Some Design and Simulation of Sliding Mode Variable Structure Control for Hopf Bifurcation in Power Systems

摘要

In power systems, the Hopf bifurcation (HB) can occur before the saddle-node bifurcation (SNB) and be-comes one of main reasons of voltage instability and collapse, so the bifurcation control for HB has impor-tant significance in improving power system voltage stability. In this paper, the numerical bifurcation analy-sis software MATCONT was used to study bifurcation behavior of a single-machine dynamic-load (SMDL) system with SVC, and the simulation analysis results show that a unstable Hopf bifurcation (UHB) point oc-curring before SNB point and engendering potential harm to voltage stability. To delay or eliminate the UHB phenomenon and enhance voltage stability of the SMDL system with SVC, we designed a sliding mode variable structure controller. The switching function and control variables of the controller are clearly de-scribed and the derivations are directly provided in detail in this paper. The MATLAB simulation results prove that the designed controller can eliminate the UHB point effectively and ensure safe and stable opera-tion of the system.