基于线路阻抗特性的SOP低电压穿越控制策略OA北大核心CSTPCD

Due to the fluctuation of output and uneven access location of distributed new energy,when it is connected to the distribution network on a large scale,the probability of failure will increase.How to ensure that the low voltage ride through(LVRT)of grid-connected power electronic equipment is the key technology to ensure the stable operation of the distribution network when the distribution network fails,and has become one of current research hotspots.Taking the soft open point(SOP)in the flexible interconnected distribution network as the object,combined with the impedance characteristics of the feeder line in the distribution network,this paper proposes a SOP LVRT control strategy based on characteristic impedance of feeder line.Firstly,it analyzes the influence of line impedance on the voltage of the converter connected to the common coupling point(PCC),and derives the mechanism of using the injected power of the converter to raise the voltage.Secondly,it proposes the equivalent impedance measurement method from PCC to fault point based on the local measurement data of feeder outlet side and converter and then construct the overall strategy of SOP LVRT based on impedance measurement method.Finally,the proposed control strategy is verified on the PSCAD simulation platform.The results show that the LVRT control strategy of SOP proposed in this paper can compensate active power and reactive power at the same time in different voltage drop ranges,which can significantly improve the voltage level of PCC point compared with reactive power compensation only.