Energy storage system, balance control method of energy storage system and photovoltaic power generation system

Abstract

The invention provides an energy storage system, a balance control method of the energy storage system and a photovoltaic power generation system, and relates to the technical field of energy storage systems. The energy storage system comprises a controller and three power conversion branches. Each power conversion branch comprises a power conversion circuit, or each power conversion branch comprises at least two power conversion circuits which are connected in series. The second end of each power conversion circuit is connected with at least one battery cluster; each battery cluster comprises at least two energy storage modules which are connected in series, and each energy storage module comprises a direct current / direct current conversion circuit and a battery pack; the output end of each battery pack is connected with the input end of the corresponding DC / DC conversion circuit, and the output ends of the DC / DC conversion circuits are connected in parallel with the equalization bus. And the controller controls each DC / DC conversion circuit, so that the electric quantity of each battery pack in the battery cluster is balanced. By means of the scheme, the electric quantity balance capacity of the energy storage system is improved, and the influence of the battery short-plate effect is relieved.

Description

technical field [0001] The present application relates to the field of energy storage systems, and in particular to an energy storage system, a balanced control method for the energy storage system, and a photovoltaic power generation system. Background technique [0002] With the aggravation of energy shortage and environmental pollution in modern society, photovoltaic power generation, wind power generation and other power generation methods have been widely used. In addition, with the development of electrochemical battery technology and the sharp increase in production capacity, the cost of electrochemical batteries has dropped, bringing opportunities for electrochemical batteries to participate in the power storage of new energy power generation systems. Due to the characteristics of the energy storage system using electrochemical batteries, such as flexibility, controllability of charging and discharging, fast response capability and high energy density, the energy sto...

AI Technical Summary

Problems solved by technology

The equalization current of passive equalization is generally within 1 amp (A), and the capacity of a battery cell often reaches hundreds of ampere hours (Ah), so it is difficult to achieve fast equalization of power only by a small equalization current. The power balance ability is very limited, making the energy storage system more vulnerable to the impact of the battery short board effect

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