution network, and provides theoretical and practical references for the governance of voltage over-limit in distributed photovoltaic.