公开(公告)号：US20240106238A1

公开(公告)日：2024-03-28

申请号：US18519923

申请日：2023-11-27

Applicant: HUAWEI DIGITAL POWER TECHNOLOGIES CO., LTD.

Inventor： Mingxuan DONG ,  Kai XIN

IPC: H02J3/32 ,  H02J3/24 ,  H02J3/34 ,  H02J7/00

CPC classification number: H02J3/32 ,  H02J3/241 ,  H02J3/34 ,  H02J7/00041 ,  H02J7/0048

Abstract: This application discloses examples of an energy storage system, a power conversion system, and a method for optimizing primary frequency modulation. In one example, when the power conversion system determines that a state of charge (SoC) value of a target energy storage battery does not meet a target SoC value and determines that a present frequency of a power grid falls within a frequency modulation constant band, the power conversion system determines, based on a preset mapping relationship between a SoC value and an active power, a first specified active power value corresponding to the SoC value of the target energy storage battery, and controls, based on the first specified active power value, the target energy storage battery to be charged or discharged, so that the SoC value of the target energy storage battery can reach the target SoC value.

公开(公告)号：US20250062619A1

公开(公告)日：2025-02-20

申请号：US18796732

申请日：2024-08-07

Applicant: Huawei Digital Power Technologies Co., Ltd.

Inventor： Meiqing ZHANG ,  Mingxuan DONG ,  Ce FANG ,  Kai XIN

IPC: H02J3/32 ,  H02J3/38 ,  H02J7/00 ,  H02J7/06

Abstract: The embodiments include a power converter including a DC/AC conversion unit. A direct current bus is connected to the DC/AC conversion unit and a direct current source. The DC/AC conversion unit is further connected to a power grid. When a direct current bus voltage is less than or equal to a first voltage threshold, the power converter may switch to a current source mode to output first output power to the power grid, where the first output power is equal to an output power limit of the direct current source. Then, if a fluctuation amplitude of the direct current bus voltage is less than or equal to a first fluctuation threshold, the power converter may resume outputting second output power to the power grid in a voltage source mode, so that the second output power is less than or equal to the output power limit of the direct current source.

公开(公告)号：US20240022082A1

公开(公告)日：2024-01-18

申请号：US18471694

申请日：2023-09-21

Applicant: HUAWEI DIGITAL POWER TECHNOLOGIES CO., LTD.

Inventor： Mingxuan DONG ,  Kai XIN

IPC: H02J3/38 ,  H02J3/00 ,  G05B17/02

CPC classification number: H02J3/388 ,  H02J3/001 ,  G05B17/02

Abstract: This application provides an energy storage system, including a controller, an inverter, an on-grid/off-grid mode switch, and a load. The inverter is configured to: in response to determining that, the energy storage system is in an islanding state, freeze an output frequency of the inverter based on a preset frequency, and control an output current of the inverter based on an association relationship that an output voltage of the inverter is negatively correlated with apparent power of the inverter. The controller is configured to send a disconnection instruction to the on-grid/off-grid mode switch. The controller is further configured to send a switching instruction to the inverter in response to receiving a disconnection complete message from the on-grid/off-grid mode switch. The inverter is further configured to switch to a voltage source mode in response to determining that the output voltage of the inverter meets the preset range of the rated voltage.

公开(公告)号：US20230031139A1

公开(公告)日：2023-02-02

申请号：US17875923

申请日：2022-07-28

Applicant: Huawei Digital Power Technologies Co., Ltd.

Inventor： Mingxuan DONG ,  Yunfeng LIU ,  Kai XIN

IPC: H02J3/32 ,  H02J3/38 ,  H02J7/00

Abstract: An energy storage system includes at least two power conversion systems PCSs, output terminals of the at least two PCSs are connected in parallel to connect to an alternating current power grid, and input terminals of the at least two PCSs are connected to an energy storage power supply. The first PCS is any one of the at least two PCSs. The voltage detection circuit detects a power grid voltage at a parallel connection point of the output terminals of the at least two PCSs. When determining, based on the power grid voltage at the parallel connection point, that islanding occurs in the alternating current power grid, the controller adjusts an angle of an output voltage of the first PCS to a reference angle, so that angles of output voltages of the at least two PCSs are the same.