Method for reducing electromagnetic interference radiated from a power supply arrangement
AssigneeSaab AB
InventorBo Nettelblad
Life of this patent
Estimating the term…
Abstract
A method for reducing electromagnetic interference radiated from a power supply arrangement. A plurality of switching mode power supply units are connected to an external device. Each switching mode power supply unit includes a ground point. The radiated electromagnetic interference is reduced by synchronizing a switching frequency of each switching mode power supply unit, such that all of the synchronized switching mode power supply units have an identical switching frequency, thereby reducing the difference in electric potential between the ground points. A corresponding power supply arrangement.
Claims15
A method for reducing electromagnetic interference radiated from a power supply arrangement comprising a plurality of switching mode power supply units connected to an external device, wherein each switching mode power supply unit comprises a ground point, the method comprising:
- connecting each switching mode power supply unit to said external device with conductors, and a ground conductor associated with said conductors, such that a first ground conductor is connected to a first ground point of a first switching mode power supply unit, and a second ground conductor is connected to a second ground point of a second switching mode power supply unit;
- mutually connecting said first and second ground conductors with a first common ground connection associated with the external device, and with a second common ground connection associated with the switching mode power supply units, thereby providing a ground-loop, comprising a first ground conductor, a first common ground connection, a second ground conductor and a second common ground connection;
- and
- synchronizing a switching frequency of each switching mode power supply unit, such that all of said synchronized switching mode power supply units have an identical switching frequency, and such that a common-mode current generated by each switching mode power supply unit is controlled to return mainly in the ground conductor associated with said switching mode power supply unit that generated said common-mode current, thereby reducing a difference in electric potential between said ground points.
A power supply arrangement, comprising:
- a plurality of switching mode power supply units, which are connected to an external device, wherein each switching mode power supply unit comprises a ground point,
- conductors and a ground conductor associated with said conductor, wherein each switching mode power supply unit is connected to said external device with the conductors, and with the ground conductor;
- a first ground conductor connected to a first ground point of a first switching mode power supply unit,
- a second ground conductor connected to a second ground point of a second switching mode power supply unit,
- a first common ground connection associated with the external device and a second common ground connection associated with the switching mode power supply units, wherein said first and second ground conductors are mutually connected with the first common ground connection and with the second common ground connection, thereby providing a ground-loop, comprising first ground conductor, first common ground connection, second ground conductor and second common ground connection;
- and
- a synchronizer configured to synchronize a switching frequency of each switching mode power supply unit, such that all of said synchronized switching mode power supply units have an identical switching frequency, and such that a common-mode current generated by each switching mode power supply unit is controlled to return mainly in the ground conductor associated with said switching mode power supply unit that generated said common-mode current, whereby the difference in electric potential between the ground points is reduced.
Dependencies are inferred from the claim text.