Huawei Digital Power Technologies Co., Ltd.

Huawei Technologies Co., Limited

Huawei Digital Technologies Co., Ltd.

Kai Xin

Xinyu Yu

Yunfeng Liu

Fangcheng Liu

Haibin Guo

Peng Dong

Zhangping Shao

Junjie Li

Mingxuan Dong

Yanzhong Zhang

Fei Xu

Jianqiang Wang

Fuqiang Xu

Rongliang Shi

Shuo Wang

Yongbing Gao

Zhiwu Xu

Song Wan

Mingquan Zhao

Congyuan Wang

Lei Shi

You Zhou

Li Hui Lu

Yan Chen

Wei Li

Xudong Wang

Lin Li

Xiaosheng Zeng

Xiaowen Dong

Yazhu Zhao

Xiongfei Wang

Shuchao Wang

Yuan Yao

Lin Ji

Wenchao Li

Zisen Qu

Meiqing Zhang

Jiuyang Zhou

Jiaguang Fu

A power supply system, an inverter, and a method for controlling positive and negative bus voltages of an inverter. The power supply system includes at least one group of inverters, each group of the at least one group of inverters includes a primary inverter and at least one secondary inverter corresponding to the primary inverter, an input end of the primary inverter is coupled to a direct current power supply corresponding to the primary inverter, an input end of the secondary inverter is coupled to a direct current power supply corresponding to the secondary inverter, and a three-phase output end of the primary inverter is coupled to a three-phase output end of the secondary inverter and then is connected to an alternating current power grid.

Power supply system, inverter, and method for controlling positive and negative bus voltages of inverter

The embodiments provide an RSCC and a control method thereof. The RSCC includes an input capacitor, an output capacitor, N parallel RSC branches, and a controller. The controller is configured to: determine an average value of characteristic currents of N resonance units; and reduce a duty cycle of a control signal of a charging switch in a first switch unit when determining that a characteristic current of a first resonance unit is greater than the average value, where a corresponding branch is in a charging stage when the charging switch is turned on; or reduce a duty cycle of a control signal of a discharging switch in a first switch unit when determining that a characteristic current of a first resonance unit is less than the average value, where a corresponding branch is in a discharging stage when the discharging switch is turned on.

Resonant switched capacitor converter and control method thereof

A power converter control method includes: determining a phase angle difference between a phase angle of a voltage output by the power converter and a phase angle of a power grid voltage; and if the phase angle difference is greater than or equal to a first angle threshold, setting a d-axis current reference value and a q-axis current reference value that are used to determine a modulation voltage of the power converter to preset fixed values; calculating a first modulation voltage of the power converter based on the d-axis current reference value, the q-axis current reference value, and a power grid current; calculating a compensation voltage of the power converter based on a preset virtual resistance parameter and the power grid current; and using a sum of the first modulation voltage and the compensation voltage as a total modulation voltage.

Power convertor control method, control apparatus, and computer storage medium

A converter circuit is configured to output a first reactive current to a power grid when a voltage value of an output port of the converter circuit decreases from a first working voltage value to a second working voltage value. The drive control circuit is configured to: in a process in which the converter circuit outputs the first reactive current to the power grid, when it is detected that the voltage value of the output port of the converter circuit increases to a third working voltage value and the third working voltage value is greater than or equal to a first recovery voltage value, control the converter circuit to output a second reactive current to the power grid, to recover the voltage value of the output port of the converter circuit to the first working voltage value.

Power supply system and current conversion method

The photovoltaic power generation system includes a controller and M groups of DC-DC circuits. Each group of DC-DC circuits include N DC-DC circuits, where M is a positive integer, and N is an integer greater than 1. An input end of each DC-DC circuit is connected to at least one photovoltaic unit, and each photovoltaic unit includes at least one photovoltaic module. The controller controls the N DC-DC circuits in each group of DC-DC circuits to sequentially start online IV curve scanning and controls a time interval at which two adjacent DC-DC circuits start online IV curve scanning to be less than duration of online IV curve scanning performed by one DC-DC circuit. The photovoltaic power generation system can reduce a fluctuation of a power output during online IV curve scanning, reduce duration of online IV curve scanning performed by the photovoltaic power generation system.

Photovoltaic power generation system, photovoltaic inverter, and IV curve scanning method

A voltage conversion unit includes a positive voltage conversion apparatus and a negative voltage conversion apparatus. The inverter unit includes a positive inverter and a negative inverter. A negative output end of the positive voltage conversion apparatus and a positive output end of the negative voltage conversion apparatus are connected to a first end of a neutral wire, and a negative input end of the positive inverter and a positive input end of the negative inverter are connected to a second end of the neutral wire. When the neutral wire current does not meet the preset current range, the controller control the positive voltage conversion apparatus and the negative voltage conversion apparatus to change output voltages when output power remains unchanged, so that the neutral wire current meets the preset current range.

Bipolar power supply system and control method

A power supply system and a grid connection control method. The power supply system includes a power supply, an inverter, a transformer, a power station collection module, and an inverter collection control circuit. The inverter collection control circuit is configured to obtain an amplitude value and a frequency of an output voltage of the inverter, obtain an inverter power adjustment signal based on the amplitude value and the frequency of the output voltage, and control, based on the power station power adjustment signal and the inverter power adjustment signal, the inverter to output a target output power. Additionally, an output power of the inverter may be adjusted by using the power station collection module and the inverter collection control circuit. A structure is simple, and a control method is simple. This improves control precision and adjustment efficiency, reduces control time, and reduces control costs.

