Overvoltage Prevention and Curtailment Reduction using Adaptive Droop-based Supplementary Control in Smart Inverters
Recent developments in renewable energy sector has seen an unprecedented growth in residential photovoltaic (PV) installations. However, high PV penetration levels often leads to overvoltage problems in low voltage (LV) distribution feeders. Smart inverters can come in play to overcome these challenges by implementing different control strategies. One of the such PV inverter control approach is active power curtailment (APC) based overvoltage control method. The APC technique utilizes a constant droop-based approach which curtails power rigidly, based on the difference between the measured voltage and a critical voltage level. This can lead to significant energy curtailment in the LV distribution feeders. In this paper, different variations of the APC technique with linear, quadratic, and exponential droops have been analyzed from the point-of-view of energy curtailment for an LV distribution network in North America. Further, a combinatorial approach using various droop-based APC methods in conjunction with adaptive dynamic programming (ADP) as a supplementary control scheme has also been proposed. The proposed approach minimizes energy curtailment in the LV distribution network by adjusting the droop gains. Simulation results depict that ADP in conjunction with exponential droop reduces the energy curtailment to approximately 50% compared to using the standard linear droop.