Hopf bifurcations induced by SVC Controllers: A didactic example

This paper illustrates the effects of a static var compensator (SVC) device on the stability of a simple “single-machine dynamic-load” system. Firstly, the stability of the test system without SVC is investigated. The analysis is based on bifurcation diagrams, small signal stability analysis and time domain simulations. Without the SVC device, the system presents a saddle-node bifurcation. Then, static and dynamic analyses are repeated for the system with a SVC device located at the load bus. The SVC is able to improve system loadability but leads to a Hopf bifurcation. Finally, a multi-parameter bifurcation analysis is presented to study the effect of system parameters on the Hopf bifurcation.