Improving fairness in photovoltaic curtailment via feedback-driven daily topology reconfiguration in power distribution networks

In PV-rich power distribution systems, over-voltage issues are often mitigated by curtailing excess generation from PV plants, alongside reactive power control. However, PV plants located at the feeders’ end are often curtailed more frequently, raising fairness concerns. Current fairness-aware schemes address this issue by incorporating fairness objectives into the cost function. However, this often results in an overall increase in total curtailment, making the solution sub-optimal. This paper proposes a solution through daily topology reconfiguration, ensuring that different PV plants face varying grid conditions each day, leading to different curtailment levels and hence enhancing fairness. We illustrate that implementing this approach enhances overall fairness without significantly increasing overall curtailments. The optimization problem involves two stages: day-ahead and real-time. The day-ahead stage optimizes the network topology using day-ahead forecasts of PV generation and demand, minimizing net curtailment and accounting for fairness based on previous days’ curtailments. The real-time stage controls the active and reactive power for the PV plants with refined short-term forecasts. We use linearized DistFlow equations and first-order Taylor approximation of the AC power flow equations for modeling the grid constraints in day-ahead and real-time stages. The proposed scheme is numerically validated on standard balanced and unbalanced distribution systems. The results are compared using the Jain Fairness Index, considering fairness and reconfiguration scenarios.