Advanced centralized protection system for AC microgrids using TW-DWT techniques

• Proposing a novel centralized protection scheme for AC Microgrid systems. • Applying TW and DWT techniques to enhance fault detection and classification. • Designing a central protection unit for comprehensive fault management. • Implementing LoRaWAN for efficient and reliable data communication. • Validating the method's versatility across different system configurations. Microgrid protection has made significant strides in recent years, yet distribution system operators face substantial challenges. The advent of microgrid operation has revealed the limitations of existing protection devices, particularly in recognizing, classifying, and locating various types of faults when in islanded mode. The dynamic nature of microgrids complicates fault management. This paper presents a methodology for a central protection unit that includes fault detection and classification, fault location estimation, and faulty line isolation. The proposed method utilizes discrete wavelet transform and traveling wave techniques with a central protection unit. The central protection unit depends on the LoRaWAN communication technique to transmit data between the central protection unit and the system. A test system developed entirely in MATLAB/Simulink is used to demonstrate the accuracy of each feature of the protection algorithm applied in microgrids. The proposed method is tested and simulated on two systems: one is a ring system, and the other is an IEEE 13 bus system. Different types of faults at various locations have been tested and simulated. The results show the method’s effectiveness, indicating its potential to enhance the current protection system and pave the way for implementing a modern microgrid station protection system. The fault clearance time is within 11.5 ms for the IEEE system and 7 ms for the ring system.