Controlling method of a battery mode of a uninterruptible power supply for an active power factor corrected load

• US 20100237701A1
• Filed: 03/18/2009
• Published: 09/23/2010
• Est. Priority Date: 03/18/2009
• Status: Active Grant

• Current Assignee: Cyberpower Systems Incorporated
• Original Assignee: Cyberpower Systems Incorporated
• Inventors: Yeh, Shou-Ting, Lin, Yung-Mei
• Granted Patent: US 7,982,339 B2
• Time in Patent Office: Days
• US Class Current: 307/66
• CPC Class Codes: H02J 9/061 for DC powered loads
• CPC Class Codes: H02M 1/4225 using a non-isolated boost converter
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
• CPC Class Codes: Y02P 80/10 Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier

Abstract

A controlling method of a battery mode of a UPS for an active PFC power supply has following acts of monitoring the AC power source and determining whether the AC power source is terminated or not; wherein if a determining result is positive go to next act; and switching to the battery mode and outputting a square wave power source. The square wave power source has a period, and each half of the period is alternately constituted by at least two ON times and at least two OFF times, and each of the at least two OFF times is equal or smaller than a hold-up time of the active PFC load. Therefore, the voltage of the bulk capacitor of the active PFC power supply at discharge condition is not lower than the low threshold voltage, since the OFF time of the square wave signal will be kept to be equal or less than the hold-up time.

Claims

1. A controlling method of a battery mode of a UPS for an active PFC load, wherein the UPS has an inverter, a transformer, a battery charger and a battery set and the controlling method comprises acts of:

monitoring the AC power source and determining whether the AC power source is terminated or not;

wherein if a determining result is positive go to next act; and

switching to the battery mode and outputting a square wave power source, wherein the square wave power source has a period, and each half of the period is alternately constituted by at least two ON times and at least two OFF times, and each of the at least two OFF times is equal or smaller than a hold-up time of the active PFC load.

2. The controlling method as claimed in claim 1, wherein the time of the OFF time is less than 8 ms.

3. The controlling method as claimed in claim 1, wherein

the transformer having a primary winding and a secondary winding, wherein the primary winding connected to the AC power source;

the inverter has a controller and two power transistors each of which has a controlling terminal connected to the controller, wherein the two power transistors are connected between the secondary winding and the battery set, and the controller outputs two PWM signals to the controlling terminals of the corresponding power transistors to alternatively switch two power transistors, wherein each PWM signal has a pulse width consisted by multiple widths of multiple pulses and a time gap between the two widths of the pulses is equal or less than the hold-up time.

4. The controlling method as claimed in claim 1, wherein the hold-up time is at least 8 ms.