Voltage optimization control for small hydropower cluster connected to distribution power network in different spatiotemporal scenarios

China is vigorously developing distributed small hydropower in rural areas. However, the large-scale integration of small hydropower into distribution networks causes voltage fluctuations and over-limits due to seasonal variations in power output. To ensure the safe and stable operation of the distribution network, a voltage optimization strategy based on the adaptive shrinkage factor particle swarm optimization (ASCF-PSO) algorithm is proposed. The strategy involves dividing small hydropower into clusters and coordinating the optimization of reactive power compensation devices and cluster output, with the goal of minimizing node voltage deviation and network loss under different spatiotemporal scenarios. Simulations conducted on a 33-node system using actual output data from multiple small hydropower stations in the Meijiang River Basin. It shows that ASCF-PSO can keep all node voltages within the normal range and improve the rationality of power distribution. This study provides an effective solution for the safe and stable operation of distribution networks with high penetration of small hydropower.