| 摘要 |
<p>The present invention relates to a method and an apparatus for reducing inrush currents in connection with energizing of transformers in a railway system. The railway system including a feeder (1) for supplying trains with alternating voltage, a plurality of transformers (3), and a breaker (5) configured to connect and disconnect the voltage supply to the trains and the transformers. The apparatus comprises a first measuring device (7) for measuring the voltage supplied to the breaker, a second measuring device (8) for measuring the voltage supplied from the breaker, means (12) for detecting when the breaker disconnects the voltage supply to transformers, calculating means (14) for calculating the magnetic remanence in the transformers upon detecting that the voltage supply has been disconnected and to determine whether the calculated magnetic remanence is positive or negative, and connecting means (16) for connecting the breaker upon energizing the railway system. The connecting means is configured to connect the breaker at a point in time on or close to a positive peak of the voltage supplied to the breaker if the magnetic remanence is negative, and to connect the breaker at a point in time on or close to a negative peak of the voltage supplied to the breaker if the magnetic remanence is positive.</p> |
