Frequency Control Strategy for High-Penetration Renewable Power Systems with Voltage-Sensitive Flexible Load Clusters

Abstract

The high penetration of renewable energy has posed significant challenges to frequency regulation, primarily due to the scarcity of traditional regulation resources in these regions. To address this, a novel secondary frequency regulation control method utilizing voltage-sensitive flexible load (VSFL) clusters is proposed. The strategy leverages the voltage-active power coupling characteristics of composite loads. By regulating the load voltage, composite loads under 110/10 kV substations are transformed into controllable loads, which are then aggregated to collaborate with Automatic Generation Control (AGC) units in SFR. To tackle the inherent uncertainty in load regulation capacity, a load control signal correction strategy based on Tube-based Model Predictive Control (T-MPC) is designed. This strategy effectively compensates for calculation errors in control objectives caused by load uncertainty, achieving optimal control with minimal cost. Simulation results demonstrate that the proposed scheme enables the large-scale mining and flexible utilization of load-side regulation resources. Furthermore, the T-MPC approach exhibits superior robustness and frequency regulation performance compared to traditional MPC methods.