The invention refers to a control method for power converter, that assures operation under Zero Voltage Switching (ZVS) condition in a broad power range in a reliable manner, and which is easy to implement. The control method for operating a DC-DC isolated converter, comprises operating the converter by modifying the switching frequency (fsw) and the phase shift (ϕ) of the converter, to operate the converter under Zero Voltage Switching condition. The invention is especially applicable to multi-port converters, that is, to converters having three or more converters coupled to a common multi-windings transformer.