Injection-Space Security Region for Sub/Super-Synchronous Oscillation in Wind Power Integrated Power Systems

Abstract

The complex interactions between converter-based wind turbine generators (WTGs) and power grid have brought new sub/super-synchronous oscillation (SSO) issues. The stability of such oscillation is closely related to system operating conditions. Thus it is necessary to identify SSO stability under various possible operating conditions. To achieve this, this paper first proposes the concept of security region (SR) for SSO, which is composed of all operating points in the injection space to ensure the stability of SSO modes. Then an operating condition dependent impedance model-based oscillation stability analysis method is developed to evaluate the SSO stability. Next, the predictor-corrector technique is adopted to build the SR boundary using the correlation among adjacent boundary points. The boundary is further approximated via hyperplane fitting according to its topological property. Finally, the proposed method is applied on a practical wind power system suffering SSO to construct the SR. Its effectiveness as well as advantages over traditional point-wise based method are demonstrated with random experiment and EMT simulation.