| 摘要 |
<p>An active current transformer has a primary conductor (Wp) in which a current is to be measured and a secondary conductor (Ws) in which a measuring current is generated in use. A feedback sensor (Wf) provides an induced voltage and an amplifier (A) receives a signal induced in the feedback sensor (Wf) and generates the measuring current in the secondary conductor (Ws). The primary (Wp) and secondary (Ws) conductors are located in first (M1) and second (M2) magnetic circuits respectively, the first and second circuits having a common path over at least a part of their respective lengths. The feedback sensor (Wf) is disposed on the common path of the first and second magnetic circuits so that, in use, the magnetic flux in the second path can be made substantially equal to that in the first path by operation of the amplifier (A) in response to the voltage in the feedback sensor (Wf).</p> |
