On the cascading effects of residential-scale PV disconnection due to voltage rise

Photovoltaic penetration in LV networks can produce voltage rise above the limits, resulting in the automatic disconnection of panels. This voltage-driven disconnection of particularly single-phase PV panels combined with the unbalance nature of LV networks might produce a further voltage rise in one of the other phases. This can result in a new PV disconnection. This paper analyses to which extent the risk of PV cascading exists in LV networks. A 5-minute time-series power flow analysis is adopted using a real LV network (7 feeders and 346 customers) in the North West of England. The results indicate that the risk of cascading does exist. However, the proportion of cascading disconnections is likely to be small (although increases with PV penetration). Moreover, cascading disconnections happen mostly in the period after the first automatic disconnection(s). Consequently, the actual cascading nature is very limited.