Enhancing Resilience of Microgrids With Electric Springs

Extreme natural events have caused severe power system blackouts in recent years. It is important for power systems to survive after such events and recover the power supply, especially for critical loads (CLs), as soon as possible. In this paper, a control strategy is proposed for electric springs (ESs) to enhance resilience of microgrids with fluctuating renewable resources. First, the feasible operating region of the ES and the power-voltage curve of the bus connected with the ES are derived analytically. Second, according to the derived feasible operating region, a novel control strategy of ES is proposed to regulate the frequency and voltage of microgrids with and without a communication system. The voltages on CLs are considered as a critical constraint for enhancing resilience during extreme natural events. Finally, the method to enhance resilience of microgrids with ES under both the frequency support mode and the voltage support mode are studied. Case studies demonstrate that ESs can enhance the resilience of microgrids with the proposed strategy with and without a communication system after extreme natural events.