Voltage optimization strategy for active distribution network based on distributed photovoltaic cluster control

High penetration of distributed photovoltaic causes voltage violation problem in active distribution network. In order to solve this problem, a voltage optimization strategy based on distributed photovoltaic cluster control is proposed for the active distribution network. Firstly, with economic operation as the objective,shiftable load dispatch, the tap positions of on-load tap-changing transformers, and the output of capacitor banks are determined in the day-ahead stage. Subsequently, the approximate voltage sensitivity is calculated based on the day-ahead scheduling results, and clusters are partitioned using the K-means algorithm according to a comprehensive clustering index. Finally, in the intra-day stage, the cluster self-regulation is carried out based on the cluster adjustment characteristics, aiming at minimizing the internal network losses or the node voltage deviations. The inter-cluster coordination optimization is then performed based on the alternating direction multiplier method. Deploy this strategy on the IEEE 33-node system, and conduct a comparative analysis of voltage regulation effectiveness under various weather conditions and different scheduling strategies. The results show that after the day-ahead centralized optimization, the node voltages are within the limit range. After the intra-day rolling optimization, the voltage deviation is further reduced, and the deviation does not exceed 3% on sunny days. The case study results verify that the proposed optimization strategy guarantees voltage quality and meanwhile improves operational efficiency of distribution network.