公开(公告)号：US20230155386A1

公开(公告)日：2023-05-18

申请号：US18156672

申请日：2023-01-19

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Mingquan ZHAO ,  Zhangping SHAO ,  Haibin GUO

IPC: H02J3/36 ,  H02J3/12

CPC classification number: H02J3/36 ,  H02J3/12

Abstract: Embodiments of this application provide a direct current bus voltage control method and apparatus, and a power system, and relate to the field of electric power technologies, to quickly identify a voltage between an inverter circuit and an alternating current grid, so as to timely control a voltage of a direct current bus, thereby improving stability of the power system. The method includes: obtaining an electrical parameter between the conversion circuit and the direct current bus; generating a predicted voltage between the inverter circuit and the alternating current grid based on the electrical parameter and a voltage prediction model; and controlling a voltage between the conversion circuit and the direct current bus based on the predicted voltage.

公开(公告)号：US20190280484A1

公开(公告)日：2019-09-12

申请号：US16420496

申请日：2019-05-23

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Zhangping SHAO ,  Kai XIN ,  Haibin GUO

IPC: H02J3/38 ,  H02M7/5387

Abstract: An inverter anti-islanding control system includes a phase-shift loop (10) and a drive circuit (20). The phase-shift loop (10) includes a first input end (11), a second input end (12), a third input end (13), a fourth input end (14), a first output end (15), and a second output end (16). The drive circuit (20) includes a first input end (21), a second input end (22), a third input end (23), and an output end (24). The first output end (15) of the phase-shift loop (10) is connected to the first input end (21) of the drive circuit (20), and the second output end (16) of the phase-shift loop (10) is connected to the second input end (22) of the drive circuit (20). In the inverter anti-islanding control system, when an inverter is in an island state, a frequency of an inverter alternating current end voltage is deviated to a second frequency by using the phase-shift loop (10), so that the second frequency triggers frequency protection to disconnect the inverter from an electrical network, to be specific, the inverter is out of the island state.

公开(公告)号：US20190280609A1

公开(公告)日：2019-09-12

申请号：US16426171

申请日：2019-05-30

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Fangcheng LIU ,  Kai XIN ,  Haibin GUO

IPC: H02M5/458

Abstract: A pulse width modulation method, a pulse width modulation system, and a controller are provided, which change a change rate of a common-mode component of a three-phase converter upon a change of a converter modulation degree, thereby improving stability and harmonic characteristics of the three-phase converter and implementing flexible adaptive adjustment. An example pulse width modulation method includes: obtaining initial three-phase modulation waves and a converter modulation degree; calculating a common-mode-component change-rate adjustment coefficient based on preset modulation parameters and the converter modulation degree; selecting a modulation wave having a minimum absolute value from the modulation wave set as a common-mode modulation wave; and performing waveform superposition on the initial three-phase modulation waves and the common-mode modulation wave to obtain output three-phase modulation waves.

公开(公告)号：US20180166883A1

公开(公告)日：2018-06-14

申请号：US15893125

申请日：2018-02-09

Applicant: Huawei Technologies Co., Ltd.

Inventor： Kai XIN ,  Haibin GUO ,  Yongbing GAO

IPC: H02J3/38

CPC classification number: H02J3/385 ,  H02J3/38 ,  H02J3/383 ,  H02J2003/001 ,  H02M7/5395 ,  H02S40/32 ,  Y02E10/563 ,  Y02E10/58

Abstract: The present application provides a low voltage ride-through control system for a multi-inverter grid-connected power converter, including: a photovoltaic array and an inverter. The inverter includes a DC/DC conversion unit and a DC/AC inversion unit connected to an output end of the DC/DC conversion unit, an input end of the DC/DC conversion unit is connected to an output end of the photovoltaic array, and the inverter is connected to a power grid at a grid-connected point. The inverter further includes a low voltage ride-through detection unit and a low voltage ride-through control unit. The low voltage ride-through detection unit is configured to determine whether to trigger low voltage ride-through. The low voltage ride-through control unit is configured to lower an input voltage of the DC/DC conversion unit when it is determined to trigger the low voltage ride-through, to lower an output voltage of the photovoltaic array.