Photovoltaic Hosting Capacity Margin due to State Estimation Error

The widespread adoption of distributed Photovoltaics (PV) has sparked a need for more accurate situational awareness in low-voltage distribution networks. This article presents various metering configurations which are compared in balanced and unbalanced conditions and different state estimation frequencies. Smart meter-derived pseudo-measurement configurations are compared to real-time metering in order to address the practical balance between the number of meters and state estimation accuracy. Moreover, a PV safety margin is presented as a margin of injected PV power that is equivalent to a voltage rise, which is derived from the estimation error. The results show a significant need to reduce the PV injected power to hold the estimated voltage below the actual voltage safely. For a network with just a few real-time measurements, the PV margin can reach tens of percentage points relative to the PV peak power. Additional real-time meters reduce the PV margin, however, the estimation accuracy saturates as more meters are added. Alternatively, the inaccuracy, and thus the PV margin, can be countered by the increased granularity of measured data.