A Novel Unknown Input Observer-based Measurement Fault Detection and Isolation scheme for Micro-Grid Systems

Correct measurement of different signals used in the micro-grids control center (MGCC) is crucial for their operation, control, and stability. This is especially true for micro-grids operating in island mode. To keep their operation efficient and safe, faulty sensors should be instantly isolated. To this end, novel sensor fault detection and isolation schemes are proposed in this paper that are built based on unknown input observer method (UIO). In this method, load fluctuations and output power variations of renewable energy sources are modeled as unknown inputs. Theoretical analysis and simulation scenarios are carried out on a micro-grid system which consists of different types of energy generation sources and energy storage systems to prove the robustness of the proposed sensor fault detection and isolation schemes. The simulation results also show the ability of the proposed schemes in detecting and isolating faulty sensors in real time, including cases of simultaneous faults.