Power converting device and control method thereof for providing backup power source

Patent metadata

Field	Value
Publication number	US-10505388-B2
Application number	US-201615375181-A
Country	US
Kind code	B2
Filing date	Dec 12, 2016
Priority date	Jun 17, 2016
Publication date	Dec 10, 2019
Grant date	Dec 10, 2019

Abstract

A power converting device includes an AC/DC converter, a switch, and a controlling unit. The AC/DC converter converts AC power into a DC voltage, and provides the DC voltage to a load. The switch is coupled to a backup power source. The controlling unit receives the DC voltage. If the DC voltage is less than a predetermined voltage or a decrease of the DC voltage is greater than a predetermined percentage of the DC voltage and the controlling unit receives a voltage command signal of the backup power source, the controlling unit turns on the switch for providing the backup power source to the load.

First claim

What is claimed is:

1. A power converting device comprising:
an AC/DC converter converting AC power to a DC voltage, and providing the DC voltage to a load;
a switch coupled to a backup power source; and
a controlling unit detecting the DC voltage provided to the load, and preforming a determination of whether the DC voltage provided to the load is less than a predetermined voltage or whether a decrease of the DC voltage provided to the load is greater than a predetermined percentage of the DC voltage provided to the load,
wherein in response to the determination indicating that the DC voltage provided to the load is less than the predetermined voltage or the decrease of the DC voltage provided to the load is greater than a predetermined percentage of the DC voltage provided to the load and in response to a voltage command signal corresponding to the backup power source received by the controlling unit, the controlling unit turns on the switch for providing the backup power source to the load.

2. The power converting device of claim 1 , wherein the controlling unit comprises:
a judging unit making a judgment on the DC voltage provided to the load, wherein if the DC voltage provided to the load is less than the predetermined voltage or the decrease of the DC voltage provided to the load is greater than the predetermined percentage of the DC voltage provided to the load and the judging unit receives the voltage command signal, the judging unit outputs a judging signal; and
a driver receiving the judging signal and outputting a drive signal to the switch according to the judging signal, the switch being turned on according to the drive signal for providing the backup power source to the load.

3. The power converting device of claim 1 , further comprising:
a current limiter coupled between the switch and an output terminal of the AC/DC converter and used for preventing the AC/DC converter from supplying power to the backup power source through the switch.

4. The power converting device of claim 1 , further comprising:
at least one diode comprising:
an anode terminal coupled to the switch; and
a cathode terminal coupled to an output terminal of the AC/DC converter.

5. The power converting device of claim 1 , further comprising:
a current limiter coupled between the switch and an output terminal of the AC/DC converter and used for preventing the backup power source from supplying power to the AC/DC converter or the controlling unit through the switch.

6. The power converting device of claim 1 , further comprising:
at least one diode comprising:
an anode terminal coupled to an output terminal of the AC/DC converter; and
a cathode terminal coupled to the switch.

7. The power converting device of claim 1 , wherein the power converting device further comprises:
a voltage judging unit detecting a voltage of the backup power source, wherein if the voltage of the backup power source is within a range of threshold voltages, the voltage judging unit outputs the voltage command signal.

8. The power converting device of claim 7 , wherein the voltage judging unit comprises:
a high-voltage judging unit determining whether or not the voltage of the backup power source exceeds a predetermined upper limit value of the range of threshold voltages; and
a low-voltage judging unit determining whether or not the voltage of the backup power source is lower than a predetermined lower limit value of the range of threshold voltages;
wherein if the voltage of the backup power source does not exceed the predetermined upper limit value and is not lower than the predetermined lower limit value, the voltage judging unit outputs the voltage command signal.

9. The power converting device of claim 8 , wherein the voltage judging unit does not output the voltage command signal if the voltage of the backup power source exceeds the predetermined upper limit value or is lower than the predetermined lower limit value.

10. The power converting device of claim 8 , wherein the low-voltage judging unit comprises:
a low-voltage disconnect hysteresis controller continuously outputting the voltage command signal when the voltage of the backup power source is within a buffer range lower than the predetermined lower limit value to allow the controlling unit to continuously turn on the switch for providing the backup power source to the load.

11. The power converting device of claim 7 , wherein the voltage judging unit comprises:
a high-voltage judging unit comprising:
a first zener diode, a cathode terminal of the first zener diode being coupled to the backup power source; and
a first transistor, a control terminal of the first transistor being coupled to an anode terminal of the first zener diode, a first terminal of the first transistor being grounded;

a low-voltage judging unit comprising:
a second zener diode, a cathode terminal of the second zener diode being coupled to the backup power source;
a second transistor, a control terminal of the second transistor being coupled to an anode terminal of the second zener diode and a second terminal of the first transistor, a first terminal of the second transistor being grounded; and
a third transistor, a control terminal of the third transistor being couple to a second terminal of the second transistor, a first terminal of the third transistor, and the backup power source, a second terminal of the third transistor being coupled to the second terminal of the first transistor and an output terminal.

12. The power converting device of claim 11 , wherein a breakdown voltage of the first zener diode is greater than a breakdown voltage of the second zener diode.

13. The power converting device of claim 11 , wherein the voltage judging unit further comprises:
a low-voltage disconnect hysteresis controller comprising:
a third zener diode, an anode terminal of the third zener diode being coupled to the second terminal of the first transistor, a cathode terminal of the third zener diode being coupled to the output terminal, wherein a breakdown voltage of the second zener diode is greater than a breakdown voltage of the third zener diode.

14. A control method of a power converting device comprising:
converting AC power into a DC voltage and providing the DC voltage to a load by an AC/DC converter;
detecting the DC voltage provided to the load, and preforming a determination of whether or not the DC voltage provided to the load is less than a predetermined voltage or whether or not a decrease of the DC voltage provided to the load is greater than a predetermined percentage of the DC voltage provided to the load by a controlling unit; and
turning on a switch by the controlling unit for providing a backup power source to the load in response to the determination indicating that the DC voltage provided to the load is less than the predetermined voltage or the decrease of the DC voltage provided to the load is greater than the predetermined percentage of the DC voltage provided to the load and in response to a voltage command signal corresponding to the backup power source received by the controlling unit.

15. The control method of claim 14 , wherein determining whether or not the DC voltage provided to the load is less than the predetermined voltage or determining whether or not the decrease of the DC voltage provided to the load is greater than the predetermined percentage of the DC voltage provided to the load by the controlling unit comprises:
making a judgment on the DC voltage provide to the load by a judging unit of the controlling unit, if the controlling unit determines that the D

Assignees

• Delta Electronics Inc

Inventors

• Tu Kuan-Hsien
• Peng Yung-Wei
• CHIANG So-Huan

Classifications

• H02J7/865

  Battery or charger load switching, e.g. concurrent charging and load supply (H02J7/50 takes precedence) · CPC title

• H02J9/061 Primary

  for DC powered loads · CPC title

• H02M7/12

  using discharge tubes with control electrode or semiconductor devices with control electrode · CPC title

• H02J7/0068

  Electricity · mapped topic

• H02M7/04

  by static converters · CPC title