Energy storage device and method thereof for supplying power

Patent metadata

Field	Value
Publication number	US-12155249-B2
Application number	US-202117388038-A
Country	US
Kind code	B2
Filing date	Jul 29, 2021
Priority date	Jul 6, 2021
Publication date	Nov 26, 2024
Grant date	Nov 26, 2024

Abstract

An energy storage device and a method thereof are provided. The power transfer circuit transfers a DC voltage provided by a battery module into an AC output voltage to provide the AC output voltage to an output end of the power transfer circuit for providing power to a load. When the AC output voltage is at a default phase, the power transfer circuit is disabled in a default period, and whether the energy storage device may be shut down is determined according to a voltage difference of the AC output voltage sensed by a sensing circuit during the default period.

First claim

What is claimed is:

1. An energy storage device, comprising:
a battery module providing a first DC voltage;
a power transfer circuit coupled to the battery module and transferring the first DC voltage into an AC output voltage to provide the AC output voltage to an output end of the power transfer circuit for providing power to a load;
a sensing circuit coupled to the output end of the power transfer circuit to sense the AC output voltage;
a control circuit coupled to the power transfer circuit and the sensing circuit; and
a switch circuit coupled to the output end of the power transfer circuit, the control circuit, and the load and controlled by the control circuit to enter an off-state during a first detection period and enter an on-state during a second detection period, wherein the control circuit disables the power transfer circuit in the default period when the AC output voltage is at the default phase during the first detection period and the second detection period, respectively to obtain a first corresponding voltage difference value of the AC output voltage during the first detection period and a second corresponding voltage difference value of the AC output voltage during the second detection period, and the control circuit determines whether to shut down the energy storage device according to a difference between the first voltage difference value and the second voltage difference value.

2. The energy storage device according to claim 1 , wherein the power transfer circuit comprises:
an output capacitor coupled to the output end of the power transfer circuit, wherein the AC output voltage is generated on the output capacitor.

3. The energy storage device according to claim 2 , wherein the power transfer circuit comprises:
a DC/DC converter coupled to the battery module and the control circuit to transfer the first DC voltage into a second DC voltage; and
a DC/AC inverter coupled to the DC/DC converter, wherein the DC/AC inverter comprises the output capacitor, and the DC/AC inverter transfers the second DC voltage into the AC output voltage.

4. The energy storage device according to claim 3 , wherein the control circuit turns off a plurality of voltage conversion switches comprised in the DC/AC inverter during the default period to disable the power transfer circuit.

5. The energy storage device according to claim 1 , wherein the control circuit determines a resistance value of the load according to a voltage difference of the AC output voltage and determines whether to shut down the energy storage device according to the resistance value of the load.

6. The energy storage device according to claim 5 , wherein when the resistance value of the load is less than or equal to a default resistance value, the control circuit periodically disables the power transfer circuit and determines whether to shut down the energy storage device according to a voltage difference of the AC output voltage in the default period, and when the resistance value of the load is greater than the default resistance value, the energy storage device is shut down.

7. The energy storage device according to claim 1 , wherein when the difference is greater than or equal to a default difference, the control circuit periodically disables the power transfer circuit, obtains the second voltage difference value, and determines whether to shut down the energy storage device according to the difference between the first voltage difference value and the second voltage difference, and when the difference is less than the default difference, the energy storage device is shut down.

8. The energy storage device according to claim 1 , wherein the default phase is close to 0 or 180 degrees.

9. A method of an energy storage device for supplying power, wherein the energy storage device comprises a battery module and a power transfer circuit, the power transfer circuit transfers a first DC voltage provided by the battery module into an AC output voltage to provide the AC output voltage to an output end of the power transfer circuit for providing power to a load, the energy storage device further comprises a switch circuit coupled between the output end of the power transfer circuit and the load, and the method of the energy storage device for supplying power comprises:
sensing the AC output voltage generated by the power transfer circuit;
controlling the switch circuit to enter an off-state during a first detection period;
during the first detection period, when the AC output voltage is at the default phase, disabling the power transfer circuit in the default period to obtain a first voltage difference value of the AC output voltage during the default period;
controlling the switch circuit to enter an on-state during a second detection period;
during the second detection period, when the AC output voltage is at the default phase, disabling the power transfer circuit in the default period to obtain a second voltage difference value of the AC output voltage during the default period; and
determining whether to shut down the energy storage device according to a difference between the first voltage difference value and the second voltage difference value.

10. The method of the energy storage device for supplying power according to claim 9 , the power transfer circuit comprises an output capacitor coupled to the output end of the power transfer circuit, wherein the AC output voltage is generated on the output capacitor.

11. The method of the energy storage device for supplying power according to claim 10 , the power transfer circuit comprises a DC/DC converter and a DC/AC inverter, the DC/AC inverter comprises the output capacitor, and the method of the energy storage device for supplying power comprises:
controlling the DC/DC converter to transfer the first DC voltage into a second DC voltage; and
controlling the DC/AC inverter to transfer the second DC voltage into the AC output voltage.

12. The method of the energy storage device for supplying power according to claim 11 , comprising:
turning off a plurality of voltage conversion switches comprised in the DC/AC inverter during the default period to disable the power transfer circuit.

13. The method of the energy storage device for supplying power according to claim 9 , comprising:
determining a resistance value of the load according to a voltage difference of the AC output voltage; and
determining whether to shut down the energy storage device according to the resistance value of the load.

14. The method of the energy storage device for supplying power according to claim 13 , comprising:
periodically disabling the power transfer circuit and determining whether to shut down the energy storage device according to a voltage difference of the AC output voltage in the default period when the resistance value of the load is less than or equal to a default resistance value; and
shutting down the energy storage device when the resistance value of the load is greater than the default resistance value.

15. The method of the energy storage device for supplying power according to claim 9 , comprising:
periodically disabling the power transfer circuit and obtaining the second voltage difference value when the difference is greater than or equal to a default difference, and determining whether to shut down the energy storage device according to the difference between the first voltage difference value and the second voltage difference value; and
shutting down the energy storage device when the difference is less than the default difference.

16. The method of the energy storage

Assignees

• Merry Electronics Shenzhen Co Ltd

Inventors

• Liu Yung-Hsiang
• Liang wei-kang
• Wang yu-kai

Classifications

• H02J7/96

  in response to battery voltage · CPC title

• H02J7/80

  including monitoring or indicating arrangements · CPC title

• H02J7/855 Primary

  with circuits adapted for supplying loads from the battery · CPC title

• H02J7/94

  in response to battery current · CPC title

• H02J7/663

  using battery or load disconnect circuits (H02J9/002 takes precedence) · CPC title