Frequency coordinated control strategy based on sliding mode method for a microgrid with hybrid energy storage system

Abstract

Abstract Frequency stability is important for microgrid with renewable energy. However, the deterioration of frequency and the increased energy storage equipment are caused by source‐load uncertainty. Therefore, a frequency coordinated control strategy based on sliding mode method for a microgrid with hybrid energy storage system (HESS) is proposed. First of all, the detailed frequency regulation is designed, which divides deviation of frequency and area control error into different components as power reference value of different power supply. Secondly, the power threshold of HESS, which is consisted of ultra‐capacitor and battery, is set by designed fuzzy controller to reduce reserve power of HESS and avoid unreasonable power output. Thirdly, a load frequency control model with HESS is built and a sliding mode control is designed by using the detailed frequency regulation. Finally, the effectiveness of the proposed frequency coordinated control strategy is verified through comparison of different cases.

Keywords

• Frequency control
• Control of electric power systems
• Distributed power generation
• Power system control
• Control system analysis and synthesis methods
• Multivariable control systems