Power quality is one of the most important issues that distribution Utilities face. Voltage sag is one of the most common types of short-term voltage variations, that have many undesirable effects on the network. Due to the nature of the temporal occurrence of this phenomenon, it must be quickly detected and controlled at the lowest possible time. This issue requires taking a decentralized approach. Network partitioning is one of the best so- lutions. In this study, the voltage sag problem and network partitioning are investigated. In this regard, the concept of oscillations radius is defined. According to the SteadyState voltage measurements and the network impedance matrix, the oscillations of each bus are determined based on their oscillation radius and according to the oscillation area of each bus, the network can be partitioned. As a result, the voltage sag profile is improved due to the optimal location of installation of DVR sources in each area. In addition, a method has been proposed to detect the characteristics of voltage sag, such as the start, end, and period of this disturbance. the accuracy of the proposed method on the IEEE 33-bus distribution system is investigated and carried out in MATLAB/ Simulink.
