Hybrid energy storage system and micro power grid system

Abstract

The invention provides a hybrid energy storage system and a micro power grid system and aims to solve a problem that a hybrid energy storage system in the prior art requiring an energy management unit to determine charging / discharging power of a storage cell and charging / discharging power of a super capacitor is relatively complex to realize. The hybrid energy storage system comprises a first type bidirectional power converter, a first type energy storage device, a second type bidirectional power converter and a second type energy storage device, wherein a charging / discharging speed of the first type energy storage device during charging / discharging is changed by the first type bidirectional power converter according to a preset charging / discharging speed change rate when a value of a physical parameter of a bus changes; the charging / discharging speed of the first type energy storage type device during charging / discharging is not changed when the value of the physical parameter is equal to a first parameter value or a second parameter value; the second type bidirectional power converter is used for charging / discharging the second type energy storage device when the parameter value reaches a boundary value of a preset scope, the parameter value is made to not surpass the boundary value of the preset scope, and the first parameter value and the second parameter value are both in the preset scope.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a hybrid energy storage system and a microgrid system. Background technique [0002] At present, in islands and remote areas, micro-grids are generally used for power supply, that is, they mainly rely on new energy sources such as photovoltaic power generation, wind power generation, and tidal power generation. Because of the intermittent nature of these new energy sources, these new energy sources cannot provide continuous and reliable power supply. Therefore, an energy storage system is needed in the microgrid system to maintain the stability of electric energy. [0003] At present, batteries and supercapacitors are generally used to form a hybrid energy storage system. Batteries have high energy density, but frequent high-current charging and discharging will shorten their life, while supercapacitors have high charging and discharging power and long cycle life, but l...

AI Technical Summary

Problems solved by technology

[0007] The embodiment of the present invention provides a hybrid energy storage system and a microgrid system to solve the problem that in the existing hybrid energy storage system, the energy management unit needs to determine the charging and discharging power of the storage battery and the charging and discharging power of the supercapacitor. This will lead to more complex system implementation, which limits the application of grid systems using hybrid energy storage systems

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