| 摘要 |
An electronic device (1) for measuring a differential current (ID) in an electric line (100) having a plurality of conductors, said electronic device comprising:
- a sensing circuit (2) comprising:
- a current transformer (21) having a magnetic core (211) through which the conductors of said electric line pass, a secondary winding (212) and an excitation winding (213) along which an excitation current (IE) circulates to polarize said magnetic core (211);
- an output circuit section (22) electrically connected to said secondary winding (212) and configured to provide a first signal (V1). The electronic device (1) further comprises:
- first signal processing means (3) configured to process said first signal (V1) and provide a second signal (VD) indicative of said differential current (ID);
- second signal processing means (4) configured to process said second signal (VD) and provide a first measurement signal (IDCM) indicative of the absolute value of a time-invariant component of said differential current (ID);
- third signal processing means (5) configured to process said first signal (V1) and provide third and fourth signals (S1, S2) indicating whether said magnetic core (211) operates in a positive and/or in a negative saturation region of the hysteresis loop of said magnetic core;
- fourth signal processing means (6) configured to process said third and fourth signals (S1, S2) and provide a second measurement signal (SDC) indicative of the direction of the time-invariant component of said differential current (ID). |
