Islanded AC Microgrid Stability and Feasibility Analysis on V-P Control with Estimation at Constant Frequency

This paper addresses the issue of transient stability and control in switching mode islanded AC microgrid. The innovations are topology modeling, varying state analysis and optimal estimation. A voltage-active power controller with state estimator under constant frequency is proposed to regulate grid current and inverter power. Transient small signal stability and control loop feasibility are studied. After finding stable range, simulation results show that system responds in 0.1 second, with -58dB distortion, steady state error smaller than 5%. This controller with estimator is preferable for islanded AC microgrid due to its simplicity and fast-tracking performance.