The current transformer comprises at least two partial circuits (CBn) each comprising a Rogowski type winding (Cn), each of said the partial circuits being made in the form of an angular portion of a complete circuit (CB) which surrounds at least one primary conductor (10, 10A, 10B, 10C) of the transformer over 360°. The winding (Cn) of each partial circuit (CBn) is constituted by a go winding (Cn0) and by a return winding (Cn1) which extend over the angular extent (θn) of the partial circuit (CBn). For each partial circuit (CBn), the go and return windings are electrically connected in series, both having turns wound in the same direction so as to form a single winding (Cn) which presents a pair of adjacent electrical terminations (T1n, T2n) connected to an acquisition system (7, 7′).