Patent ID: 7825763

Claim:
A current transformer comprising at least two partial circuits (CB 1 , CB 2 , . . . , CB n , . . . , CB N ) each comprising a Rogowski type winding (C 1 , C 2 , . . . , C n , . . . , C N ), each of said partial circuits being made in the form of an angular portion of a complete circuit (CB) which surrounds at least one primary conductor ( 10 , 10 A, 10 B, 10 C) of the transformer over 360°, said complete circuit having the function of a Rogowski type secondary circuit for the transformer, the winding (C n ) of each partial circuit (CB n ) comprising a go winding (C n0 ) electrically connected to a return winding (C n1 ), said go and return windings being arranged in an interleaved pattern over a significant portion of an angular extent (θ n ) of the partial circuit (CB n ) but substantially less than an entire angular extent of the complete circuit (CB), wherein, for each partial circuit (CB n ), said go and return windings (C n0 , C n1 ) are electrically connected in series, the go winding (C n0 ) comprising turns wound in a first winding direction as the go winding (C n0 ) advances in a first direction along the angular extent (θ n ) of the partial circuit (CB n ) from adjacent a first angular end (E 1n ) towards a second angular end (E 2n ), and the return winding (C n1 ) comprising turns wound in a second winding direction as the return winding (C n1 ) advances in a second direction along the angular extent (θ n ) of the partial circuit (CB n ) from adjacent the second angular end (E 2n ) towards the first angular end (E 1n ), wherein the first and second winding directions are the same, so as to form said winding (C n ) and present a pair of adjacent electrical terminations (T 1n , T 2n ) for each partial circuit (CB n ), the pairs of electrical terminations (T 1n , T 2n ) of said windings (C n ) being connected to an acquisition system ( 7 , 7 ′) designed to produce a complete signal (v s ) which is indicative of an electric current being conducted through the at least one primary conductor ( 10 , 10 A, 10 B, 10 C) of the transformer, and wherein, for each partial circuit (CB n ), one of the two electrical terminations (T 1n , T 2n ) of the winding is electrically connected to a common reference potential (G), while the other termination is electrically connected to an input (E n ) of the acquisition system.