Input - output linearization control for a three - phase AC/DC/AC voltage source converter for bidirectional power flow

Abstract

In this paper the bidirectional power capability of a three-phase AC/DC/AC voltage-source converter is studied; based on the input-output linearization control theory, which is applied to the inner current loops that are connected in cascade with the outer loops. Both loops (inner and outer) allow a suitable control of the power flow. The controlled system is linearized and decoupled; based on the dq mathematical model the current control and the state feedback law is obtained. The control strategy allows the AC/DC/AC converter to increase its flexibility to process power by decoupling the active and reactive components in the full operating range. An integral control to robust the system and eliminate the tracking error is added. The proportional-integral controller of the inner loops offers global tracking of the system in real practices. By simulation and experimental results the proposed control approach is validated.