Study on Reactive Power‐Voltage Coupling Sensitivity for Large‐Scale Renewable Energy Clusters

ABSTRACT

With the rapid growth of renewable energy generation, wind and photovoltaic power plants are increasingly integrated into power grids in clusters, with each plant equipped with an automatic voltage control (AVC) substation for voltage regulation. However, parallel aggregation and hierarchical step‐up connections of multiple substations introduce strong inter‐station coupling and operating uncertainty into regional voltage control, rendering traditional reactive power‐voltage sensitivity (Δ Q /Δ U ) methods developed for individual stations inadequate. Existing studies neither systematically address typical cluster topologies nor enable conventional Jacobian‐matrix‐based methods to explicitly account for active power fluctuations. This paper proposes a practical framework for calculating, simplifying, and correcting the reactive power‐voltage sensitivity of renewable energy clusters. The framework accommodates different cluster topologies, accounts for active power fluctuations and inter‐station coupling, and enables sensitivity updates following topology switching or temporary substation non‐response. First, reactive power‐voltage sensitivity models incorporating active‐power fluctuations are derived for typical structures. Subsequently, based on the dominant factors analysis, a simplified inter‐station decoupling method and a generalised sensitivity calculation algorithm applicable to hybrid cluster topologies are developed. Furthermore, a sensitivity correction strategy is proposed to account for sensitivity‐matrix variations caused by main‐grid topology changes or temporary substation non‐response. Case studies demonstrate that the proposed method can improve the ability of individual substations to follow AVC dispatch commands while enhancing regional voltage regulation performance.