Dual-core flow valve current sensor

Abstract

A flow valve current sensor (30) comprising: - a first magnetic core (34) and a first excitation winding (45), a second magnetic core (35) and a second excitation winding (46); - excitation components (37) arranged to produce a first excitation voltage (Ve1) and apply it to the first excitation winding, and to produce a second excitation voltage (Ve2) and apply it to the second excitation winding, the first and second excitation voltages being identical but in opposite phase; - measurement components (38) arranged to produce an output voltage (Vs) representative of the target current from a first measurement voltage (Vm1) and a second measurement voltage (Vm2). Figure 4

Claims

Demands

1. Flow valve current sensor (30), comprising: - a first magnetic core (34) through which extends a measuring conductor (33) on which flows a target current (le), and a first excitation winding (45) which is wound around the first magnetic core; - a second magnetic core (35) through which extends the measuring conductor, and a second excitation winding (46) which is wound around the second magnetic core; - excitation components (37) arranged to produce a first excitation voltage (Vel) and apply it to the first excitation winding, and to produce a second excitation voltage (Ve2) and apply it to the second excitation winding, the first excitation voltage and the second excitation voltage being identical voltages but in opposite phase;- measurement components (38) arranged to produce an output voltage (Vs) representative of the target current from a first measurement voltage (Vml) representative of a first resulting current (II) flowing in the first excitation winding and a second measurement voltage (Vm2) representative of a second resulting current (12) flowing in the second excitation winding.;

2. Flow valve current sensor according to claim 1, wherein the first magnetic core (34) and the second magnetic core (35) are located next to each other and are both positioned between a first plane (PI) and a second plane (P2) which are parallel, the measuring conductor passing through the first plane, then through the first magnetic core to the second plane, then through the second plane, then through the second magnetic core to the first plane.

3. A flow valve current sensor according to claim 2, comprising a printed circuit board (100) including a first conductive layer (101) extending in the first plane (P1), a second conductive layer (102) extending in the second plane (P2), and an insulating layer (103) located between the first conductive layer and the second conductive layer, the first core magnetic and the second magnetic core extending into a thickness of the insulating layer, the first excitation winding, the second excitation winding and the measuring conductor (33) comprising metallized holes (105, 106) extending into the insulating layer between the first conducting layer and the second conducting layer.

4. Flow valve current sensor according to any one of the preceding claims, the flow valve current sensor being intended to measure a current to be measured (Im) and comprising a current divider (31) arranged to produce the target current (le) from the current to be measured (Im), the current divider comprising a first branch (32) and a second branch (33) which is formed by the measuring conductor.

5. Flow valve current sensor according to any one of the preceding claims, wherein: - the first excitation voltage (Vel) comprises a first component (Hl) of frequency f0, a first component (H3) of frequency 3.f0 and a first low frequency component (DC), and the first measurement voltage (Vml) further comprises a first component (H2) of frequency 2.f0; - the second excitation voltage (Ve2) comprises a second component (-H1) of frequency f0 equal to the opposite of the first component of frequency f0, a second component (-H3) of frequency 3.f0 equal to the opposite of the first component of frequency 3.f0, a second low frequency component (DC) equal to the first low frequency component, and the second measurement voltage (Vm2) further comprises a second component (-H2) of frequency 2.f0 equal to the opposite of the first component of frequency 2.f0.

6. A flow valve current sensor according to claim 5, wherein the excitation components (37) comprise a center-tapped transformer (55) forming a phase shifter and comprising a primary winding (57), a first secondary winding (58), a second secondary winding (59), and a mid-tap (60) between the first and second secondary windings, a voltage (Vc) comprising the first frequency component f0 and the first frequency component 3f0 being applied to the primary winding

7.

8. of the center-tapped transformer, a voltage (Vd) including the first low-frequency component being applied to the center tap of the center-tapped transformer (55), the first excitation voltage (Vel) being generated on the first secondary winding (58) and the second excitation voltage (Ve2) being generated on the second secondary winding (59) of the center-tapped transformer (55). Flow valve current sensor according to any one of the preceding claims, wherein the measuring components (38) include a differential amplifier (82) comprising a first input on which the first measuring voltage (Vml) is applied and a second input on which the second measuring voltage (Vm2) is applied. Electrical equipment incorporating a flow valve current sensor according to one of the preceding claims.

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