Huawei Digital Power Technologies Co., Ltd.

Huawei Technologies Co., Limited

Future Wei Technologies, Inc.

Huawei Digital Technologies Co., Ltd.

Yongbing Gao

Yanzhong Zhang

Xun Wang

Lei Shi

Tiansan Lin

Song Wan

Xinyu Yu

Jianqiang Wang

Jun Wang

Dong Chen

Chen Xiao Wang

Yunfeng Liu

Kai Xin

Fei Xu

Zhiwu Xu

Yanfeng Li

Roland Huempfner

Jianfei Lin

Yunyan Xu

Guoping Fan

Yunyu Tang

Dianbo Fu

Yang Hu

Zhipeng Wu

Changsheng Pei

Haibin Guo

Guilei Gu

Wei Shui

Zhen Cao

Chengfeng Jiang

Peng Dong

Chen Wang

Guangping Yang

Minghui Xu

Xiaoqian Meng

Jialong Xu

Niantao Jiang

Heling Zhang

Panpan Wang

Zhaopeng Liu

A photovoltaic system, a power supply system, and an insulation fault detection method. An insulation impedance detection circuit is connected between a bus and the ground. The bus includes the direct current positive bus, the neutral bus, or the direct current negative bus. The insulation impedance detection circuit includes at least a switch. The direct current negative bus is connected to the neutral bus by using an electrical element or a voltage source. A controller obtains insulation impedance based on voltages to ground of the bus that are separately corresponding to the switch before and after the switch is turned on, and determines, based on the insulation impedance, whether there is an insulation fault in the photovoltaic system, to perform protection in a timely manner.

Photovoltaic system, power supply system, and insulation fault detection method

This application describes examples of a direct current combiner box, a photovoltaic power generation system, and a fault detection method. In one example, the direct current combiner box includes a fault detection unit, a protection circuit, and a boost circuit. The fault detection unit detects an operating parameter of the direct current combiner box. The protection circuit sends a protection signal to the boost circuit when the operating parameter meets a specified condition. The protection signal is used to enable the boost circuit to adjust a first voltage of a photovoltaic array at an input end of the direct current combiner box to a second voltage. After receiving the protection signal, the boost circuit adjusts the first voltage of the photovoltaic array at the input end of the direct current combiner box to the second voltage.

Direct current combiner box, photovoltaic power generation system, and fault detection method

An impedance detection method and a photovoltaic system are provided to help reduce complexity and costs of impedance detection. The method includes: sampling a voltage between a direct current bus and a protective earthing at each of a first time point and a second time point, to obtain a first voltage value and a second voltage value; sampling a leakage current on the direct current bus at each of the first time point and the second time point, to obtain a first current value and a second current value; and calculating an insulation impedance value of a combiner box based on a difference between the first voltage value and the second voltage value and a difference between the first current value and the second current value, to determine whether impedance of the combiner box is abnormal.

Impedance detection method and photovoltaic system

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

An example system includes an inverter and at least one combiner box. The combiner box includes a plurality of direct current-direct current (DC-DC) circuits and one controller. The controller is configured to: when an output voltage of the combiner box is greater than or equal to a first preset voltage and less than or equal to a second preset voltage, control the combiner box to output a maximum power. When the output voltage of the combiner box is greater than the second preset voltage, the controller controls an output power of the combiner box to decrease as the output voltage increases. The second preset voltage is greater than the first preset voltage, and the maximum power is a sum of maximum powers of all photovoltaic strings connected to the combiner box.

Photovoltaic power generation system, power control method, and combiner box

This application provides a photovoltaic power generation system. The system includes at least one first photovoltaic module, a photovoltaic inverter, a first two-way DC/DC converter, and at least one first energy storage unit, and further includes at least one second photovoltaic module or at least one second energy storage unit. The photovoltaic inverter includes a DC/DC converter and a DC-AC inverter, where the DC/DC converter is electrically connected to the at least one first photovoltaic module, and the DC/DC converter is connected to the DC-AC inverter through a direct current bus. For the photovoltaic power generation system, photovoltaic arrays and energy storage devices can be configured flexibly to cope with peaks and troughs of power consumption.

Photovoltaic power generation system and photovoltaic power transmission method

Embodiments of this application provide a power conversion circuit, a power transmission system, and a photovoltaic device. The power conversion circuit includes: a first bridge arm, where the first bridge arm includes a first upper bridge arm and a first lower bridge arm; the first upper bridge arm includes a switching component connected between an input positive end and an output end; the first lower bridge arm includes a switching component connected between the output end and an input negative end; each of the switching components includes a switching transistor and a first diode anti-parallel connected to the switching transistor.

