An H-infinity feedback control approach for three-phase voltage source converters

This research work introduces a new control method for feedback control of nonlinear power electronics systems with application example the problem of three-phase voltage source converters. The control method consists of a repetitive solution of an H-infinity control problem for the voltage source converter, that makes use of a locally linearized model of the converter and takes place at each iteration of the control algorithm. The converter´s model is locally linearized round its current operating point through the computation of the associated Jacobian matrices. Using the linearized model of the converter an H-infinity feedback control law is computed. The known robustness features of H-infinity control enable to compensate for the errors of the approximative linearization, as well as to eliminate the effects of external perturbations. The performance of the proposed control scheme is validated analytically and is confirmed through simulation experiments.