| 摘要 |
A measuring transformer compares a current flowing through a conductor to a reference current. In one embodiment, the measuring transformer includes a magnetic circuit formed by a toroidal core, a conductor through which the current to be measured flows and which is enclosed by the toroidal core, a secondary winding arranged on the toroidal core, and a magnetic field measuring element which is arranged in a gap of the toroidal core and which is sensitive to the magnetic field in the gap. In order to be able to reliably detect even high-frequency deviations from the reference current, the measuring transformer includes a reference presetting unit for acting on the secondary winding with the reference current. According to one embodiment, the measuring transformer is used for measuring an output current of an inverter for a wind power installation. |
