A current sensor system (1500; 1600) for measuring an AC electrical current, comprising: - a busbar (1501; 1601) comprising a beam shaped portion (1590; 1690) having a predefined length (Lc) extending in a first direction, and a predefined thickness in a second direction, and a predefined width (Wp) in a third direction perpendicular to the first direction; - a sensor device (1502; 1602) comprising two sensor elements (H1, H2) spaced apart by a predefined distance (dx) along the third direction; wherein the sensor device (1502; 1602) is positioned relative to the busbar such that a reference point of the sensor device situated in the middle between the two sensor elements (H1, H2) is located at a first distance (Xs) measured in the third direction from a symmetry plane (Ω) of the beam shaped portion, and is located at a second distance (Zs) from the busbar measured in the second direction; wherein the predefined width (Wp) of the beam shaped portion is 2.0 to 4.0 mm; and wherein the predefined length (Lc) of the beam shaped portion is at least 4.0 mm; and wherein the predefined distance (dx) between the two sensor elements is a value in the range from 1.0 to 3.0 mm; and wherein the first distance (Xs) is a value in the range from 0.0 mm to 3.0 mm; characterized in that each sensor element is configured for measuring a magnetic field component (Bz1, Bz2) oriented in the second direction; the sensor device is configured for determining a difference between these magnetic field components (Bz1, Bz2), and for determining said AC current based on said difference; and wherein the second distance (Zs) is a value in the range from 0.5 mm to 4.0 mm. - a busbar (1501; 1601) comprising a beam shaped portion (1590; 1690) having a predefined length (Lc) extending in a first direction, and a predefined thickness in a second direction, and a predefined width (Wp) in a third direction perpendicular to the first direction; - a sensor device (1502; 1602) comprising two sensor elements (H1, H2) spaced apart by a predefined distance (dx) along the third direction; wherein the sensor device (1502; 1602) is positioned relative to the busbar such that a reference point of the sensor device situated in the middle between the two sensor elements (H1, H2) is located at a first distance (Xs) measured in the third direction from a symmetry plane (Ω) of the beam shaped portion, and is located at a second distance (Zs) from the busbar measured in the second direction; wherein the predefined width (Wp) of the beam shaped portion is 2.0 to 4.0 mm; and wherein the predefined length (Lc) of the beam shaped portion is at least 4.0 mm; and wherein the predefined distance (dx) between the two sensor elements is a value in the range from 1.0 to 3.0 mm; and wherein the first distance (Xs) is a value in the range from 0.0 mm to 3.0 mm; each sensor element is configured for measuring a magnetic field component (Bz1, Bz2) oriented in the second direction; the sensor device is configured for determining a difference between these magnetic field components (Bz1, Bz2), and for determining said AC current based on said difference; and wherein the second distance (Zs) is a value in the range from 0.5 mm to 4.0 mm.