Performance of OLTC-based control strategies for LV networks with photovoltaics

The adoption of on-load tap changer (OLTC)-fitted transformers in low voltage (LV) networks is increasingly being considered to mitigate voltage issues resulting from high penetrations of photovoltaic (PV) systems. However, depending on the corresponding voltage control strategy, tap operations can be significant, accelerating the ageing of the OLTC. This work assesses the performance of different OLTC control strategies: constant set-point, time-based and remote monitoring-based. A Monte Carlo-based time-series analysis is used considering different PV penetrations. A real UK residential LV network is analyzed using the number of tap operations and voltage compliance with the standard BS EN50160 as key performance metrics throughout a week. Results show that remote monitoring-based control can significantly enhance the network´s ability to host PV systems whilst limiting tap operations and voltage issues. The results are expected to help distribution network operators determine the most adequate control strategy for OLTC-fitted transformers in future LV networks.