Sungrow Power Supply Co., Ltd.

Haoyuan Li

Xiaodong Mei

Xiaoxun Li

Zhiqiang Han

Benhe Yang

Houlai Geng

Wei Sun

Qun Zheng

Kai Shen

Qingqing Xu

Changyou Wang

Jun Xing

Touming Wu

Chao He

Yang Song

Provided is a grid-connected inverter safety detection device applied in a photovoltaic inverter system and including voltage detection circuit, a filter circuit, a comparison circuit and a controller. The voltage detection circuit is configured to detect a voltage between the point N and the ground, or a voltage between the first terminal for any phase of the three-phase power grid and the ground. The filter circuit is configured to filter out an alternating current component of the voltage detected by the voltage detection circuit and to retain an direct current component of the voltage. The comparison circuit is configured to compare the direct current component of the voltage with a preset voltage value and transmit a comparison result to the controller. The controller is configured to determine, according to the comparison result, whether an alternating current side at the output terminal of the inverter has normal insulation.

Safety detection device and method of grid-connected inverter

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.

Method and device for generating PWM pulses for multi-level inverter

Growing community of inventors

Anhui, China

Haoyuan Li