Single-phase multifunctional grid interface converter without grid sincronization

VSI are largely used as grid interface device for DG sources. Extra features have been added to the interface converters, mainly to deal with power quality issues, configuring its use as a multi-function device. In general, the converter acts as a power interface when the DG source is supplying energy and as a power conditioner when the DG source is inactive. In this paper the VSI converter is able to simultaneously operate both as APF and power interface between the grid and the DG source. Also it is possible to operate solely as APF or as an power interface. No synchronization with the grid voltage is required, contributing to the simplicity of the proposed strategy. A single-phase system is simulated validating the strategy.