Resonant DC-DC voltage converter (10-2, 10-3, 10-4, 10-5), in particular for an electric or hybrid vehicle, said converter (10-2, 10-3, 10-4, 10-5) comprising a plurality of resonant circuits, each resonant circuit comprising: - a first inductive element (L1, L2, L3), - a resonant capacitor (CR1, CR2, CR3) electrically connected to said first inductive element (L1, L2, L3), - a transformer comprising at least one primary winding (P1, P2, P3) and at least one secondary winding (S1, S2, S3), said first inductive element (L1, L2, L3), the resonant capacitor (CR1, CR2, CR3) and the primary winding (P1, P2, P3) of the transformer being comprised in a branch of the resonant circuit, called the "resonant branch", in which converter (10-2, 10-3, 10-4, 10-5), on the one hand, the first inductive elements (L1, L2, L3) of the resonant circuits are inductively coupled to one another, and on the other hand, the primary windings (P1, P2, P3) of the transformers of the resonant circuits are inductively coupled and electrically connected to one another; and in which converter (10-2, 10-3, 10-4, 10-5): - the resonant branches are electrically connected to the same point, which is called the "first neutral point"; and - the branches, which each comprise one of said secondary windings (S1, S2, S3) of the transformers, are electrically connected to the same point, which is called the "second neutral point"; wherein: the first neutral point is connected to a ground of the DC-DC converter constituting a reference potential of the converter primary-side via a branch comprising at least one impedance configured to store energy and to allow zero-voltage switching of switches of the resonant DC-DC converter, the impedance in particular comprising an inductor in series with a capacitor, and the second neutral point is connected to a ground of the DC-DC converter constituting a reference potential of the converter secondary-side via a branch comprising at least one impedance configured to store energy and to allow zero-voltage switching of switches of the resonant DC-DC converter, the impedance in particular comprising an inductor in series with a capacitor. - a first inductive element (L1, L2, L3), - a resonant capacitor (CR1, CR2, CR3) electrically connected to said first inductive element (L1, L2, L3), - a transformer comprising at least one primary winding (P1, P2, P3) and at least one secondary winding (S1, S2, S3), said first inductive element (L1, L2, L3), the resonant capacitor (CR1, CR2, CR3) and the primary winding (P1, P2, P3) of the transformer being comprised in a branch of the resonant circuit, called the "resonant branch", in which converter (10-2, 10-3, 10-4, 10-5), on the one hand, the first inductive elements (L1, L2, L3) of the resonant circuits are inductively coupled to one another, and on the other hand, the primary windings (P1, P2, P3) of the transformers of the resonant circuits are inductively coupled and electrically connected to one another; and in which converter (10-2, 10-3, 10-4, 10-5): - the resonant branches are electrically connected to the same point, which is called the "first neutral point"; and - the branches, which each comprise one of said secondary windings (S1, S2, S3) of the transformers, are electrically connected to the same point, which is called the "second neutral point"; - the resonant branches are electrically connected to the same point, which is called the "first neutral point"; and - the branches, which each comprise one of said secondary windings (S1, S2, S3) of the transformers, are electrically connected to the same point, which is called the "second neutral point"; wherein: the first neutral point is connected to a ground of the DC-DC converter constituting a reference potential of the converter primary-side via a branch comprising at least one impedance configured to store energy and to allow zero-voltage switching of switches of the resonant DC-DC converter, the impedance in particular comprising an inductor in series with a capacitor, and the second neutral point is connected to a ground of the DC-DC converter constituting a reference potential of the converter secondary-side via a branch comprising at least one impedance configured to store energy and to allow zero-voltage switching of switches of the resonant DC-DC converter, the impedance in particular comprising an inductor in series with a capacitor. the first neutral point is connected to a ground of the DC-DC converter constituting a reference potential of the converter primary-side via a branch comprising at least one impedance configured to store energy and to allow zero-voltage switching of switches of the resonant DC-DC converter, the impedance in particular comprising an inductor in series with a capacitor, and the second neutral point is connected to a ground of the DC-DC converter constituting a reference potential of the converter secondary-side via a branch comprising at least one impedance configured to store energy and to allow zero-voltage switching of switches of the resonant DC-DC converter, the impedance in particular comprising an inductor in series with a capacitor.