Title :
Nonlinear stability analysis for ac/dc voltage source converters driven by PI current-mode controllers
Author :
Krommydas, Konstantinos F. ; Alexandridis, Antonio T.
Author_Institution :
Electr. & Comput. Eng. Dept., Univ. of Patras, Rion, Greece
Abstract :
Voltage source converters operating under current-mode controllers perform a standard and extremely common scheme in many industrial applications. In this paper, the open problem of designing and analyzing such nonlinear systems is addressed. To this end, a novel passivity-based stability analysis is developed that takes into account the accurate entire nonlinear model of the system with the proposed current-mode proportional-integral (PI) controllers selected to be independent from the system parameters. In particular, a new sequential method is developed that provides the suitable Lyapunov function for the entire closed-loop system. Using this Lyapunov storage function input-to-state stability is proven; moreover, exploiting some new advanced nonlinear methods, it is shown that convergence of the closed-loop system states to the desired unique equilibrium is guaranteed. Simulation results verify the theoretical analysis providing a very good transient response and convergence to the desired steady state.
Keywords :
AC-DC power convertors; Lyapunov methods; PI control; closed loop systems; electric current control; nonlinear control systems; stability; Lyapunov storage function; PI current-mode controllers; ac/dc voltage source converters; closed-loop system; current-mode proportional-integral controllers; nonlinear stability analysis; nonlinear systems; passivity-based stability analysis; sequential method; Closed loop systems; Convergence; Power conversion; Reactive power; Stability analysis; Steady-state;
Conference_Titel :
Control Conference (ECC), 2014 European
Conference_Location :
Strasbourg
Print_ISBN :
978-3-9524269-1-3
DOI :
10.1109/ECC.2014.6862452