Analysis and control of bifurcations In power system with facts Controllers

Abstract

Electrical power system is a complex and nonlinear system that may show newlinevarious complicated events which have not been thoroughly examined until newlinenow. Power system exhibits rich nonlinear dynamic phenomena both newlineunder normal and emergency operating conditions. Sometimes variations newlineof any parameter may result in sudden change in the qualitative behaviour newlineof the power system. A linear analysis of such a system fails to explain newlinenonlinear characteristics like the presence of limit cycles, quasiperiodic newlinecycles, chaos etc. In this context it becomes essential to apply bifurcation newlinetheory which is a nonlinear analysis to understand the dynamics of the newlinepower system. newlineThe thesis presents the application of bifurcation technique to investigate newlineSubsynchronous Resonance (SSR) which is one of the power system newlineproblems observed in a series capacitor compensated long transmission newlinesystem connected to a turbogenerator. The problem of SSR occurs due newlineto the interaction between electrical modes and torsional modes at subsynchronous newlinefrequencies resulting in subsynchronous oscillations (SSO) newlinewhich increases the fatigue on the rotor shaft. newlineStatic Synchronous Series Compensator (SSSC), a series voltage source newlineconverter (VSC) based FACTS controller is very effective in enhancing newlinethe power transfer capability of the line and mitigating SSR in a hybrid newlinecompensated system. Static Synchronous Compensator (STATCOM), a newlineshunt VSC based FACTS controller improves dynamic voltage regulation newlineand damps low frequency oscillations. The operational flexibility of VSC newlinebased FACTS controllers can be enhanced by integrating an energy storage newlinesystem to the dc side of the converter to supply or absorb the active newlineand reactive powers. newline