A Node Backtracking-Based Sub-Supersynchronous Oscillation Observation Method in Radial Networks

The large-scale integration of renewable energy generation is accelerating the power electronics transformation of power grids, while simultaneously leading to a significant increase in Sub-Supersynchronous Oscillation (SSO) events and power quality issues. To address these challenges, this paper proposes a novel modal decomposition-based node backtracking method for oscillation observation and location method in an entire radial networks. This method utilizes wide-band synchronized phasor measurement units (WPMUs) installed at critical nodes in the grid to acquire limited measurement data, enabling system-wide oscillation monitoring with minimal WPMU deployment. Initially, the relationship between oscillation current/voltage distribution patterns and WPMU configuration parameters is investigated under single oscillation source scenarios. The WPMU configuration cost is analyzed from a measurement channel perspective, exploring the correlation between voltage and current measurement channels. By leveraging network topology and combining oscillation voltage measurements at the critical node with branch oscillation current measurements, the method calculates estimation value of oscillation voltage for each node using iterative algorithm. These virtual measurements are compared with actual oscillation voltage measurements at the end node after each iteration. Through this node backtracking approach, the oscillation situation of the entire network is progressively measured. The effectiveness and accuracy of the proposed method are validated using the IEEE 33-bus distribution system as a case study. Comparative results demonstrate that this node backtracking based oscillation source localization method efficiently addresses SSO observation and location in an entire radial networks, while offering significant advantages in WPMU deployment costs. The proposed method is applicable to networks with radial topology, including photovoltaic (PV) plants, wind farms, and distribution systems, demonstrating broad applicability.