Power-saving line interactive uninterruptible power system

• US 8,314,593 B2
• Filed: 10/22/2009
• Issued: 11/20/2012
• Est. Priority Date: 08/28/2009
• Status: Active Grant

• Current Assignee: Cyberpower Systems Incorporated
• Original Assignee: Cyberpower Systems Incorporated
• Inventors: Yeh, Shou-Ting, Lin, Yung-Mei
• Primary Examiner(s): Tso, Edward
• Assistant Examiner(s): PIGGUSH, AARON C
• Application Number:
  US12/603,952
• Publication Number:
  US 20110095727A1
• Time in Patent Office: 1,125 Days
• Field of Search: 320/107, 320/128, 320/135, 320/138, 320/145, 320/163
• US Class Current: 320/128
• CPC Class Codes: H02J 9/062 for AC powered loads
• CPC Class Codes: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y04S 20/20 End-user application control systems

Abstract

A power-saving line interactive UPS has a power switch set, a low-frequency transformer, a full-bridge circuit, a main controller, a charge and discharge mode controller, a rechargeable battery and a high-frequency charging circuit. The high-frequency circuit is connected between an AC power input terminal and the rechargeable battery to convert the AC power into a DC power and charge the rechargeable battery. Therefore, when the AC power is normally supplied and the power capacity of the rechargeable battery is not full, the high-frequency charging circuit is activated to charge the rechargeable battery without charging the rechargeable battery through the low-frequency transformer and the full-bridge switching circuit, thereby effectively reducing overall power consumption.

Claims

1. A power-saving line interactive UPS, comprising:

a power switch set connected to an AC power input terminal adapted to connect to an AC power supply to determine if the AC power supply supplies power to a load;

a low-frequency transformer having two windings, one winding adapted to connect to the load and adapted to connect to the AC power supply;

a full-bridge switching circuit having two half-bridge switching circuits having serially connected nodes connected to the other winding of the low-frequency transformer;

a main controller connected to the power switch set;

a charge and discharge mode controller connected to the main controller and the full-bridge switching circuit and activating the full-bridge switching circuit to enter a charging mode or a discharging mode in accordance with a charge command or a discharge command from the main controller;

a rechargeable battery connected to the full-bridge switching circuit and performing charging or discharging through the full-bridge switching circuit; and

a high-frequency charging circuit connected between the AC power input terminal and the rechargeable battery and converting the AC power into a DC power to charge the rechargeable battery; and

a switch connected between one of the two windings of the low-frequency transformer and the power switch set and controlled by the charge and discharge mode controller to switch on or off, wherein

when the main controller detects that a current power capacity of the rechargeable battery is full and outputs a signal to the charge and discharge mode controller, the charge and discharge mode controller switches off the switch to disconnect the low-frequency transformer with the AC power supply and the load and the high-frequency charging circuit is activated to directly convert the AC power into the DC power to charge the rechargeable battery if a current power capacity of the rechargeable battery is not full but above a low power threshold; and

when the main controller detects that a current power capacity of the rechargeable battery drops to the low power threshold and outputs a signal to the charge and discharge mode controller, the charge and discharge mode controller switches on the switch to connect the low-frequency transformer with the AC power supply and the load and charges the rechargeable battery through the low-frequency transformer and the full-bridge switching circuit until the rechargeable battery reaches a full power capacity.

2. The power-saving line interactive UPS as claimed in claim 1, wherein the high-frequency charging circuit comprises a rectifier and a high-frequency charger.

3. The power-saving line interactive UPS as claimed in claim 2, wherein the switch is a relay.

4. The power-saving line interactive UPS as claimed in claim 2, wherein the switch is a MOSFET.

5. The power-saving line interactive UPS as claimed in claim 2, wherein the switch is a TRIAC.

6. The power-saving line interactive UPS as claimed in claim 2, wherein the switch is an IGBT.

7. The power-saving line interactive UPS as claimed in claim 1, wherein the switch is a relay.

8. The power-saving line interactive UPS as claimed in claim 1, wherein the switch is a MOSFET.

9. The power-saving line interactive UPS as claimed in claim 1, wherein the switch is a TRIAC.

10. The power-saving line interactive UPS as claimed in claim 1, wherein the switch is an IGBT.