| 摘要 |
<p>The aim of the invention is to construct a current and phase transducer in a galvanic separated circuit where the electro-optical current transducer is connected to the secondary coil of the current transformer and via an optic fibre cable to the receiver. Appropriate insulation resistivity is provided by selecting the correct cable length. The primary transformer coil (1) is made from a high-voltage conductor (11) where current and phase are measured. The secondary coil is connected via two parallel circuits: the bridging circuit (B) and the measuring circuit (A). The measuring circuit (A) features a resistor (2), which is provided to determine the saturation current of the ferromagnetic transformer (1) core and a parallel diode bridge (3) which is bridged by an emitting electro-optical transducer (4) -- LED diode. The diode bridge (3) rectifies both half-sines of the alternating current in the conductive direction of the LED diode (4) so that at the reception side the signal is monitored across the whole period. The diode bridge (6) and the diodes (7), (8), (9) connected in series are provided to equalise the U/I characteristics of both parallel connected circuits (A) and (B). This way the light response of the transducer is improved at a minor current in the primary circuits.</p> |
