Hierarchical Control Strategy for Multiple Reactive Power Resources in Low-Voltage Distribution Networks Considering Regulation Costs

In low-voltage photovoltaic distribution networks, the large-scale integration of distributed PV systems has led to frequent voltage fluctuations. Traditional reactive power control strategies exhibit significant shortcomings in terms of flexibility, voltage regulation, and economic efficiency. This paper focuses on low-voltage PV distribution areas and proposes a hierarchical optimization control strategy for reactive power resources to mitigate voltage fluctuations. First, a tiered control rule is designed based on the degree of voltage fluctuation. Then, cost functions are established for three types of reactive power devices. On this basis, a multi-objective function is constructed for control decision-making. Finally, simulation verification is conducted based on a real distribution feeder model in Hainan under typical daily solar irradiance and load scenarios. The results show that the proposed strategy significantly reduces both the frequency of reactive power adjustments and the total regulation cost while effectively suppressing voltage fluctuations, demonstrating strong engineering adaptability and application potential.