公开(公告)号：US20220006298A1

公开(公告)日：2022-01-06

申请号：US17479820

申请日：2021-09-20

Applicant: Huawei Technologies Co., Ltd.

Inventor： Xinyu YU ,  Kai XIN ,  Junjie LI

IPC: H02J3/38 ,  H02J3/01 ,  H02J3/00

Abstract: An islanding detection method and apparatus, and a computer-readable storage medium. The detection method includes: determining a harmonic amplitude growth rate and a frequency growth rate of alternating current electricity output by an alternating current port of a grid-tied inverter; determining an islanding disturbance coefficient corresponding to the harmonic amplitude growth rate, where the harmonic amplitude growth rate and the islanding disturbance coefficient are in a monotonically increasing relationship; determining an islanding injection amount based on the frequency growth rate and the islanding disturbance coefficient corresponding to the harmonic amplitude growth rate; controlling, based on the islanding injection amount, the grid-tied inverter to output a reactive power or a reactive current over the alternating current port; and performing islanding detection based on a frequency of the alternating current electricity output by the alternating current port. With this detection method, whether islanding occurs can be accurately detected. When islanding does not occur, disturbance to a power grid is reduced, and grid connection stability is improved. When islanding occurs, it can be quickly detected, and a detection time is relatively short.

公开(公告)号：US20210058030A1

公开(公告)日：2021-02-25

申请号：US17035142

申请日：2020-09-28

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Fangcheng LIU ,  Kai XIN ,  Xinyu YU

IPC: H02S50/00 ,  H02S40/32

Abstract: One example method includes obtaining output powers at initial scanning points of photovoltaic strings in a first group and a second group. The output powers at the initial scan points of the photovoltaic strings in the first group can then be controlled to sequentially decrease, and the output powers at the initial scan points of the photovoltaic strings in the second group can then be controlled to sequentially increase. Scanning can then be performed in the initial scanning direction starting from output voltages corresponding to the output powers at the initial scan points of the first group. Scanning can then be performed in the initial scanning direction starting from output voltages corresponding to the output powers at the initial scan points of the second group, where output powers of the first group and the second group are kept to compensate each other during IV curve scanning.

公开(公告)号：US20220037890A1

公开(公告)日：2022-02-03

申请号：US17503016

申请日：2021-10-15

Applicant: Huawei Technologies Co., Ltd.

Inventor： Xinyu YU ,  Kai XIN

IPC: H02J3/46 ,  H02S40/32 ,  H02J3/38 ,  H02M7/539

Abstract: A photovoltaic inverter is provided, including an inverter circuit, a data sampling module, and a control module. The inverter circuit includes a switch component and an alternating current output terminal. The data sampling module is configured to collect, from the alternating current output terminal, an instantaneous current value at each sampling point moment in target sampling duration and an instantaneous value of each-phase current at a target moment. The control module is configured to: determine a valid current value of the target sampling duration based on the instantaneous current value at each sampling point moment, determine an upper switching frequency limit and a lower switching frequency limit of an Nth switching period based on the valid current value, and determine a target instantaneous current value IN based on the instantaneous value of each-phase current at the target moment.

公开(公告)号：US20210408968A1

公开(公告)日：2021-12-30

申请号：US17473534

申请日：2021-09-13

Applicant: Huawei Technologies Co., Ltd.

Inventor： Jianqiang WANG ,  Song WAN ,  Yanzhong ZHANG ,  Yongbing GAO ,  Xinyu YU

IPC: H02S50/15 ,  H02H7/20 ,  H02H1/00

Abstract: A fault detection apparatus includes an image capture module and a detection module, and the fault detection apparatus is configured to capturing an image of the photovoltaic module in a light emitting state, and performing fault detection on the photovoltaic module based on the image when a signal-to-noise ratio of the image is maximized, to identify a fault type of the photovoltaic module.