公开(公告)号：EP3681007A1

公开(公告)日：2020-07-15

申请号：EP17926771.1

申请日：2017-09-28

Applicant: Huawei Technologies Co., Ltd.

Inventor： YUAN, Hongwen ,  XU, Fuqiang ,  LIU, Fangcheng

IPC: H02J3/38 ,  H02J3/40 ,  H02M7/48 ,  H02M7/493 ,  H02M7/5395 ,  H02M1/00

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 θ 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, when it is detected that the phase of the alternating current voltage has reached a phase threshold (S102), where the phase threshold is a start phase of the preset phase threshold interval; calculating a period of a preset carrier wave based on a preset carrier wave ratio and the time period (S 103); generating the preset carrier wave based on the period of the preset carrier wave (S104); and generating a PWM control signal of the inverter based on a PWM modulation signal and the preset carrier wave (S105).

公开(公告)号：EP3764504A1

公开(公告)日：2021-01-13

申请号：EP19819626.3

申请日：2019-02-03

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： YU, Xinyu ,  XIN, Kai ,  LIU, Fangcheng

IPC: H02J3/38

Abstract: This application provides a control method and a controller for a string inverter, an inverter, and an inverter system. The method includes: in an 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 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 before IV curve scanning, and 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, of photovoltaic strings connected to all IV curve scanning DC-DC circuits. The inverter circuit is controlled to maintain a constant output power and a constant bus voltage, with no power fluctuation, and each non-IV curve scanning DC-DC circuit continues to output a power. In this way, photovoltaic energy is effectively utilized, and a huge energy yield loss is avoided.

公开(公告)号：EP3637607A1

公开(公告)日：2020-04-15

申请号：EP17910657.0

申请日：2017-05-25

Applicant: Huawei Technologies Co., Ltd.

Inventor： LIU, Fangcheng ,  WANG, Xiongfei ,  XIN, Kai

IPC: H02M7/23

Abstract: This application discloses an apparatus, an inverter system, and a method for synchronizing carriers. The apparatus includes a modulation unit, a current processing unit, and a control unit. The control unit can adjust, based on a change trend between an amplitude of a first harmonic current and an amplitude of a second harmonic current and a change trend between a phase of a first carrier and a phase of a second carrier, a phase of an input carrier input into the modulation unit, to decrease an amplitude of a harmonic current output by an inverter and improve stability of a distributed power supply system. Further, a prior-art problem that impact of a harmonic current on a power supply system cannot be reduced by synchronizing carriers in a process of synchronizing carriers based on a zero sequence current is avoided, thereby improving the stability of the distributed system.

公开(公告)号：EP3301777B1

公开(公告)日：2020-02-26

申请号：EP16817104.9

申请日：2016-06-01

Applicant: Huawei Technologies Co., Ltd.

Inventor： LIU, Fangcheng ,  XIN, Kai

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

公开(公告)号：EP3537589A1

公开(公告)日：2019-09-11

申请号：EP17875630.0

申请日：2017-04-24

Applicant: Huawei Technologies Co., Ltd.

Inventor： LIU, Fangcheng ,  XIN, Kai ,  GUO, Haibin

IPC: H02M7/537 ,  H02M1/12

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. The pulse width modulation method includes: obtaining initial three-phase modulation waves and a converter modulation degree (601); calculating a common-mode-component change-rate adjustment coefficient based on preset modulation parameters and the converter modulation degree; calculating a modulation wave set corresponding to the initial three-phase modulation waves based on a preset maximum modulation-wave amplitude-limiting value, a preset minimum modulation-wave amplitude-limiting value, the initial three-phase modulation waves, and the common-mode-component change-rate adjustment coefficient, and selecting a modulation wave having a minimum absolute value from the modulation wave set as a common-mode modulation wave (603); 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：EP3514939A1

公开(公告)日：2019-07-24

申请号：EP16917353.1

申请日：2016-09-30

Applicant: Huawei Technologies Co., Ltd.

Inventor： LIU, Fangcheng ,  XIN, Kai ,  GUO, Haibin

IPC: H02M7/487

Abstract: A three-phase converter is provided, and is configured to be connected 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 connected to the switching network, a sampling unit connected to the three-phase filter, a control unit connected to the three-phase sampling unit, an active damping unit connected to both the control unit and the sampling unit, and a modulation unit connected between the active damping unit and the switching network, where the sampling unit is configured to: obtain three-phase currents in the three-phase filter, and send the three-phase currents to the active damping unit; the active damping unit 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 unit; and the modulation unit is configured to modulate the new three-phase modulated waves into drive signals of the switching network, to drive the switching network to work.

