公开(公告)号：US10345362B2

公开(公告)日：2019-07-09

申请号：US15855396

申请日：2017-12-27

Applicant: Huawei Technologies Co., Ltd.

Inventor： Fangcheng Liu ,  Kai Xin

IPC: G01R27/16 ,  G01R27/26 ,  G01R31/08 ,  G01R31/44 ,  H02M7/42 ,  H02M1/00 ,  H02H1/00 ,  H02J3/38 ,  H02H7/122 ,  H02M1/084 ,  H02M7/5387

Abstract: The present disclosure relates to the field of inverters, and to a method for detecting grid connection stability of an inverter and an inverter. The method includes: detecting a line voltage and a current of the alternating current port to obtain a first group of line voltage values and a first group of current values; detecting the line voltage and the current of the alternating current port to obtain a second group of line voltage values and a second group of current values; obtaining an equivalent impedance matrix of the power grid according to the first group of line voltage values, the first group of current values, the second group of line voltage values, and the second group of current values; and determining, by the inverter according to an equivalent admittance matrix and the equivalent impedance matrix, whether a stability requirement of the inverter is met.

公开(公告)号：US20190199235A1

公开(公告)日：2019-06-27

申请号：US16232741

申请日：2018-12-26

Applicant: Huawei Technologies Co., Ltd.

Inventor： Fangcheng Liu ,  Kai Xin ,  Yunfeng Liu

IPC: H02M7/487 ,  H02J3/38 ,  H02M7/5387

CPC classification number: H02M7/487 ,  H02J3/383 ,  H02M1/12 ,  H02M7/53871 ,  H02M7/5395 ,  H02M2001/123 ,  H03K17/567

Abstract: A single-phase converter control method and apparatus, includes calculating on a voltage corresponding to a first level output by a single-phase converter, a voltage corresponding to a second level output by the single-phase converter, and a voltage reference value about the voltage corresponding to the first level and the voltage corresponding to the second level to obtain a common-mode modulated-wave change rate of the single-phase converter, where the first level is a direct-current-side positive-bus level, and the second level is a direct-current-side negative-bus level, calculating on a first-phase initial modulated wave of the single-phase converter, a second-phase initial modulated wave of the single-phase converter, and the common-mode modulated-wave change rate to obtain a common-mode modulated wave of the single-phase converter, and calculating on the first-phase initial modulated wave, the second-phase initial modulated wave, and the common-mode modulated wave to obtain a pulse width modulated wave of the single-phase converter.

公开(公告)号：US11171489B2

公开(公告)日：2021-11-09

申请号：US17073864

申请日：2020-10-19

Applicant: Huawei Technologies Co., Ltd.

Inventor： Xinyu Yu ,  Kai Xin ,  Fangcheng Liu

IPC: H02J3/38

Abstract: A control method for a string inverter, comprising: in a current/voltage (IV) curve scanning process, controlling an output power of an inverter circuit to be a specified power reference value, and controlling an output voltage of each non-IV curve scanning direct current (DC) to DC (DC-DC) circuit to be a specified voltage reference value, where the specified power reference value is less than or equal to a sum of input powers of all non-IV curve scanning DC-DC circuits the before IV curve scanning process, and where the specified voltage reference value is greater than or equal to a preset percentage of a maximum value in open-circuit voltages, before the IV curve scanning process, of photovoltaic strings connected to all IV curve scanning DC-DC circuits.

公开(公告)号：US20210036520A1

公开(公告)日：2021-02-04

申请号：US17073864

申请日：2020-10-19

Applicant: Huawei Technologies Co., Ltd.

Inventor： Xinyu Yu ,  Kai Xin ,  Fangcheng Liu

IPC: H02J3/38

Abstract: A control method for a string inverter, comprising: in a current/voltage (IV) curve scanning process, controlling an output power of an inverter circuit to be a specified power reference value, and controlling an output voltage of each non-IV curve scanning direct current (DC) to DC (DC-DC) circuit to be a specified voltage reference value, where the specified power reference value is less than or equal to a sum of input powers of all non-IV curve scanning DC-DC circuits the before IV curve scanning process, and where the specified voltage reference value is greater than or equal to a preset percentage of a maximum value in open-circuit voltages, before the IV curve scanning process, of photovoltaic strings connected to all IV curve scanning DC-DC circuits.

公开(公告)号：US20200227919A1

公开(公告)日：2020-07-16

申请号：US16833969

申请日：2020-03-30

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Hongwen Yuan ,  Fuqiang Xu ,  Fangcheng Liu

IPC: H02J3/38 ,  H02M7/48 ,  H02M1/08

Abstract: A method for synchronizing PWM control signals of inverters, an inverter, and a power grid system are disclosed, so that PWM control signals of inverters connected to a power grid can be synchronized. A direct current voltage terminal of the inverter is connected to an external power supply, and an alternating current voltage terminal of the inverter is connected to an alternating current point of common coupling of a power grid, and the method includes: obtaining a phase of an alternating current voltage of the power grid (S101); determining a time period during which the phase of the alternating current voltage varies within a preset phase threshold interval; calculating a period of a preset carrier wave based on a preset carrier wave ratio and the time period (S103); and generating a PWM control signal of the inverter based on a PWM modulation signal and a preset carrier wave (S105).

公开(公告)号：US10666159B2

公开(公告)日：2020-05-26

申请号：US16232741

申请日：2018-12-26

Applicant: Huawei Technologies Co., Ltd.

Inventor： Fangcheng Liu ,  Kai Xin ,  Yunfeng Liu

IPC: H02M7/487 ,  H02M1/12 ,  H03K17/567 ,  H02M7/5395 ,  H02J3/38 ,  H02M7/5387

Abstract: A single-phase converter control method and apparatus, includes calculating on a voltage corresponding to a first level output by a single-phase converter, a voltage corresponding to a second level output by the single-phase converter, and a voltage reference value about the voltage corresponding to the first level and the voltage corresponding to the second level to obtain a common-mode modulated-wave change rate of the single-phase converter, where the first level is a direct-current-side positive-bus level, and the second level is a direct-current-side negative-bus level, calculating on a first-phase initial modulated wave of the single-phase converter, a second-phase initial modulated wave of the single-phase converter, and the common-mode modulated-wave change rate to obtain a common-mode modulated wave of the single-phase converter, and calculating on the first-phase initial modulated wave, the second-phase initial modulated wave, and the common-mode modulated wave to obtain a pulse width modulated wave of the single-phase converter.

公开(公告)号：US20190229646A1

公开(公告)日：2019-07-25

申请号：US16369828

申请日：2019-03-29

Applicant: Huawei Technologies Co., Ltd.

Inventor： Fangcheng Liu ,  Kai Xin ,  Haibin Guo

IPC: H02M7/5387 ,  H02S40/32 ,  H02P27/08 ,  H03H7/01 ,  H02M1/12 ,  H02J3/38

Abstract: A three-phase converter configured to be coupled between a direct current system and an alternating current system to perform interconversion between a direct current and an alternating current, where the three-phase converter includes a switching network, a three-phase filter coupled to the switching network, a sampling circuit coupled to the three-phase filter, a control circuit coupled to the three-phase sampling circuit, an active damping circuit coupled to the control circuit and the sampling circuit, and a modulation circuit coupled between the active damping circuit and the switching network, where the sampling circuit is configured to obtain three-phase currents in the three-phase filter, and send the three-phase currents to the active damping circuit, the active damping circuit is configured to obtain new three-phase modulated waves according to the three-phase currents, and transmit the new three-phase modulated waves to the modulation circuit.