Structural Analysis of Voltage Stability in Power Systems Integrating Wind Power

This paper presents a structural voltage stability analysis of a power system integrating induction generator wind turbines. The approach is based on restructuring the system load flow matrix (J_LF) with respect to bus types instead of the usual active-reactive power equations arrangement. The row sub-matrices of the modified J_LF are used to generate sub-matrices candidates representing associations of bus types. Singular value decomposition (SVD) of the generated sub-matrices is used as a rank deficiency indicator. The approach is tested on a nine-bus system. The proximity to voltage collapse is monitored by tracking the smallest SVD and points of limit induced bifurcations are tracked. The interactions between the system buses are structurally analyzed for wind power increase and loading tests. Two-bus bifurcations are shown to be a precursor to system voltage collapse. The analysis is helpful for problem diagnosis and remediation planning in power systems.