Optimized Hierarchical Control For An Ac Microgrid Under Attack

Context: An inverter-based microgrid working in islanded mode can suffer cyber-attacks, these can be done against either the local controller or the communication links among the inverters. Secondary control is able to reject those attacks, however, a tertiary control action is necessary in order to stabilize the power flow among the microgrid.Method: Confidence factor technique allows to reject attacks in a microgrid acting directly over the secondary control, however, this technique omits other factor related to the power available. In this case, secondary control was complemented with a tertiary control that includes optimization criteria.Results: An inverter-based microgrid is simulated in Matlab for different scenarios and under cyber-attack, this allows checking the correct response of the controller under attacks and the effective power-sharing among inverters.Conclusions: The tertiary control allows stabilizing the active power of the system after the rejection of a cyber-attack by the secondary control. Each inverter supplies active power according to its maximum power rating without affecting the stability of the whole system.