Small-Signal Stability Assessment of Multi-infeed Converter Power System with SVGs

The modern power gird is being transformed into a multiple converter system (MCS) driven by the increasing integration of converter-based resources (CBRs) such as wind and solar. In such an MCS, the dynamic interaction between converter controls and the power network may cause the small-signal stability issues. While static var generators (SVGs) are integrated into the MCS for providing voltage support, they may affect the small-signal stability. To understand the impact of SVGs, this paper investigates the small-signal stability of the MCS with SVGs. By constructing an equivalent model, the theoretical analysis finds two key factors affecting the small-signal stability when SVGs are connected to the MCS: 1) the topology and parameters of the power network interconnecting SVGs and CBRs; 2) the dynamic interaction between the SVGs and CBRs. Based on the results, a computationally efficient method is proposed to assess the small-signal stability of the MCS with SVGs. The analysis results and the proposed method are validated through eigenvalue analysis, and electromagnetic transient simulation.