Control scheme of a Three-Phase Three-Level NPC qZ-Source inverter with LCL filter for RES applications

Abstract

This paper presents the design for the control scheme of a three-level three-phase neutral-point-clamped quasi-Z-Source inverter which employs an LCL filter for the connection to the grid. A state-feedback based control is developed so as to attain a fully decoupled control of the active and reactive power exchanged with the grid. In addition, a PI regulator is tailored in order to control the dc-link voltage of the inverter. The complete control strategy, along with the inherent capabilities of the quasi- Z-Source inverters, signifies that this kind of power converters is suitable for renewable energy source applications.