A mechatronic circuit-breaker device adapted to break an electrical current flowing through electrical power transmission means, the device comprising: - a main branch comprising at least one main module (10.1, 10.2, 10.n) comprising at least one sub-branch (10.11, 10.12, 10.1n) comprising at least one mechanical switch-disconnector connected in series with at least one breaker cell (101a; 101b) constituted of at least one power semiconductor element with controlled conduction rate (1010a; 1010b); - an auxiliary branch electrically in parallel with the main branch and comprising: • at least one first sub-branch (11.1, 11.2, 11.3), called the timing sub-branch, and comprising at least one first breaker cell comprising a plurality of power thyristors in cascade (111a, 112a, 113a; 111b, 112b, 113b), at least one of the timing sub-branches further comprising at least one first switching-assistance module with at least one first capacitor, electrically in parallel with its discharge resistance and a voltage surge limiter; • a second sub-branch (11.4), called the arming sub-branch, electrically in parallel with the timing sub-branch and comprising at least one second breaker cell constituted of a plurality of power thyristors in cascade (114a; 114b) and at least one second switching-aid module with at least one second capacitor electrically in parallel with its discharge resistor; and - at least one main voltage surge limiter electrically in parallel with the main branch. - a main branch comprising at least one main module (10.1, 10.2, 10.n) comprising at least one sub-branch (10.11, 10.12, 10.1n) comprising at least one mechanical switch-disconnector connected in series with at least one breaker cell (101a; 101b) constituted of at least one power semiconductor element with controlled conduction rate (1010a; 1010b); - an auxiliary branch electrically in parallel with the main branch and comprising: • at least one first sub-branch (11.1, 11.2, 11.3), called the timing sub-branch, and comprising at least one first breaker cell comprising a plurality of power thyristors in cascade (111a, 112a, 113a; 111b, 112b, 113b), at least one of the timing sub-branches further comprising at least one first switching-assistance module with at least one first capacitor, electrically in parallel with its discharge resistance and a voltage surge limiter; • a second sub-branch (11.4), called the arming sub-branch, electrically in parallel with the timing sub-branch and comprising at least one second breaker cell constituted of a plurality of power thyristors in cascade (114a; 114b) and at least one second switching-aid module with at least one second capacitor electrically in parallel with its discharge resistor; and • at least one first sub-branch (11.1, 11.2, 11.3), called the timing sub-branch, and comprising at least one first breaker cell comprising a plurality of power thyristors in cascade (111a, 112a, 113a; 111b, 112b, 113b), at least one of the timing sub-branches further comprising at least one first switching-assistance module with at least one first capacitor, electrically in parallel with its discharge resistance and a voltage surge limiter; • a second sub-branch (11.4), called the arming sub-branch, electrically in parallel with the timing sub-branch and comprising at least one second breaker cell constituted of a plurality of power thyristors in cascade (114a; 114b) and at least one second switching-aid module with at least one second capacitor electrically in parallel with its discharge resistor; and - at least one main voltage surge limiter electrically in parallel with the main branch.