公开(公告)号：EP3301777A1

公开(公告)日：2018-04-04

申请号：EP16817104.9

申请日：2016-06-01

Applicant: Huawei Technologies Co., Ltd.

Inventor： LIU, Fangcheng ,  XIN, Kai

IPC: H02J3/38

CPC classification number: G01R31/086 ,  G01R27/16 ,  G01R27/26 ,  G01R31/44 ,  H02H1/0007 ,  H02H1/0092 ,  H02H7/1227 ,  H02J3/38 ,  H02M1/084 ,  H02M7/42 ,  H02M7/53875 ,  H02M2001/0009

Abstract: The present invention relates to the field of inverters, and specifically, to a method for detecting grid connection stability of an inverter and an inverter. The method includes: injecting, by an inverter, a first-sequence disturbance current into the power grid, and while the first-sequence disturbance current is injected, 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; injecting a second-sequence disturbance current into the power grid, and while the second-sequence disturbance current is injected into the power grid, 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. According to the method, impact of a power grid on an inverter can be determined when measurement costs are reduced.

Abstract translation: 检测逆变器和逆变器的并网稳定性的方法技术领域本发明涉及逆变器领域，具体涉及检测逆变器和逆变器的并网稳定性的方法。 该方法包括：逆变器向电网注入第一序列扰动电流，在注入第一序列扰动电流的同时，检测交流端口的线电压和电流，得到第一组 线电压值和第一组电流值; 向电网中注入第二序列干扰电流，并且在将第二序列干扰电流注入到电网中时，检测交流端口的线电压和电流以获得第二组线电压值，并且a 第二组当前值; 根据第一组线电压值，第一组电流值，第二组线电压值和第二组电流值获得电网的等效阻抗矩阵; 逆变器根据等效导纳矩阵和等效阻抗矩阵确定是否满足逆变器的稳定性要求。 根据该方法，当测量成本降低时，可以确定电网对逆变器的影响。

公开(公告)号：EP4148942A1

公开(公告)日：2023-03-15

申请号：EP22185955.6

申请日：2017-09-28

Applicant: Huawei Technologies Co., Ltd.

Inventor： YUAN, Hongwen ,  XU, Fuqiang ,  LIU, Fangcheng

IPC: H02J3/38 ,  H02J3/40 ,  H02M7/48 ,  H02M7/493 ,  H02M7/5395 ,  H02M1/00

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 0 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, when it is detected that the phase of the alternating current voltage has reached a phase threshold (S102), where the phase threshold is a start phase of the preset phase threshold interval; calculating a period of a preset carrier wave based on a preset carrier wave ratio and the time period (S103); generating the preset carrier wave based on the period of the preset carrier wave (S104); and generating a PWM control signal of the inverter based on a PWM modulation signal and the preset carrier wave (S105).

公开(公告)号：EP3506474A1

公开(公告)日：2019-07-03

申请号：EP18214165.5

申请日：2018-12-19

Applicant: Huawei Technologies Co., Ltd.

Inventor： LIU, Fangcheng ,  XIN, Kai ,  LIU, Yunfeng

IPC: H02M1/12 ,  H02M7/06 ,  H03K17/567

Abstract: Embodiments of this application disclose a single-phase converter control method and apparatus. The method 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. According to the embodiments of this application, a system neutral-point potential balancing capability, a system response speed, and system reliability can be improved.

公开(公告)号：EP3793091A1

公开(公告)日：2021-03-17

申请号：EP19812631.0

申请日：2019-03-30

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： YANG, Dongsheng ,  LIU, Fangcheng ,  WANG, Xiongfei

IPC: H03L7/08

Abstract: Embodiments of this application provide a phase-locking apparatus and a phase-locking method. The phase-locking apparatus includes an amplitude adjustment unit, an amplitude and phase detector connected to the amplitude adjustment unit, a first loop filter connected to the amplitude and phase detector, a second loop filter connected to the amplitude and phase detector, a first oscillator connected to the first loop filter, and a second oscillator connected to the second loop filter. The amplitude adjustment unit, the amplitude and phase detector, the first loop filter, and the first oscillator form a loop; and the amplitude and phase detector, the second loop filter, and the second oscillator form another loop. According to the embodiments of this application, a dual-loop structure of the phase-locking apparatus can weaken frequency coupling between a positive-sequence component generated by the phase-locking apparatus and a negative-sequence component generated by the phase-locking apparatus.