Improving LV networks hosting capacity via the use of PV and BESS inverter controls – a Monte-Carlo analysis

Due to the rapid increase in residential PV capacity, it gets more and more difficult for an LV grid to absorb power at peak hours due to overvoltage issues, causing concerns to DSOs and prosumers who are temporarily unable to inject power into the grid. In collaboration with Belgian DSOs and via the use of metered consumption and injection data, dedicated Monte-Carlo analyses were performed to investigate mitigation measures. The focus in this paper is the use of P-Q control strategies of residential PV inverters, which includes:constant tan(φ), cos(φ) = f(P), Q(U) and P(U). Even though only some countries already have a clearly defined regulatory framework for such use of residential PV inverters, it is worthy to analyse the potential benefits of this approach. A parametrized LV feeder was modelled in an electrical modelling tool and Monte-Carlo simulations were performed, with variations of different input parameters and randomly assigned consumer/prosumer load and injection profiles based on an existing set of households’ data, as well as different strategies of P-Q inverter control. The risk for overvoltage occurrences was assessed (mostly focusing on periods with maximum irradiance). Besides the impact of different parameters such as the feeder’s length or the number of houses with PV on the feeder, a specific attention was paid to the beneficial impact of using the different P-Q control strategies. Dedicated KPI’s regarding the impact on prosumer households were analysed and the different P-Q control strategies were discussed.