Hybrid energy storage system based on ordered energy control

Abstract

The invention relates to a hybrid energy storage system comprising various energy storage carriers. The system is mainly based on an ordered energy control strategy, the energy storage carriers are selectively discharged in a current-limiting or power-limiting mode through a pulse width modulation (PWM) closed-loop control principle and a monitoring system selective control principle, the advantages of the energy storage carriers are combined and complemented, the disadvantages of the energy storage carriers are overcome, and the aim of ordered energy utilization of different energy storage carriers is fulfilled according to a discharge priority sequence, namely a third energy storage subsystem, a second energy storage subsystem and a first energy storage subsystem. By the hybrid energy storage system, the phenomenon that the power of a power grid fluctuates because a wind and light power generation system or a high-power load and the like are connected to the power grid is avoided, smoothing compensation is realized, the quality of electric energy is improved, and the stable operation of the power grid is ensured.

Description

technical field [0001] The invention relates to a power system energy storage system and method, in particular to a hybrid energy storage system based on energy orderly control. Background technique [0002] As the country continues to promote the development of smart grids, micro-grids, renewable energy and electric vehicles, energy storage technology, which is its key technical support, has also achieved rapid development. At present, the common forms of energy storage can be divided into four categories: electrochemical energy storage, physical energy storage, electromagnetic energy storage and phase change energy storage. Among them, energy storage methods such as physical energy storage, electromagnetic energy storage, and phase change energy storage cannot be developed and applied on a large scale due to limitations in technical level, geographical environment, operating conditions, and initial investment costs. However, with the continuous breakthrough of electrochem...

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Problems solved by technology

Lead-acid battery energy storage system has low mass-to-energy ratio and volumetric energy ratio and fewer cycles, and it is easy to cause certain pollution in the process of mass production or recycling; lithium-ion battery energy storage system has high raw material cost and production process Complexity makes it expensive. In addition, lithium-ion batteries have strict requirements on charge and discharge control and operating environment, and have exploded in the case of overcharge, overdischarge or overtemperature, posing safety hazards; supercapacitor battery energy storage systems Its discharge time is short and its specific energy is low, which cannot meet the requirements of continuous power supply to the grid

Therefore, in order to better meet the grid's requirements for energy storage systems with high capacity, long life, high energy storage and release, smooth pulse charging peaks, and low initial investment costs, it is necessary for the energy storage system to have high specific power and high cycle time. Life and other characteristics, and at the same time can effectively reduce the energy storage system investment cost, floor space, self-weight, etc., but the energy storage system using a single energy storage carrier cannot meet the above requirements

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