Impact of Voltage Sensor Faults on Two-Level Hierarchical Control Required for Grid-Forming VSCs in Isolated Microgrids

With the advancement of technology, most physical systems have become cyber-physical due to their level of connectivity; therefore, are not only the effects produced by non-malicious faults being analyzed but also the faults caused by malicious attacks. This paper presents a dynamic analysis of the impact of voltage sensor faults on the two-level Hierarchical Control designed for managing the one-phase Distributed Energy Resources (DER) based on Grid-Forming Control (GFC). The hierarchical control strategy implemented and further analyzed under the influence of sensor faults states the capability of regulating the voltage in the isolated Microgrid (MG). In addition, the proposed control system can compensate for the voltage unbalance produced at the point of common coupling or critical bus below a reference quality value of 2%. The hierarchical control design seeks simplicity, low processing effort, and fast response. Finally, a dynamic analysis is carried out about the controller's capability to maintain the operating point in the event of different voltage sensor faults on the secondary control and the effect it imposes on the power quality generated in the MG. The Matlab/Simulink simulation platform has been used to test the performance of the proposed control strategy.