Multi-level converter device for at least converting a chopped AC voltage available at a chopped voltage point into at least five DC voltage levels (-U/2, -U/4, REF, U/4, U/2) available on DC voltage lines, said lines including a reference voltage line (5; 70) and as many lines (6, 7; 71-75) having positive voltage levels as there are lines having negative voltage levels (8, 9), said device comprises two separate switching units (UC1, UC2; 61) for converting alternations in said respectively positive and negative chopped voltage into at least two respectively positive and negative DC voltage levels, said switching units being connected to said reference voltage line (5; 70) and to the DC voltage lines (6-9; 71-75) having a positive voltage level and a negative voltage level, respectively, and characterized in that each switching unit comprises a chopping point (S1, S2) connected to said chopped voltage point by way of permutating means, and switching groups (41-48; 91-96) connected between said lines to which said switching unit is connected and said chopping point, each switching unit (UC1, UC2) comprises: - a maximum voltage branch (31, 32) connected directly between the chopping point (S1, S2) of said switching unit and the DC voltage line (6, 8; 75) connected to said switching unit having an extreme voltage level, said maximum voltage branch being provided with a first switching group (41, 42; 95), - at least one intermediate voltage branch (33, 34, 91-94) connected directly between said chopping point (S1, S2) and the at least one DC voltage line (7, 9; 71-74) connected to said switching unit having an intermediate voltage level, said at least one intermediate voltage branch being provided with a second switching group (43, 44; 91-94), and - a minimum voltage branch (35, 36) connected directly between said chopping point (S1, S2) and the reference voltage line (5, 70), said minimum voltage branch being provided with a third switching group (45, 46; 96), said switching groups (41-46; 91-96) of each branch (31-36; 31, 35, 81-84) enable at least electrical energy to be transferred from the chopping point (S1, S2) to the DC voltage lines (5-9; 70-75) to which said branches are connected in order to regulate the voltage levels on said lines, and said second switching group (43, 44; 91-94) of each intermediate voltage branch (33, 34; 81, 84) and of each switching unit (UC1, UC2; 61) is designed to enable a current to be conducted in at least a first direction when the amplitude of the voltage on the chopping point (S1, S2) of said switching unit is greater than the amplitude of the voltage on the line to which said branch is connected, and to block said current regardless of the amplitude of the voltage on the chopping point. - a maximum voltage branch (31, 32) connected directly between the chopping point (S1, S2) of said switching unit and the DC voltage line (6, 8; 75) connected to said switching unit having an extreme voltage level, said maximum voltage branch being provided with a first switching group (41, 42; 95), - at least one intermediate voltage branch (33, 34, 91-94) connected directly between said chopping point (S1, S2) and the at least one DC voltage line (7, 9; 71-74) connected to said switching unit having an intermediate voltage level, said at least one intermediate voltage branch being provided with a second switching group (43, 44; 91-94), and - a minimum voltage branch (35, 36) connected directly between said chopping point (S1, S2) and the reference voltage line (5, 70), said minimum voltage branch being provided with a third switching group (45, 46; 96),