POWER CONVERTER

• US 20160352187A1
• Filed: 01/23/2015
• Published: 12/01/2016
• Est. Priority Date: 02/05/2014
• Status: Active Grant

• Current Assignee: Grundfos Holding A/S (POUL DUE Jensen's FOND)
• Original Assignee: Grundfos Holding A/S (POUL DUE Jensen's FOND)
• Inventors: WOLF, Christian
• Granted Patent: US 10,079,528 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02K 11/0141 Shields associated with casings, enclosures or brackets
• CPC Class Codes: H02K 11/33 Drive circuits, e.g. power electronics H02K11/38 takes precedence
• CPC Class Codes: H02K 5/24 specially adapted for suppression or reduction of noise or vibrations
• CPC Class Codes: H02M 5/297 for conversion of frequency
• CPC Class Codes: H02M 7/003 Constructional details, e.g. physical layout, assembly, wiring or busbar connections
• CPC Class Codes: H02P 27/06 using dc to ac converters or inverters H02P27/05 takes precedence
• CPC Class Codes: H05K 9/0026 integrally formed from metal sheet
• CPC Class Codes: H05K 9/0037 Housings with compartments containing a PCB, e.g. partitioning walls

Abstract

A frequency converter includes an enclosure, in which electrical and electronic components (5, 6, 7, 22) are arranged and which at least partly is designed as a Faraday cage. At least two Faraday cages (4, 9, 15, 29) are provided within the enclosure, in order to improve the electromagnetic compatibility (EMC).

Claims

1. A power converter comprising a frequency inverter, comprising:

an enclosure and

electronic components arranged in the enclosure, wherein the enclosure is at least partly constructed as a Faraday cage and there are at least two Faraday cages in the enclosure.

2. The power converter according to claim 1, wherein the at least two Faraday cages comprise two separate Faraday cages that have a common cage wall.

3. The power converter according to claim 1, wherein the electronic components comprise one or a plurality of components, which form an electromagnetic and/or electrostatic noise source during operation and are arranged in at least one Faraday cage of the at least two Faraday cages, and one or a plurality of components, which are susceptible to receiving electromagnetic and/or electrostatic noise signals, and are arranged in at least one other Faraday cage of the at least two Faraday cages.

4. The power converter according to claim 1, wherein at least the electronic switches of the power circuit of the power converter are arranged in the one Faraday cage.

5. The power converter according to claim 1, wherein the electronic components comprise at least one or a plurality of input and/or output noise filters arranged in separate Faraday cages of the at least two Faraday cages.

6. The power converter according to claim 1, further comprising a feed-through-capacitor in a wall between two the at least two Faraday cages for conducting electric signals and/or electric power from one cage to another cage.

7. The power converter according to claim 1, further comprising at least one capacitor electrically connected with one end to the wall of the Faraday cage, of the at least two Faraday cages, near a feed through hole and at another end connected to a conductor passing from one Faraday cage to another Faraday cage, of the at least two Faraday cages, through this feed through hole.

8. The power converter according to claim 7, wherein the at least one capacitor is electrically connected to the conductor and the wall of that Faraday cage in which a noisy signal occurs or is led to.

9. The power converter according to claim 1, wherein there is a separated Faraday cage, of the at least two Faraday cages, which defines an output filter cage of the power converter, comprising two or more power conductors leading to a motor with at least one capacitor operating between a conductor and the wall of the output filter cage.

10. The power converter according to claim 9, wherein in addition to electrical power conductors, only an input noise filter is arranged in one of the Faraday cages.

11. The power converter according to claim 10, wherein the electric motor, the power conductors between the power converter and electric motor and the power circuit of the power converter are enclosed by a common Faraday cage, of the at least two Faraday cages.

12. The power converter according to claim 11, wherein the common Faraday cage is formed by the metallic motor enclosure or a shielding of the motor, a cable duct and the Faraday cage of the construction of the power converter enclosure.

13. The power converter according to claim 1, wherein the Faraday cages are electrically connected to one another and to ground potential.

14. The power converter according to claim 1, wherein the power converter enclosure has three Faraday cages, of the at least two Faraday cages, one for at least the power circuit, another for an input noise-suppression filter and a further one for an interface circuit of the power converter.

15. The power converter according to claim 1, further comprising a circuit board with the electronic components arranged on the board and connected by traces on the top of the board, wherein at least some of the electronic components are enclosed by at least one Faraday cage, of the at least two Faraday cages, and one conducting layer of the board forms a wall of the Faraday cage.

16. The power converter according to claim 15, wherein the electronic components are arranged in separated areas of the circuit board, one or more separated areas are enclosed by one or more Faraday cages, of the at least two Faraday cages, and one conducting layer of the board forms a wall of the Faraday cages.

17. The power converter according claim 15, wherein the electronic components are arranged on the bottom and the top side of the circuit board which is a multilayer board with Faraday cages, of the at least two Faraday cages, on both sides of the board and a conducting layer inside the board which forms a wall of the Faraday cages on both sides.

18. The power converter according to claim 1 wherein there is a circuit board with electronic components on both sides of the board enclosed by a Faraday cage, of the at least two Faraday cages, the cage walls being on the top and on the bottom of the circuit board electrically connected to one another by wire holes leading through the circuit board.

19. The power converter according to claim 1, wherein the frequency inverter is for an electrical drive motor of a centrifugal pump and the power inverter enclosure is arranged on or on top of the motor and/or pump enclosure.

20. The power converter according to claim 1, wherein the Faraday cage is configured closed such that openings, free spaces, recesses have a clear width of maximal 3.3 mm.

21. The power converter according to claim 1, wherein the distance between electrical and/or electronic components to the wall of the Faraday cage, with the exception of the regions, in which leads are led through, is always greater than 10 mm.