NIDI: A robust system for identifying distortion and imbalance sources in microgrids

• Portable, low-cost system for microgrid power quality analysis. • Accurate identification of distortion and imbalance sources. • DSI/ISI algorithms simplify power quality disturbance diagnosis. • Operates under distorted and unbalanced voltage conditions. Electric power quality is becoming increasingly important over time due to the growing use of electronic devices across various sectors of society, including industry and households. Numerous disturbances can occur in the power grid due to both external and internal causes, such as switching devices on and off. Among these disturbances, distortion and imbalance are particularly problematic because they are pseudo-permanent disturbances, making them very dangerous for electrical equipment. Moreover, identifying the sources of distortion and/or imbalance is quite challenging because they are instantaneously scattered throughout the grid. This paper presents a complete experimental prototype designed to identify both distortion and imbalance sources in a microgrid, which would allow for their compensation at the node of origin. The proposed system comprises all necessary hardware and software, and is based on low-cost, free-software and open hardware. Simulation and experimental results are presented, each demonstrating the system’s performance.