Optimal reactive power and voltage control in regional power grids using temporal segmentation of wind and PV generation

• Proposed a temporal segmentation strategy for renewable outputs to leverage wind-PV complementarity, enhancing utilization and optimizing reactive power allocation for grid voltage quality. • Developed a segmentation-based reactive pricing model and multi-objective reactive-voltage optimizer for regional grids with wind-solar-thermal-storage integration. • Employed an enhanced golden jackal optimizer (EGJO) to solve the nonlinear optimization problem, boosting global-local search efficiency. To address the issues of excessive active power losses, significant voltage fluctuations, and persistently high reactive power costs as well as environmental protection costs in regional power grids caused by high-proportion renewable energy integration, a reactive power-voltage optimization method incorporating a wind-solar time-series segmentation strategy is proposed. Firstly, based on the intraday fluctuation characteristics of wind and photovoltaic (PV) generation outputs, the Top-Down algorithm is employed to realize dynamic time-series segmentation of wind and solar power outputs. Secondly, for each time interval, a reactive power-voltage optimization model involving multi-energy sources (including wind, solar, thermal power, and energy storage) is constructed, with the objective of minimizing the sum of standardized system total active power loss, total voltage deviation, reactive power sources’ costs, and environmental protection costs of thermal power units. An improved golden jackal optimization (IGJO) algorithm is introduced for solving the model. Finally, simulation validation is conducted based on the modified IEEE 30-bus system. The results indicate that the proposed method achieves precise optimization in different time periods through time-series segmentation, reducing the system’s total active power loss by 40.7%, improving the total voltage deviation by 2.6%, increasing the renewable energy utilization rate by 6.7%, and decreasing environmental protection costs by 6.2%. These findings verify its coordinated optimization effect in terms of economy and environmental performance, providing a technical reference for the refined regulation of reactive power and voltage in regional power grids with high-proportion renewable energy. However, its engineering adaptability in large-scale actual power grids requires further verification.