AC-DC power conversion; D-Q synchronous reference frame; Input-output linearization Ac-dc power conversion; Control schemes; Current controller; Current loop; DC-bus voltages; External control; Harmonic contents; High power factor; Input output linearization; Internal dynamics; Multilevel rectifier; Nonlinear state; Parametric variation; PI Controller; Steady state errors; Synchronous reference frame; Voltage controllers; Zero dynamics; Attitude control; Behavioral research; Computer simulation; Controllers; DC power transmission; Electric current control; Electric power factor; Feedback; Linearization; Nonlinear feedback; Power electronics; State feedback; Electric rectifiers