基于短路比约束的受端电网新能源并网出力优化方法研究

Research on optimization method of new energy grid-connected output of the receiving power grid based on short-circuit ratio constraint

在大规模分布式新能源发电资源接入受端电网的情况下,如何能够在保证受端电网并网点处暂态电压稳定性的同时,优化受端电网新能源发电机组的出力,是须要解决的关键问题。文章研究一种基于短路比约束的受端电网新能源并网出力优化方法。首先,通过构建受端电网等效模型,分析分布式新能源发电机组接入后,受端电网暂态电压稳定性的影响因素;其次,结合短路比的物理含义,建立新能源电网并网短路比模型,并将其作为研究受端电网并网点暂态电压稳定性的关键指标;再次,以受端电网新能源弃电成本、火电机组运行成本最小为优化目标,考虑短路比等其他约束条件,建立受端电网新能源出力优化模型,并进行求解;最后,仿真验证所建立的模型,结果表明,优化模型可在一定程度上提高受端电网中新能源的出力水平。

In the case of large-scale distributed new energy power generation resources connected to the receiving power grid,how to ensure the stability of transient voltage at the receiving power grid junction point and optimize the output of the new energy generating units in the receiving power grid at the same time is the key problem to be solved.In this paper,an optimization method of new energy output based on short-circuit ratio constraint is studied.Firstly,by constructing the equivalent model of the receiving power grid,the factors affecting the transient voltage stability of the receiving power grid after the distributed new energy generating unit is connected are analyzed.Secondly,combined with the physical meaning of short-circuit ratio,the short-circuit ratio model of new energy grid is established,and it is used as a key index to study the transient voltage stability of the receiving power grid.Then,the new energy output optimization model of the receiving power grid is established with the minimum abandonment cost of the new energy and the operating cost of the thermal power unit as the optimization goal,and other constraints such as the short-circuit ratio are considered.Finally,the simulation verifies the model,and the results show that the optimized model can improve the output level of new energy in the receiving power grid to a certain extent.