公开(公告)号：US20190178923A1

公开(公告)日：2019-06-13

申请号：US16278224

申请日：2019-02-18

Applicant: Huawei Technologies Co., Ltd.

Inventor： Zhangping Shao ,  Kai Xin ,  Congyuan Wang

IPC: G01R23/15 ,  G01R31/02 ,  H02J3/38

Abstract: An islanding detection method and apparatus for an inverter, and a power supply system to resolve a problem that an existing voltage total harmonic distortion (THD)-based islanding detection method has low islanding detection reliability due to existence of a relatively large detection dead zone. According to this detection method, the voltage total harmonic distortion changes more significantly before and after the islanding effect of the inverter occurs in order to reduce an islanding detection dead zone and improve islanding detection reliability.

公开(公告)号：US11336094B2

公开(公告)日：2022-05-17

申请号：US17081076

申请日：2020-10-27

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Rongliang Shi ,  Zhangping Shao ,  Kai Xin

IPC: H02J3/01 ,  H02J3/38 ,  H02M1/12 ,  H02M1/44 ,  H02M7/539

Abstract: An inverter includes an inverter circuit; an alternating current filter, where an input port of the alternating current filter is connected to an output port of the inverter circuit; an alternating current electromagnetic interference (EMI) filter; and a first alternating current switch, connected between an output port of the alternating current filter and an input port of the alternating current EMI filter. The first split capacitor is disposed between the first alternating current switch and the input port of the alternating current EMI filter; and when the first alternating current switch is turned off, the first split capacitor is disconnected from the output port of the alternating current filter, and the first split capacitor is connected to a circuit in which an alternating current system connected to the output port of the alternating current EMI filter is located, to suppress harmonic distortion of the alternating current system.