US-12627152-B2 - Power system and power control method

Abstract

A power system includes a power conversion circuit, a DC converter and an inverter. The power conversion circuit is coupled to a AC supply line and a DC supply line to convert voltage between the AC supply line and the DC supply line. The DC converter is coupled to the DC supply line and a charging device. The inverter is coupled to the AC supply line and the charging device. When the charging device provides a supply power to the inverter, the inverter is configured to convert the supply power into a recovered power and transmit the recovered power to the power conversion circuit.

Inventors

• Yi-Kuan KE
• Hong-Jhih LIU
• MENG-JIA LIU
• Chia-Ching Lin

Assignees

• DELTA ELECTRONICS, INC.

Dates

Publication Date

20260512

Application Date

20231113

Priority Date

20230808

Claims (17)

1. 1 . A power system, comprising: a power conversion circuit coupled to an AC supply line and a DC supply line, and configured to convert a voltage between the AC supply line and the DC supply line; at least one DC converter coupled to the power conversion circuit through the DC supply line, and coupled to at least one charging device, wherein the at least one DC converter is configured to output a working voltage that matches a working voltage of the at least one charging device; at least one inverter coupled to the AC supply line and the at least one charging device, wherein when the at least one charging device provides a supply power to the at least one inverter, the at least one inverter is configured to convert the supply power into a recovered power and transmit the recovered power to the power conversion circuit; and a controller coupled to the at least one DC converter and the at least one inverter, and configured to transmit a charging power data to the at least one charging device, wherein the charging power data is configured to limit a charging power of the at least one charging device.
2. 2 . The power system of claim 1 , wherein the controller is coupled to the power conversion circuit and the at least one charging device, and is configured to receive a charging test data from the at least one inverter or the at least one charging device.
3. 3 . The power system of claim 2 , wherein the charging test data comprises a voltage change or a current change of the at least one inverter or the at least one charging device during a detection period.
4. 4 . The power system of claim 2 , wherein the controller is configured to turn on a switch on the AC supply line, so that the power conversion circuit receives a mains voltage through the AC supply line, and establishes a DC voltage on the DC supply line according to the mains voltage.
5. 5 . The power system of claim 2 , further comprises: an uninterruptible power supply device coupled to the AC supply line and the controller, wherein the controller is driven by the uninterruptible power supply device; and an energy storage device coupled to the DC supply line and the controller, wherein the controller is configured to establish a DC voltage on the DC supply line through the energy storage device to drive the power conversion circuit; wherein after the DC voltage is established on the DC supply line, the power conversion circuit is configured to establish an AC voltage on the AC supply line according to the DC voltage.
6. 6 . The power system of claim 5 , wherein the controller is further configured to determine whether a mains voltage on the AC supply line is stable, and when the mains voltage is not stable, the controller is configured to turn off a switch between the AC supply line and a mains power grid.
7. 7 . The power system of claim 1 , wherein the power system comprises a plurality of DC converters, one of the plurality of DC converters is coupled to a renewable energy device to receive a charging power from the renewable energy device.
8. 8 . A power control method, comprising: stabilizing, by a power conversion circuit, a DC voltage of a DC supply line according to an AC voltage of an AC supply line, and transmitting the DC voltage to at least one DC converter, wherein the at least one DC converter is configured to convert the DC voltage and provide a working voltage that matches a working voltage of at least one charging device to the at least one charging device; transmit, by a controller, a charging power data to the at least one charging device, wherein the charging power data is configured to limit a charging power of the at least one charging device; connecting at least one inverter to the at least one charging device to receive a supply power outputted by the at least one charging device; and converting, by the at least one inverter, the supply power to a recovered power, and transmitting the recovered power to the power conversion circuit through the AC supply line.
9. 9 . The power control method of claim 8 , further comprising: receiving, by the controller, a charging test data from the at least one inverter or the at least one charging device, wherein the charging test data comprises a voltage change or a current change of the at least one inverter or the at least one charging device during a detection period.
10. 10 . The power control method of claim 9 , further comprising: turning on a switch of the AC supply line, so that the power conversion circuit receive a mains voltage through the AC supply line; and establishing the DC voltage on the DC supply line according to the mains voltage.
11. 11 . The power control method of claim 9 , further comprising: driving the controller by an uninterruptible power supply device; using, by the controller, a power of an energy storage device to establish the DC voltage on the DC supply line to drive the power conversion circuit; and establishing, by the power conversion circuit, the AC voltage on the AC supply line according to the DC voltage.
12. 12 . The power control method of claim 9 , further comprising: determining, by the controller, whether a mains voltage on the AC supply line is stable; and when the mains voltage is not stable, turning off a switch between the AC supply line and a mains power grid.
13. 13 . The power control method of claim 8 , wherein connecting the at least one inverter to the at least one charging device to receive the supply power outputted by the at least one charging device comprises: after the DC voltage of the DC supply line and the AC voltage of the AC supply line are both stable, turning on a switch on the AC supply line to connect the at least one inverter between the at least one charging device and the AC supply line.
