Power conversion systems and an associated control methods are disclosed. The system includes a plurality of converters connected in parallel on an AC side, each converter includes an AC side for being coupled to a power grid, a DC side for being coupled to a DC source, and a first terminal and a second terminal on said DC side. The outputs on the AC side of all the converters are connected to a common output point, the first terminals of the different converters of the system being grounded, and the second terminals of said converters being independent to one another. Each source is therefore adapted and configured to work independently of the rest of the sources.