Volt-second synchronization for magnetic loads
A method and device for connecting a load to an AC power source is arranged to ensure that the volt-second ratings of magnetic devices in the load are not exceeded, in order to limit in-rush currents resulting from saturation of the magnetic devices. In the case where the load is being disconnected from a first AC source and connected to a second AC source, the volt-seconds of the load can be measured and/or calculated during disconnect, in order to delay connection of the load to the second AC source by an amount sufficient to prevent saturation of magnetic devices and thereby ensure volt-second synchronization of the sources.
1 . A method of connecting a load to a source, comprising the steps of:
determining delay intervals based on volt-second characteristics of a load; and
connecting an AC source to the load following said delay intervals.
2 . The method of claim 1 , wherein said load is disconnected from disconnecting source S 1 and connected to connecting source S 2 after said delay intervals, and wherein said volt-seconds are determined based on current and voltage measurements during disconnection of source S 1 from said load.
3 - 27 . (canceled)
28 . A device for connecting a load to a source, comprising:
means for determining delay intervals based on volt-second characteristics of a load; and
means for connecting an AC source to the load following said delay intervals.
29 . The method of claim 28 , wherein said load is disconnected from disconnecting source S 1 and connected to connecting source S 2 after said delay intervals, and wherein said volt-seconds are determined based on current and voltage measurements during disconnection of source S 1 from said load.