Open Access

ARTICLE

Coordinated Control Strategy for Active Frequency Support in PV-Storage Integrated Systems

Junxian Ma¹, Haonan Zhao^2,*, Zhibing Hu³, Yaru Shen³, Fan Ding³, Shouqi Jiang²
1 State Grid Ningxia Electric Power Co., Ltd., Yinchuan, 750000, China
2 Northeast Electric Power University, School of Electrical Engineering, Jilin, 132012, China
3 Economic and Technological Research Institute, State Grid Ningxia Electric Power Co., Ltd., Yinchuan, 750000, China
* Corresponding Author: Haonan Zhao. Email:

Energy Engineering https://doi.org/10.32604/ee.2025.070530

Received 18 July 2025; Accepted 26 August 2025; Published online 19 September 2025

Abstract

Energy storage-equipped photovoltaic (PV-storage) systems can meet frequency regulation requirements under various operating conditions, and their coordinated support for grid frequency has become a future trend. To address frequency stability issues caused by low inertia and weak damping, this paper proposes a multi-timescale frequency regulation coordinated control strategy for PV-storage integrated systems. First, a self-synchronizing control strategy for grid-connected inverters is designed based on DC voltage dynamics, enabling active inertia support while transmitting frequency variation information. Next, an energy storage inertia support control strategy is developed to enhance the frequency nadir, and an active frequency support control strategy for PV system considering a frequency regulation deadband is proposed, where the deadband value is determined based on the power regulation margin of synchronous generators, allowing the PV-storage system to adaptively switch between inertia support and primary frequency regulation under different disturbance conditions. This approach ensures system frequency stability while fully leveraging the regulation capabilities of heterogeneous resources. Finally, the real-time digital simulation results of the PV-storage integrated system demonstrate that, compared to existing control methods, the proposed strategy effectively reduces the rate of change of frequency and improves the frequency nadir under various disturbance scenarios, verifying its effectiveness.

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Keywords

PV-storage integrated systems; inertia self-synchronization control; primary frequency regulation; frequency stability

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