Multilevel inverter operated by voltage orientation control

This paper presents an innovative control scheme for the multilevel inverter that is connected to the power grid as a Distributed Generation unit, DG. The paper demonstrates novel application for the voltage orientation control, also called voltage vector control, so as to precisely control active and reactive power injected by the distributed generation units in a normal operation of the system, (grid-connected mode), and it works as a voltage source in an islanding mode. The adopted topology for the DG is the diode clamped multilevel inverter structure in order to minimize the injected harmonics and get rid of a sophisticated passive filter. The utilization of the voltage vector control scheme is optimized so that the DG unit can precisely control the instantaneous power injected to the power grid. The presented simulation results verify the capability of the suggested control to precisely adjust the active and reactive power based on set-values.