Method of reactive power compensation for medium voltage feeder voltage fluctuations considering random output superposition of source load timing characteristics

In order to address the impact of timing and volatility on the dynamic characteristics of medium voltage (MV) feeders following the grid connection of numerous distributed power sources, as well as the phenomenon of voltage overruns caused by the superposition of random outputs, this paper proposes a reactive power compensation method for MV feeder voltage fluctuation, considering the superposition of random outputs based on the sequential characteristics of sources and loads. The method combines the time-sequence processing characteristics of “source” and “load,” analyzes the effects of their superposition, and then uses the reactive power compensation devices for the MV feeder reactive power compensation to regulate the current voltage of the MV feeder. The optimization model is constructed based on the reactive power compensation device, the transient voltage stability margin and threshold difference are maximized, the loss is minimized, and the reactive power cost is minimized as the optimization objective function, as well as the capacity and number of reactive power devices and other constraints. The optimization model is solved by using the improved particle swarm algorithm to obtain the best optimization results of voltage fluctuation suppression. The results show that the method can reliably analyze the actual processing superposition state of the source–load time-sequence characteristics, the fluctuation range of the voltage after compensation optimization is located between 0.95 and 1.05 p.u., and the fluctuation amplitude is relatively smooth. The results of the voltage stability margins are above 0.10, which can ensure the voltage stability and avoid the occurrence of the voltage overrun.