Photovoltaic power station system with low voltage ride through and anti-islanding protection functions

Abstract

The invention discloses a photovoltaic power station system with low voltage ride through and anti-islanding protection functions. The photovoltaic power station system comprises a photovoltaic power generation system array, a first breaker, a three-phase inverter, a filter, a parameter detecting module, a loader, a second breaker, a transformer, a power grid and a controller. The output current of the photovoltaic power generation system array sequentially passes through the first breaker, the three-phase inverter and the filter to be input into the input end of the parameter detecting module, one path of the parameter detecting module is connected with the loader, the other path of the parameter detecting module is connected with the power grid through the transformer and the second breaker, the parameter detecting module can detect switch signals of the second breaker and the voltage V and the frequency f of the coupled point between the parameter detecting module and the loader and input the switch signals, the voltage V and the frequency f to the input end of the controller, one path of the output end of the controller is connected with the inverter to provide PWM signals to the inverter, and the other path of the output end of the controller is connected with the first breaker. The photovoltaic power station system combines the low voltage ride through function and the anti-islanding protection function, so that the purpose of improving the stability and the safety of the photovoltaic power station system is achieved.

Description

technical field [0001] The invention relates to the field of photovoltaic power generation, in particular to a photovoltaic power station system with low-voltage ride-through and anti-islanding protection functions. Background technique [0002] Low-voltage ride-through technology (LVRT) was first proposed in wind power generation systems. For photovoltaic power generation systems, when the voltage of photovoltaic grid-connected points drops, photovoltaic equipment can maintain grid-connection, and even provide a certain amount of reactive power to the grid. The grid is restored until the grid returns to normal, thereby "riding" this low voltage time (area). With the rapid increase of the installed capacity of solar photovoltaic power generation, the power grid has higher requirements for the low voltage ride-through capability of grid-connected photovoltaic power plants. Photovoltaic power plants must be able to operate uninterruptedly connected to the grid when the extern...

AI Technical Summary

Problems solved by technology

[0005] Now photovoltaic power plants only have the function of low voltage ride through or anti-islanding protection, which poses a great threat to photovoltaic power plants

Due to the contradiction between the low-voltage ride-through and anti-islanding protection of the photovoltaic power station, the island protection malfunctions during the low-voltage ride-through process, which threatens the safe and stable operation of the power grid. The protection refuses to move, thus causing equipment damage and threatening the personal safety of maintenance personnel; and islanding detection is mainly divided into communication-based islanding detection and partial islanding detection

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