Abstract: In order to realize the coordinated reactive power optimization operation of distribution network and main network with high permeability photovoltaic, a novel optimization method of main distribution network coordination is proposed to address the volatility of photovoltaic power output. Firstly, the probabilistic models of load and PV output are established, and fast statistics of nodal voltages are realized using a probabilistic load flow algorithm combining the semi-invariant method and the Gram-Charlier series. Secondly, decompose the main and distribution networks and consider their mutual support effect, improve the particle swarm algorithm, and embed the probabilistic load flow calculation into the algorithm for voltage optimization. Finally, a main distribution network example is constructed for simulation. The results demonstrate that, the proposed coordinated optimization method considering photovoltaic fluctuation can more effectively achieve optimal operation of main distribution networks with high-penetration photovoltaic.

    Key words: main distribution network coordination; reactive power optimization; probabilistic load flow; semi-invariant method;Gram-Charlier series; particle swarm optimization