SINGLE-BATTERY POWER TOPOLOGIES FOR ONLINE UPS SYSTEMS

• US 20130026835A1
• Filed: 07/28/2011
• Published: 01/31/2013
• Est. Priority Date: 07/28/2011
• Status: Active Grant

• Current Assignee: Schneider Electric IT Corporation (Schneider Electric SE)
• Original Assignee: American Power Conversion Corporation (Schneider Electric SE)
• Inventors: Ghosh, Rajesh, Klikic, Damir, Lipare, Mahendrakumar
• Granted Patent: US 9,024,476 B2
• Time in Patent Office: Days
• US Class Current: 307/66
• CPC Class Codes: H02J 9/062 for AC powered loads
• CPC Class Codes: H02M 1/10 Arrangements incorporating converting means for enabling loads to be operated at will from different kinds of power supplies, e.g. from ac or dc

Abstract

A power converter includes a first power input to receive AC input power, a second power input to receive backup power, a first DC bus configured to provide a positive DC output voltage, a second DC bus configured to provide a negative DC output voltage, and a power conversion circuit coupled to the first DC bus and the second DC bus. The power conversion circuit has an inductor, a first switch device coupled in series with the inductor, a second switch device coupled in series with the first switch device, and a bypass relay coupled in parallel with the second switch device. The power conversion circuit is switchably coupled to the first power input and the second power input, and is operable to charge the inductor and generate the positive and negative DC output voltages.

Claims

1. A power converter, comprising:

a first power input to receive AC input power;

a second power input to receive backup power;

a first DC bus configured to provide a positive DC output voltage;

a second DC bus configured to provide a negative DC output voltage; and

a power conversion circuit, coupled to the first DC bus and the second DC bus, having an inductor, a first switch device coupled in series with the inductor, a second switch device coupled in series with the first switch device, and a bypass relay coupled in parallel with the second switch device, the power conversion circuit switchably coupled to the first power input and the second power input, the power conversion circuit operable to charge the inductor and generate the positive and negative DC output voltages, the power conversion circuit configured to;

in a line mode of operation and during a positive portion of the AC input power, charge the inductor through a first current path of the power conversion circuit that includes the first switch device, the second switch device, the first power input and the inductor;

in the line mode of operation and during a negative portion of the AC input power, charge the inductor through a second current path of the power conversion circuit that includes the first switch device, the second switch device, the first power input and the inductor; and

in a backup mode of operation, generate the negative DC output voltage through a third current path of the power conversion circuit that includes the second power input, the inductor, the first switch device and the bypass relay, wherein the third current path bypasses the second switch device through the bypass relay.

2. The power converter of claim 1, wherein the power conversion circuit includes a boost converter circuit operable to transfer power stored in the inductor to the first DC bus and the second DC bus.

3. The power converter of claim 2, further comprising a neutral input and a third switch device coupled to the inductor, wherein the power conversion circuit is further configured to, in the backup mode of operation, charge the inductor through a fourth current path of the power conversion circuit that includes the inductor and the third switch device.

4. The power converter of claim 3, further comprising a fourth switch device coupled to the neutral input, wherein the power conversion circuit is further configured to generate the positive DC output voltage through a fifth current path of the power conversion circuit that includes the inductor and the fourth switch.

5. The power converter of claim 4, further comprising a battery coupled to the second power input.

6. The power converter of claim 5, further comprising a battery charging circuit coupled to the battery, the first DC bus and the second DC bus, wherein the battery charging circuit is configured to charge the battery from at least one of the first DC bus and the second DC bus.

7. The power converter of claim 6, wherein the inductor is a first inductor, and wherein the battery charging circuit includes a second inductor coupled between the battery and at least one of the first DC bus and the second DC bus.

8. The power converter of claim 4, further comprising a DC-AC inverter circuit coupled to the first DC bus and the second DC bus and configured to convert the positive DC output voltage and the negative DC output voltage into an AC output voltage.

9. A power converter, comprising:

a first power input to receive AC input power;

a second power input to receive backup power;

a power output to provide a positive DC output voltage and a negative DC output voltage each derived from at least one of the AC input power and the backup power;

an inductor switchably coupled to the first power input and the second power input; and

means for generating the positive DC output voltage and the negative DC output voltage using energy stored in the inductor.

10. The power converter of claim 9, further comprising a battery coupled to the second power input.

11. The power converter of claim 10, further comprising means for charging the battery using at least one of the positive DC output voltage and the negative DC output voltage.

12. The power converter of claim 9, further comprising a first switch device coupled in series with the inductor, a second switch device coupled in series with the first switch device, and a bypass relay coupled in parallel with the second switch device, wherein the bypass relay is configured to bypass the second switch device in a backup mode of operation.

13. A method of providing power to a load, the method comprising:

detecting a presence of AC input power from a primary power source;

responsive to detecting the presence of the AC input power and during a positive portion of the AC input power, storing energy from the primary power source in an inductor through a first current path of a power conversion circuit that includes a first switch device, a second switch device, and the inductor;

responsive to detecting the presence of the AC input power and during a negative portion of the AC input power, storing energy from the primary power source in the inductor through a second current path of the power conversion circuit that includes a first switch device, a second switch device and the inductor;

detecting a loss of the AC input power from the primary power source;

responsive to detecting the loss of the AC input power, closing a bypass relay coupled in parallel to the second switch device to bypass the second switch device; and

responsive to detecting the loss of the AC input power, storing energy from a secondary power source in the inductor, and converting the energy stored in the inductor to a negative DC output voltage through a third current path of the power conversion circuit that excludes the second switch device.

14. The method of claim 13, further comprising, responsive to detecting the loss of the AC input power, storing energy from the secondary power source in the inductor, and converting the energy stored in the inductor to a positive DC output voltage through a fourth current path of the power conversion circuit that excludes the first switch device and the second switch device.

15. The method of claim 13, wherein the power conversion circuit includes a boost converter circuit, and wherein the method further comprises converting power stored in the inductor into a positive DC output voltage using the boost converter circuit.

16. The method of claim 15, wherein the boost converter circuit is a first boost converter circuit, wherein the power conversion circuit includes a second boost converter circuit, and wherein the method further comprises converting power stored in the inductor into a negative DC output voltage using the second boost converter circuit.