Inrush control power supply

Patent metadata

Field	Value
Publication number	US-2017194867-A1
Application number	US-201614987789-A
Country	US
Kind code	A1
Filing date	Jan 5, 2016
Priority date	Jan 5, 2016
Publication date	Jul 6, 2017
Grant date	—

Abstract

In one embodiment, a power apparatus includes a buck converter including a first capacitor, a first inductor and a first switch for connection with a direct current power supply, wherein when the first switch is closed and the buck converter is connected to the direct current power supply, the first capacitor and the first inductor are connected in series to the direct current power supply, a full-bridge inverter including at least four switches including the first switch, a second, third and fourth switch so that the first switch is shared by the inventor and buck converter, the inverter being operative to convert direct current to alternating current by alternating (a) closing the first and fourth switch with the second and third switch open, and (b) closing the second and third switch with the first and fourth switch open, and a transformer to step down an output of the inverter.

First claim

What is claimed is:

1 . A power apparatus comprising:
a buck converter including a first capacitor, a first inductor and a first switch for connection with a direct current power supply, wherein when the first switch is closed and the buck converter is connected to the direct current power supply, the first capacitor and the first inductor are connected in series to the direct current power supply; a full-bridge inverter including at least four switches, the at least four switches including the first switch, a second switch, a third switch and a fourth switch so that the first switch is shared by the full-bridge inventor and the buck converter, the full-bridge inverter being operative to convert direct current to alternating current by alternating: (a) closing the first switch and fourth switch with the second switch and third switch open; and (b) closing the second switch and third switch with the first switch and fourth switch open; and a transformer to step down an output of the full-bridge inverter.

2 . The apparatus according to claim 1 , further comprising a controller operative to open and close switches including the first switch, the second switch, the third switch and the fourth switch.

3 . The apparatus according to claim 2 , wherein:
the controller is operative to close the first switch so that the first capacitor and the first inductor are connected in series to the direct current power supply and the first capacitor charges to a first voltage; and while the controller is operative to close the first switch so that the first capacitor and the first inductor are connected in series to the direct current power supply, the controller is operative to leave the second switch, the third switch and fourth switch open.

4 . The apparatus according to claim 3 , further comprising a fifth switch disposed between the first capacitor and the first inductor, the controller being operative to close the fifth switch while the first capacitor is charging to the first voltage.

5 . The apparatus according to claim 4 , further comprising a sixth switch disposed between the first capacitor and a connection to the direct current power supply, the controller being operative to leave the sixth switch open while the capacitor is charging to the first voltage.

6 . The apparatus according to claim 5 , wherein after the capacitor has charged to the first voltage, the controller is operative to open the first switch and the fifth switch and close the sixth switch causing the capacitor to charge to a second voltage which is greater than the first voltage.

7 . The apparatus according to claim 6 , wherein the first voltage is greater than 95% of the second voltage.

8 . The apparatus according to claim 6 , wherein after the capacitor has charged to the first voltage, the controller is operative to open the first switch and after a first delay open the fifth switch and close the sixth switch causing the capacitor to charge to a second voltage which is greater than the first voltage.

9 . The apparatus according to claim 6 , further comprising at least four diodes including a first diode, a second diode, a third diode and a fourth diode disposed anti-parallel to the first switch, the second switch, the third switch and the fourth switch, respectively.

10 . The apparatus according to claim 9 , wherein after the capacitor has charged to the first voltage while the first switch is open and the fifth switch is still closed, the first inductor is operative to drain to ground via the second diode.

11 . The apparatus according to claim 8 , wherein after a second delay after closing the sixth switch, the controller is operative to leave the sixth switch closed and convert direct current to alternating current by alternating: (a) closing the first switch and fourth switch with the second switch and third switch open; and (b) closing the second switch and third switch with the first switch and fourth switch open.

12 . The apparatus according to claim 11 , wherein the transformer is operative to step down the output of the full-bridge inverter to a third voltage, the apparatus further comprising a rectifier to convert an output of the transformer from alternating current to direct current.

13 . The apparatus according to claim 12 , wherein the rectifier includes a seventh switch and an eighth switch, the controller being operative to alternate: (a) closing the first switch, fourth switch and seventh switch with the second switch, third switch and eighth switch open; and (b) closing the second switch, third switch and eighth switch with the first switch, fourth switch open and seventh switch open.

14 . The apparatus according to claim 6 , wherein after closing the sixth switch, the controller is operative to leave the sixth switch closed and convert direct current to alternating current by alternating: (a) closing the first switch and fourth switch with the second switch and third switch open; and (b) closing the second switch and third switch with the first switch and fourth switch open.

15 . The apparatus according to claim 14 , wherein the transformer is operative to step down the output of the full-bridge inverter to a third voltage, the apparatus further comprising a rectifier to convert an output of the transformer from alternating current to direct current.

16 . The apparatus according to claim 15 , wherein the rectifier includes a seventh switch and an eighth switch, the controller being operative to alternate: (a) closing the first switch, fourth switch and seventh switch with the second switch, third switch and eighth switch open; and (b) closing the second switch, third switch and eighth switch with the first switch, fourth switch open and seventh switch open.

17 . The apparatus according to claim 1 , wherein the transformer is operative to step down the output of the full-bridge inverter to a third voltage, the apparatus further comprising a rectifier to convert an output of the transformer from alternating current to direct current.

18 . A method comprising:
operating a circuit including: a buck converter including a first capacitor, a first inductor and a first switch for connection with a direct current power supply, wherein when the first switch is closed and the buck converter is connected to the direct current power supply, the first capacitor and the first inductor are connected in series to the direct current power supply; a full-bridge inverter including at least four switches, the at least four switches including the first switch, a second switch, a third switch and a fourth switch so that the first switch is shared by the full-bridge inventor and the buck converter, the full-bridge inverter being operative to convert direct current to alternating current by alternating: (a) closing the first switch and fourth switch with the second switch and third switch open; and (b) closing the second switch and third switch with the first switch and fourth switch open; a fifth switch disposed between the first capacitor and the first inductor; and a transformer to step down an output of the full-bridge inverter; and closing the first switch and fifth switch so that the first capacitor and the first inductor are connected in series to the direct current power supply and the first capacitor charges to a first voltage; and while the first switch and fifth switch are closed so that the first capacitor and the first inductor are connected in series to the direct current power supply, leaving the second switch, the third switch and fourth switch open.

Assignees

• Cisco Tech Inc

Inventors

• Li Yang
• Seto Kan
• Grant Michael
• Howard Matt
• Li Ruqi

Classifications

• H02M3/33507 Primary

  with automatic control of the output voltage or current, e.g. flyback converters (H02M3/33561, H02M3/33569 take precedence) · CPC title

• H02M1/0095

  Hybrid converter topologies, e.g. NPC mixed with flying capacitor, thyristor converter mixed with MMC or charge pump mixed with buck · CPC title

• H02M3/33573

  Full-bridge at primary side of an isolation transformer · CPC title

• H02M1/36 Primary

  Means for starting or stopping converters · CPC title

• H02M1/008

  Plural converter units for generating at two or more independent and non-parallel outputs, e.g. systems with plural point of load switching regulators · CPC title