Power supply system and grid connection control method

A three-level neutral point clamped inverter includes four switch units. When an average value of an output current of the three-level neutral point clamped inverter is greater than a first current threshold or less than a second current threshold, only one of the four switch units is controlled to perform a high-frequency operation, to reduce power consumption caused by a high-frequency operation. The average value of the output current is an average value of the output current of the three-level neutral point clamped inverter in a switching cycle. The first current threshold is a positive number, and the second current threshold is a negative number. Power consumption caused by the high-frequency operation of the switch unit in the inverter may be reduced, and electric energy conversion efficiency of the inverter may be improved. A time period in which two switch units perform complementary operations at high frequency is very small.

Photovoltaic system, inverter, and control method

A photovoltaic cell detection method includes determining a first output power working at a first voltage and a second output power working at a second voltage, where a difference between the first output power and the second output power is less than a power difference threshold, and where both the first output power and the second output power are greater than 0; controlling the photovoltaic cell to work at the first voltage, and obtaining first infrared image information of the photovoltaic cell; and controlling the photovoltaic cell to work at the second voltage, and obtaining second infrared image information of the photovoltaic cell, where both the first infrared image information and the second infrared image information are used to jointly detect whether the photovoltaic cell is faulty.

Photovoltaic cell detection method, apparatus, and system, medium, and chip

This application provides an inverter, a power grid power supply system, and a method for controlling an excitation inrush current. The controller adjusts the output voltage of the conversion circuit based on a first phase that is of the output voltage of the conversion circuit and that is during reduction of the output voltage, the magnetic flux of the iron core in the transformer, an output voltage that is of the conversion circuit and that is after the output voltage is reduced, and the target voltage value, so as to increase the output voltage of the conversion circuit and keep the magnetic flux of the iron core less than the saturation magnetic flux.

Inverter, power grid power supply system, and method for controlling excitation inrush current

A photovoltaic system includes a controller and two groups of inverters. The two groups of inverters include a positive inverter group and a negative inverter group. The positive inverter group includes at least two inverters: a first inverter and a third inverter. The negative inverter group includes at least two inverters: a second inverter and a fourth inverter. Alternating current output ends of the first inverter and the third inverter are connected in parallel. Direct current input ends of the first inverter and the second inverter are connected in series. Alternating current output ends of the second inverter and the fourth inverter are connected in parallel. Direct current input ends of the third inverter and the fourth inverter are connected in series.

Photovoltaic system, protection method, and inverter system

This application discloses a photovoltaic system and a carrier wave signal synchronization method. The photovoltaic system includes a plurality of inverters and a controller. Each inverter in the photovoltaic system inverts a direct current into an alternating current based on a received carrier wave signal, and transmits the alternating current to a power grid. The controller obtains first output currents of the plurality of inverters in an adjustment period, so that the controller can obtain first output current valid values of the plurality of inverters based on the first output currents of the plurality of inverters.

Photovoltaic system and carrier wave signal synchronization method

This application discloses examples of an energy storage system, a power conversion system, and a method for optimizing primary frequency modulation. In one example, when the power conversion system determines that a state of charge (SoC) value of a target energy storage battery does not meet a target SoC value and determines that a present frequency of a power grid falls within a frequency modulation constant band, the power conversion system determines, based on a preset mapping relationship between a SoC value and an active power, a first specified active power value corresponding to the SoC value of the target energy storage battery, and controls, based on the first specified active power value, the target energy storage battery to be charged or discharged, so that the SoC value of the target energy storage battery can reach the target SoC value.

Energy storage system, power conversion system, and method for optimizing primary frequency modulation

A method and apparatus for suppressing cross current including: obtaining a common-mode current and a common-mode injection voltage of each inverter in an inverter parallel system; determining a virtual damping voltage of each inverter based on the common-mode current of each inverter and a preset common-mode damping factor, where if a direction in which a current flows out of the inverter is a positive direction, the preset common-mode damping factor is a negative value, or if a direction in which a current flows into the inverter is a positive direction, the preset common-mode damping factor is a positive value; superimposing the virtual damping voltage on the common-mode injection voltage of each inverter, to obtain a target common-mode voltage of each inverter; and controlling operation of each inverter based on the target common-mode voltage of each inverter and a differential mode voltage of each inverter.

Method and apparatus for suppressing cross current in inverter parallel system

A power line communication (PLC) system includes a PLC signal transmitting end, a PLC signal receiving end, and a power electronic apparatus. The PLC signal transmitting end is connected to the PLC signal receiving end through a power line, and the power electronic apparatus is connected to the power line. The power electronic apparatus is configured to increase output impedance in a first PLC communication frequency band, to reduce interference from an output current of the power electronic apparatus to a PLC signal in the first PLC communication frequency band. The first PLC communication frequency band is a PLC communication frequency band in which the PLC signal transmitting end sends the PLC signal to the PLC signal receiving end. In this way, the interference from the power electronic apparatus to the PLC signal in the first PLC communication frequency band can be reduced without adding an additional passive filter.

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Shanghai, China

Kai Xin