14. 14 . A power system, comprising: a power conversion circuit coupled to an AC supply line and a DC supply line, and configured to convert a voltage between the AC supply line and the DC supply line; a plurality of DC converters coupled to the power conversion circuit through the DC supply line, and coupled to at least one charging device, wherein the plurality of DC converters is configured to output a working voltage that matches a working voltage of the at least one charging device; a controller coupled between the power conversion circuit and the plurality of DC converters, wherein when an AC voltage is established on the AC supply line, the controller is configured to control the power conversion circuit to stabilize a DC voltage on the DC supply line according to the AC voltage, so as to output or receive power by the plurality of DC converters; wherein the controller is further configured to transmit a charging power data to the at least one charging device, wherein the charging power data is configured to limit a charging power of the at least one charging device; an uninterruptible power supply device coupled to the AC supply line and the controller, wherein the controller is driven by the uninterruptible power supply device; and an energy storage device coupled to the DC supply line and the controller, wherein the controller is configured to establish the DC voltage on the DC supply line through the energy storage device to drive the power conversion circuit; wherein after the DC voltage is established on the DC supply line, the power conversion circuit is configured to establish an AC voltage on the AC supply line according to the DC voltage.
15. 15 . The power system of claim 14 , wherein the power system further comprises: an inverter coupled to the AC supply line and the at least one charging device, wherein when the at least one charging device provides a supply power to the inverter, the inverter is configured to convert the supply power into a recovered power and transmit the recovered power to the power conversion circuit.
16. 16 . The power system of claim 15 , wherein the controller is configured to receive a charging test data from the inverter or the at least one charging device, and the charging test data comprises a voltage change or a current change of the inverter or the at least one charging device during a detection period.
17. 17 . The power system of claim 14 , wherein the controller is configured to turn on a switch on the AC supply line, so that the power conversion circuit receives a mains voltage through the AC supply line, and establishes the DC voltage on the DC supply line according to the mains voltage.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to China Application Serial Number 202310990882.X, filed Aug. 8, 2023, which is herein incorporated by reference in its entirety. BACKGROUND Technical Field The present disclosure relates to a power management technology, specifically a power system and power control method. Description of Related Art Electrical energy is generated from power stations, converted and supplied to industrial/commercial and household users by a mains power grid. However, mains power lines may cause unstable power supply due to unpredictable variables. For users with large power demand or extremely high demand for power supply stability, in order to improve the stability of power consumption, auxiliary microgrids can be established outside the mains grid to optimize or manage power. SUMMARY One aspect of the present disclosure is a power system, comprising a power conversion circuit, at least one DC converter and at least one inverter. The power conversion circuit is coupled to an AC supply line and a DC supply line, and is configured to convert a voltage between the AC supply line and the DC supply line. The at least one DC converter is coupled to the DC supply line and at least one charging device. The at least one inverter is coupled to the AC supply line and the at least one charging device. When the at least one charging device provides a supply power to the at least one inverter, the at least one inverter is configured to convert the supply power into a recovered power and transmit the recovered power to the power conversion circuit. Another aspect of the present disclosure is a power control method, comprising: stabilizing, by a power conversion circuit, a DC voltage of a DC supply line according to an AC voltage of an AC supply line, and transmitting the DC voltage to at least one DC converter, wherein the at least one DC converter is configured to provide the DC voltage to at least one charging device; connecting at least one inverter to the at least one charging device to receive a supply power outputted by the at least one charging device; and converting, by the at least one inverter, the supply power to a recovered power, and transmitting the recovered power to the power conversion circuit through the AC supply line. Another aspect of the present disclosure is a power system, comprising a power conversion circuit, a plurality of DC converters and a controller. The power conversion circuit is coupled to an AC supply line and a DC supply line, and is configured to convert a voltage between the AC supply line and the DC supply line. The plurality of DC converters is coupled to the power conversion circuit through the DC supply line. The controller is coupled between the power conversion circuit and the plurality of DC converters. When an AC voltage is established on the AC supply line, the controller is configured to control the power conversion circuit to stabilize a DC voltage on the DC supply line according to the AC voltage, so as to output or receive power by the plurality of DC converters. The present disclosure uses a DC coupling architecture to establish a power grid (microgrid), allowing the power conversion circuit to control power more stably. In addition, using a power recovery path formed by the inverter, the power system can simulate and detect load and operating conditions in a low-consumption state. It is to be understood that both the foregoing general description and the following detailed description are by examples, and are intended to provide further explanation of the disclosure as claimed. BRIEF DESCRIPTION OF THE DRAWINGS The present disclosure can be more fully understood by reading the following detailed description of the embodiment, with reference made to the accompanying drawings as follows: FIG. 1 is a schematic diagram of a power system in some embodiments of the present disclosure. FIG. 2 is a schematic diagram of a power system in some embodiments of the present disclosure. FIG. 3 is a schematic diagram of a power system in some embodiments of the present disclosure. FIG. 4 is a flowchart illustrating a power control method in some embodiments of the present disclosure. FIG. 5 is a flowchart illustrating a power control method in some embodiments of the present disclosure. DETAILED DESCRIPTION For the embodiment below is described in detail with the accompanying drawings, embodiments are not provided to limit the scope of the present disclosure. Moreover, the operation of the described structure is not for limiting the order of implementation. Any device with equivalent functions that is produced from a structure formed by a recombination of elements is all covered by the scope of the present disclosure. Drawings are for the purpose of illustration only, and not plotted in accordance with the original size. It will be understood that when an element is referred to as being “connected to” or “coupled to”, it can be di