Microinverter curtailment strategy for increasing photovoltaic penetration in low-voltage networks

Transition toward smart distribution networks with high penetration of photovoltaics (PVs) will involve incidental generation curtailment as an alternative to grid reinforcements. Microinverters are taking over popularity of string inverters in residential and some commercial areas mainly due to increased energy harvest. This paper demonstrates how microinverters with a modified overvoltage protection scheme could provide a reliable curtailment solution and accommodate additional PV capacity. Two wide-area curtailment schemes were proposed for a typical Dutch residential feeder with densely clustered PV. First, a single worst-case scenario was used to demonstrate the capabilities of the proposed curtailment schemes: the distribution network operators can optimize between various priorities such as total feeder output, economic equality between connected parties, voltage levels, voltage unbalance, and curtailment execution time. Second, a yearly comparison was made against conventional overvoltage protection and the results show 62%–100% reduction in overvoltage losses.