Power conversion circuit, power transmission system, and photovoltaic device

A linkage protection system includes an inverter, an anti-potential-induced degradation (PID) apparatus, and an insulation-monitoring apparatus. The anti-PID apparatus is configured to inject a voltage into an input end or an output end of the inverter, to increase or decrease a voltage-to-earth of a photovoltaic system. The insulation-monitoring apparatus is configured to inject an insulation-monitoring voltage into a direct current (DC) side or an alternating current (AC) side of the inverter. The anti-PID apparatus and the insulation-monitoring apparatus directly or indirectly communicate with each other, to learn of information about whether a peer apparatus is operating, and perform linkage control. The anti-PID apparatus and the insulation-monitoring apparatus operate in different time periods.

Linkage protection system and method for photovoltaic power station

A method and an apparatus for detecting a short circuit of an inverter, and an inverter are provided. A voltage of a common bus is increased when a plurality of boost circuits in the inverter are all in a non-working state, and after circuit parameters of input sides of all the plurality of boost circuits are detected, a boost circuit in which a diode is short-circuited in the plurality of boost circuits is further determined based on the circuit parameters of the input sides of the boost circuits. According to the method and the apparatus for detecting a short circuit of an inverter, and the inverter, circuit complexity of the inverter can be reduced, and circuit complexity of a photovoltaic power generation system including the inverter is reduced.

Method and apparatus for detecting short circuit of inverter, and inverter

This application discloses a photovoltaic device, a photovoltaic inverter, a system, and a power limit control method. The device includes a DC-DC converter circuit, an inverter circuit, and a controller. An input end of the DC-DC converter circuit is connected to a photovoltaic array, and an output end of the DC-DC converter circuit is connected to an input end of the inverter circuit. The controller is configured to: receive a power scheduling instruction, where the power scheduling instruction carries a power reference value; and when the power reference value is less than a power at a maximum power point, reduce an input current of the DC-DC converter circuit; or when an input voltage of the DC-DC converter circuit is greater than or equal to a preset voltage, increase an input current of the DC-DC converter circuit until an output power of an inverter becomes consistent with the power reference value.

Photovoltaic device, photovoltaic inverter, system, and power limit control method

A converter includes a power conversion circuit, a switching device, and a controller, and includes N phases, where N is 2 or 3. An input end of the power conversion circuit is connected to a direct current power supply, and the power conversion circuit converts a direct current output by the direct current power supply into an alternating current. The switching device includes at least the following two stages: a first-stage switching device and a second-stage switching device. The first-stage switching device and the second-stage switching device separately include N switches, and the N switches are connected in series to the N phases respectively. An output end of the power conversion circuit is connected to an alternating current power grid through the first-stage switching device and the second-stage switching device that are connected in series.

Power converter, photovoltaic power generation system, method, and apparatus

A method and an apparatus for detecting a solar cell of a photovoltaic plant. The method includes: obtaining a first infrared image and a second infrared image, where the first infrared image includes infrared image information corresponding to an ambient infrared signal reflected by a to-be-detected solar cell operating in a short-circuit state, the second infrared image includes infrared image information corresponding to an infrared signal emitted by the to-be-detected solar cell operating in a first state and infrared image information corresponding to an ambient infrared signal reflected by the to-be-detected solar cell, and the first state is another state other than the short-circuit state; and detecting, based on the first infrared image and the second infrared image, whether the to-be-detected solar cell has a defect.

Method, apparatus, and system for detecting solar cell of photovoltaic plant

A photovoltaic power generation system includes an inverter, a controller, and at least two direct current branch circuits. The leakage current detection apparatus is configured to: detect a leakage current of the direct current branch circuit on which the leakage current detection apparatus is located and send the leakage current to the controller. The controller is further configured to: when the photovoltaic power generation system runs and a value of a leakage current of the direct current branch circuit exceeds a preset range, determine that an insulation fault occurs on the direct current branch circuit. The system can determine the direct current branch circuit on which the insulation fault occurs in the photovoltaic power generation system, so that measures are taken in time for the direct current branch circuit on which the insulation fault occurs, to eliminate a potential safety hazard.

Photovoltaic power generation system and method

A power system is disclosed. Output terminals of a power supply or a DC-to-DC unit are cascaded to increase an output voltage, so as to reduce a current between the power supply or the DC-to-DC unit and the DC-to-AC unit, and resolve cost and loss problems of the cable from the power supply or the DC-to-DC unit to the DC-to-AC unit. In addition, according to the power system provided in the embodiments of this application, a quantity of cables from the power supply or the DC-to-DC unit to the DC-to-AC unit may be further reduced by cascading output terminals of the power supply or the DC-to-DC unit and cascading inputs of the DC-to-AC unit, thereby reducing system costs. In addition, in the power system provided in the embodiments of this application, cascaded input and isolated output of the DC-to-AC unit can reduce a specification of a power conversion device.

Power system

Embodiments of this application provide a power system. An output terminal of a power supply or a DC-to-DC unit is cascaded. In addition, according to the power system provided in embodiments of this application, a quantity of cables from the power supply or the DC-to-DC unit to the DC-to-AC unit may be further reduced by cascading an output terminal of the power supply or the DC-to-DC unit and cascading an input of the DC-to-AC unit.

Growing community of inventors

Shanghai, China

Yongbing Gao