Adaptive Control Strategy of Energy Storage System Participating in Primary Frequency Regulation

Abstract

In order to solve the capacity shortage problem in power system frequency regulation caused by large-scale integration of renewable energy, the battery energy storage-assisted frequency regulation is introduced. In this paper, an adaptive control strategy for primary frequency regulation of the energy storage system (ESS) was proposed. The control strategy combined virtual droop control, virtual inertial control, and virtual negative inertial control. The virtual inertial control was used to reduce the frequency change rate, and the virtual droop control was used to reduce the steady-state frequency deviation. The virtual droop control and the virtual inertia control were adopted in the frequency deterioration stage to slow down the frequency drop. While in the frequency recovery stage, the virtual negative inertia control worked together with the virtual droop control to accelerate the frequency recovery. Besides, the coefficients of the control methods were related to the state of charge (SOC) of ESS to avoid over-charging and over-discharging of the battery. Finally, a simulation model was built in MATLAB/SIMULINK, and case studies were conducted to verify the proposed control strategy. Results showed that the proposed method could meet the demand for frequency regulation and was beneficial to the cycle life of ESS.

Comprehensive control method of energy storage system to participate in primary frequency regulation with adaptive state of charge recovery

“…The proposed integrated control strategy combines virtual droop control and virtual inertia control in the frequency deterioration phase, to reduce the frequency deviation and hinder the frequency from deterioration. In frequency recovery phase, the virtual droop control and virtual negative inertia control are combined to reduce the frequency deviation and accelerate the frequency recovery 17 . The output power of ESS in frequency regulation stage can be described as: …”

“…In frequency recovery phase, the virtual droop control and virtual negative inertia control are combined to reduce the frequency deviation and accelerate the frequency recovery. 17 The output power of ESS in frequency regulation stage can be described as:…”

Development of Energy Storage Systems for High Penetration of Renewable Energy Grids

“…Battery energy storage systems can be derived from many auxiliary services according to different control strategies, such as frequency regulation reserve, peak shaving and valley filling, smoothing of solar output power, load dispatch, islanding operation, reactive power compensation, and virtual inertia provision. In [9], by operating the battery energy storage system and implementing an adaptive primary frequency control strategy, the system frequency is adjusted by flexibly and rapidly controlling the charge and discharge capabilities of the battery energy storage system. An integrated control approach combines decentralized and cluster-based load control in McMahon et al [10], which uses a battery energy storage system to determine the activation and deactivation of flexible load clusters based on frequency measurements.…”

Coordinated Frequency Control of an Energy Storage System with a Generator for Frequency Regulation in a Power Plant

“…Therefore, ESS application for FR has a faster (quick) response, is less expensive, has a lower capacity in power plants, and offers a precise control capability over many conventional generators [7,8]. The flexibility and rapid control of the charge and discharge capabilities of ESSs to regulate the system frequency not only improves the FR performance, but also reduces the reserve of traditional units [9]. However, the use of only ESS for FR would require large storage capacity and energy, which is economically expensive [6,10].…”

“…Furthermore, ESS participation in primary frequency regulation uses both virtual droop control and virtual inertial control, which could increase the frequency nadir and effectively reduce the rate of change of frequency (RoCoF) [15]. Reference [9] proposed a control strategy in which virtual inertial and virtual negative inertia control methods were implemented to prevent frequency deterioration and accelerate frequency recovery, respectively, for ESS participation in primary frequency control (PFC). Another previous study [16] proposed droop control for battery energy storage system (BESS) participation in system-grid FR by adjusting the BESS output according to the fixed sagging coefficient.…”