Fault tolerant control of islanded AC microgrids under sensor and communication link faults using online recursive reduced-order estimation

Abstract

Cyber-Physical Systems (CPSs) have become an inseparable part of the new industrial era referred to as Industry 4.0 the quintessential example of which are smart grids. With a cyber communication level integrated with the physical components, besides considerable merits came along some reliability and security concerns. To address these issues, there ought to be a supervisory level monitoring and control system to identify any faults within the system and balance out their potential damaging impacts. In this paper, we consider fault tolerant control (FTC) problem in one of the building blocks of smart grids i.e. microgrids. The FTC method is based on online recursive reduced-order model estimation and Klaman Filter (KF) residual generation. Then, two-sided cumulative sum (CUSUM) sequential change detection algorithm is employed for sensor fault or communication link failure detection. Lastly, a fault-tolerant logic is constructed to switch between actual data and the internal model for the control system.