Research on voltage coupling mechanism of MV-LV distribution network under high-proportion distributed PV penetration

With the rapid growth of distributed photovoltaic(PV) installed capacity, the access of large-scale distributed PV has brought the distribution network problems such as power flow return and voltage exceeding. At present, there have been abundant researches on the impact of high proportion of PV on the voltage of distribution network, but most of them only consider the situation of a single voltage level distribution network, instead of the coupling effect between different voltage levels. Therefore, this paper took the 10kV/380V distribution network as the research object, firstly analyzed the mechanism of voltage interaction between medium and low voltage distribution networks, then established the voltage evaluation indexes of medium voltage-low voltage(MV-LV) distribution networks, finally used an actual distribution network in Chengde as case to verify the coupling mechanism through the MATPOWER platform, as well as evaluated its voltage characteristics. The work done in this paper makes the evaluation of the voltage characteristics of the distribution network more realistic and has certain engineering significance.