考虑分布式光伏低电压穿越的配电网改进短路电流计算

Improved short-circuit current calculation for distribution network considering distributed photovoltaic with capability low voltage ride-through

分布式光伏电源规模化并网使传统的短路电流计算方法不再适用。文中通过对光伏电源的并网点电压和故障输出电流进行定量分析,改进了考虑低电压穿越策略的光伏电源故障等效模型,使其更适用于实际工程计算。在此基础上利用叠加原理将配电网短路故障等效电路分解为电源不突变网络和电源突变网络,提出了改进的含分布式光伏电源配电网短路电流计算方法。通过对算例的仿真计算和数据分析,验证了所提方法的准确性和时效性。

The large-scale integration of distributed photovoltaic power sources makes the traditional short-circuit current calculation method no longer applicable. In this paper,the quantitative analyses of both the grid-connected point voltage and fault output current of the photovoltaic power source are firstly applied to modify the photovoltaic power supply fault equivalent model considering the low voltage ride-through in order to make it more suitable for practical engineering calculations. Based on this,the short-circuit fault equivalent circuit of the distribution network is decomposed into a power supply non-mutation network and a power supply abrupt network by means of the superposition principle. And then,an improved calculation method for short-circuit current of distributed photovoltaic power distribution network is put forward. The proposed method is proved to be accurate and timely by the simulating calculation and data analysis.