Photovoltaic power generation system, power control device and energy storage system

Abstract

The invention provides a photovoltaic power generation system, a power control device and an energy storage system, which are used for stabilizing the total power of the direct current side of the photovoltaic power generation system and avoiding power fluctuation. The photovoltaic power generation system comprises a plurality of photovoltaic cells, a direct-current / direct-current conversion module, a direct-current bus capacitor, an energy storage assembly and a power control device; the input side of the direct-current / direct-current conversion module is coupled with the plurality of photovoltaic cells, the output side is coupled with the direct-current bus capacitor, and the direct-current / direct-current conversion module is used for adjusting the running state of each photovoltaic cell and outputting electric energy provided by the photovoltaic cells to the direct-current bus capacitor; the energy storage assembly is coupled with the direct-current bus capacitor and used for storing or providing electric energy; the power control device is coupled with the direct-current bus capacitor and the energy storage assembly and is used for detecting the first voltage of the direct-current bus capacitor and controlling the energy storage assembly to charge the direct-current bus capacitor when the first voltage meets a preset compensation condition; and the direct-current bus capacitor is used for coupling the load.

Description

technical field [0001] The present application relates to the technical field of photovoltaic power generation, and in particular to a photovoltaic power generation system, a power control device and an energy storage system. Background technique [0002] In order to detect the performance parameters of photovoltaic cells in photovoltaic power generation systems, such as multi-peak scanning, IV curve scanning, etc., it is usually necessary to adjust the output voltage of photovoltaic cells (also the input voltage to the DC / DC conversion module), which will cause the photovoltaic power generation system. The DC side input power fluctuates. For example, when scanning the IV curve of a photovoltaic cell, the open circuit voltage of the photovoltaic cell generally decreases gradually to the short circuit voltage, or increases from the short circuit voltage to the open circuit voltage. As the output voltage of the photovoltaic cell changes, the output current of the photovoltaic...

AI Technical Summary

Problems solved by technology

As the output voltage of the photovoltaic cell changes, the output current of the photovoltaic cell under test also changes accordingly, causing the output power of the photovoltaic cell under test to be unstable, that is, power fluctuations occur

like figure 1 As shown, this will cause power fluctuations in the input power of the DC side of the inverter in the photovoltaic power generation system, resulting in large fluctuations in the output power of the inverter's AC side, affecting the grid connected to the photovoltaic power generation system, such as causing grid accidents

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