| 摘要 |
The invention relates to an arrangement for reducing a magnetic unidirectional flux component (ΦDC) in the core (1) of a transformer, comprising: a measurement apparatus (7), which provides a measurement signal (8) corresponding to the magnetic unidirectional flux component (ΦDC), a compensation winding (K), which is magnetically coupled to the core (1) of the transformer, wherein magnetic flux flowing in the core (1) induces a voltage (UK) in the compensation winding, a switch device (5) which is arranged electrically in series together with the compensation winding (K) in a current path (6), a control device, which controls the switch device (5) by means of a control parameter (11) such that the switch device (5) can be switched to a conductive state at an activation time, wherein the activation time is dependent on the measurement signal (8) and is network-synchronous; that is, phase-synchronous to the voltage in the compensation winding (K), whereby a current is supplied to the compensation winding (K), the effect of which is directed against the unidirectional flux component (ΦDC), wherein the switch unit (5) is formed by a magnetic core (10) and a winding arrangement (3, 20) which is magnetically coupled to said core (10), the control parameter (11) is supplied to the winding arrangement (3, 20) such that the magnetic saturation state of the core (10) is variable, whereby the conductive state of the switch unit (5) can be produced. |
