This paper presents a method for harmoniously coordinating roles between generators and faster-acting energy storage systems (ESSs), e.g., batteries, to improve their frequency response and regulation services to the grid, particularly at the high wind penetration. This paper theoretically demonstrates that the proposed droop with the state of charge (SOC) feedback (DaSOF) provides a unified frequency control framework for distributed and energy-constrained ESS, seamlessly fitting the conventional primary and secondary frequency control practice. The ESS autonomously takes charge of high-frequency components of a frequency deviation and thus complements the frequency controls of the incumbent generators. By securing the SOC of the ESS at the desired level, the method provides the capability to provide other ancillary services from the energy-constrained ESS. These coordinated roles are represented and validated through time- A nd frequency-domain analyses. Rigorous case studies using DIgSILENT/PowerFactory demonstrate the efficacy of the proposed method to support the high level of variable renewable energy, which should help in improving the value of operating the ESS and scale up renewable energy.
Bibliographical noteFunding Information:
Manuscript received August 1, 2017; revised November 24, 2017 and March 23, 2018; accepted May 6, 2018. Date of publication May 15, 2018; date of current version October 18, 2018. This work was supported in part under the framework of international cooperation program managed by the National Research Foundation of Korea under Grant 2017K1A4A3013579. This research was supported by Korea Electric Power Corporation under Grant R17XA05-4.
© 2018 IEEE.
All Science Journal Classification (ASJC) codes
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering