Sungrow Power Supply Co., Ltd.

Xiaoxun Li

Yanfei Yu

Anying Jiang

Xinyu Wang

Xiaodong Mei

Haoyuan Li

Zhiqiang Han

Zhifei Zhang

Kai Shen

Benhe Yang

Zongjun Yang

Hua Ni

Yu Yang

Chao He

Yang Song

Touming Wu

Haifeng Yang

Shun Ding

Fenglei Wu

Liu Su

An inverter and a method for identifying a fault on an alternating current side of a photovoltaic system are provided. A controller records a waveform of a preset parameter of the photovoltaic system, and then transmits the recorded waveform to an external device. The external device that performs relatively excellently in data storage and processing stores the waveform and performs subsequent processing, to accurately recognize the fault on the alternating current side of the inverter. Further, the fine waveform can be seen from the external device, so that the accuracy of system monitoring is greatly improved. Moreover, the external device analyzes the waveform and generates a control instruction to accurately control the inverter due to advantages of storage capacity, big data, and computing power. In addition, system performance can be optimized in cooperation with a local control unit.

Inverter and alternating current fault identification method for photovoltaic system

Provided are a method for controlling operation of a module level power electronics (MLPE) device, a method for controlling MLPE devices and a photovoltaic system. In the method for controlling operation of a MLPE device, if it is determined that a current of a photovoltaic string where the MLPE device is located is less than a current threshold and coding information sent by a converter in the photovoltaic system is not received for a first preset time period, an output voltage or an output power of the MLPE device is controlled to be less than a corresponding threshold.

Method for controlling operation of MLPE device, method for controlling MLPE devices, and photovoltaic system

A photovoltaic system, a method for locating devices in a photovoltaic string, a MLPE apparatus, and a method for ranking MLPE apparatuses. Each MLPE apparatus sends, actively according to a predetermine rule, an initial message to the other MLPE apparatuses. The initial message includes a serial number corresponding to said MLPE apparatus and an accumulated operation duration of said MLPE apparatus. The MLPE apparatuses determine the rank of the accumulated operation duration of each MLPE apparatus according to the initial messages sent from all MLPE apparatuses. After each MLPE apparatus communicates with a communication host, the MLPE apparatuses reports the rank of the accumulated operation duration of each MLPE apparatus to the communication host. Thereby, the communication host may determine a physical location of each device in the photovoltaic string according to the ranks of the accumulated operation durations and a sequence of installing positions of the devices in the photovoltaic string.

Method of ranking MLPE apparatuses and locating devices in a photovoltaic string

An intelligent switch device and a power generation system are provided. The intelligent switch device includes a first power port, a second power port, a switch unit and a control unit. A first end of a switch unit is connected to a first power supply via a first power port, and a second end of the switch unit is connected to a second power supply via a second power port. The control unit is configured to control the switch unit to be turned on for a first time period when the first power supply is in abnormal condition, where the abnormal condition causes the switch unit to be tripped. The first time period is greater than or equal to a time period required for a device to respond to the abnormal condition.

Intelligent switch device and power generation system

A photovoltaic inverter, a photovoltaic system, and a method for controlling discharging are provided. The photovoltaic inverter includes a first DCDC converter, an inverter circuit, a first discharging circuit, and a controller. A port capacitor is connected between a positive input end and a negative input end of the first DCDC converter. The port capacitor includes an X capacitor and a first group of Y capacitors. The first discharging circuit is connected between a common terminal of the first group of Y capacitors and a direct current bus, where the common terminal of the first group of Y capacitors is grounded. The controller is configured to control, when receiving a rapid shutdown instruction, the first discharging circuit to operate. The first discharging circuit is configured to discharge electrical energy of the port capacitor.

Photovoltaic inverter, photovoltaic system, and method for controlling discharging

A photovoltaic system and a method for locating devices in a photovoltaic string. A communication host in the photovoltaic system acquires accumulated operation durations of MLPE apparatuses of the photovoltaic string, ranks the accumulated operation durations to obtain a ranking result, and determines a physical location of each device in the photovoltaic string according to the ranking result and a sequence of installing positions of the devices, where the devices are installed at the installing positions based on the sequence. It is not necessary to paste label codes on the MLPE apparatuses, or record serial numbers of the MLPE apparatuses by installation personnel. Operation processes are simplified, operation time is saved, and labor costs are reduced.

Photovoltaic system and method for locating devices in photovoltaic string

A method for capacity expansion of an energy storage system and an energy storage system are provided. The method is applied to a controller in the energy storage system. The controller acquires a value of a characteristic parameter of a to-be-added second energy storage device as a target characteristic value. Then, the controller controls a charge/discharge power converter to charge or discharge first energy storage devices until a proximity of a value of a characteristic parameter of at least one first energy storage device to the target characteristic value is less than a preset proximity. Finally, a signal indicating that the second energy storage device is allowed to be connected into the energy storage system is generated and outputted to notify an operator.

Energy storage system and method for capacity expansion thereof

A power conversion system, a controller for the same, and a method for controlling the same. The power conversion system includes a shutdown array and a power converter. The shutdown array includes multiple shutdown strings that are connected in parallel. Each of the multiple shutdown strings includes multiple shutdown devices, where outputs of the multiple shutdown devices are connected in series. An output terminal of the shutdown array is connected to an input terminal of the power converter. An input terminal of each of the multiple shutdown devices is connected to at least one direct-current power supply. The controller sends a shutdown instruction to each shutdown device of the shutdown array in response to receiving a rapid-shutdown command, controls the power converter to discharge an input capacitor of the power converter, and stops discharging the input capacitor in response to an input voltage of the power converter being reduced to a preset voltage.

Power conversion system, controller for the same, and method for controlling the same

A three-level photovoltaic inverter pulse width modulation method and a three-level photovoltaic inverter pulse width modulator. The method includes: when it is detected that potential safety hazards exist in a three-level photovoltaic inverter, switching the pulse width modulation mode of the three-level photovoltaic inverter into a 13-vector space vector pulse width modulation mode, to solve the fault or abnormal problems in the three-level photovoltaic inverter such as midpoint potential offset or excessively large common mode leakage current formed when the ground stray capacitance of a photovoltaic assembly is large, wherein according to the 13-vector SVPWM mode, 12 short vectors in 27 on-off state vectors of the three-level photovoltaic inverter are abandoned, and only six long vectors, six middle vectors and three zero vectors are reserved.

Three-level photovoltaic inverter pulse width modulation method and modulator

A method for start control of photovoltaic inverter, a system thereof, and a photovoltaic power generation system are provided. A fan of the photovoltaic inverter is controlled to operate in a case that input voltage of the photovoltaic inverter is greater than a start threshold, and the fan operation is used as a load. Input voltage drop before and after the fan operates is obtained, and in a case that the input voltage drop is less than or equal to a voltage determination threshold, the photovoltaic inverter is controlled to start a grid connection. The voltage determination threshold is changed based on a power determination threshold of the photovoltaic inverter.

Method for startup control of photovoltaic inverter, system thereof, and photovoltaic power generation system

A method and a device for generating PWM pulses for an inverter are provided. The three-phase inverter's characteristic of including high frequency complementary switches is used. Only three PWM peripheral units of a DSP control unit are used to output PWM high frequency signals, and a detection control unit determine for each phase two currently high frequency complementary switches according to the states of detected level signals outputted by a preset number of GPIO interfaces. The PWM high frequency signals are distributed for each phase to one of the two switches, and the PWM high frequency signals are inversed and then sent to the other one of the two switches. In addition, the states of other switches are maintained unchanged according to a preset correspondence between states of switches of a multi-level inverter and outputted level signals in different switching periods.

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Anhui, China

Xiaoxun Li