Voltage Coordination Control of Photovoltaic Storage Clusters in Active Distribution Networks

The distribution network in northwest China has the characteristics of long lines and obvious load peaks and valleys. With the continuous increase in the number of distributed photovoltaic (PV) connections, it is prone to the problem of high PV output during the day and lower line voltage when the load becomes heavier at night. In order to enhance the regulation capability of the distribution network when the voltage exceeds the limit in this situation, this paper proposes a voltage control strategy based on the coordination regulation of PV storage clusters. Firstly, a comprehensive cost control objective for intra cluster regulation was proposed, taking into account the charging and discharging costs, PV's abandonment costs, and line network losses during the energy storage (ES) life cycle. Based on cluster network separation and second-order cone relaxation (SOCR), an optimal power flow calculation model was established within the cluster to achieve optimized control. Secondly, based on the alternating direction multiplier method (ADMM), cluster boundary data exchange rules and control objectives with boundary variable constraints are established. Through iterative data exchange, optimal control between clusters is achieved, thereby achieving global optimal regulation of PV and ES. Finally, the effectiveness of the proposed method were verified through simulation using the IEEE33 node system.