Research On Key Technology And Develop On Equipment Of Distributed Energy Storage System

In recent years,the application of distributed grid-connected power generation systems based on renewable energy sources such as wind energy and solar energy has attracted the attention of all countries in the world and has presented a rapid development trend.Due to the intermittent and uncertain nature of this type of energy,as the proportion of new energy generation installed capacity in the power system continues to increase,the phenomenon of wind abandonment and abandonment is becoming more and more serious,with source-to-charge flexible conversion characteristics.Grid energy storage technologies and equipment have become an important way to improve the power grid’s ability to absorb new energy sources.The distributed energy storage system can be used with various types of new energy distributed generation systems or independently applied at the load side to achieve peak load reduction,peak shaving,frequency regulation,and optimization of power quality.It is an important component of active distribution networks and microgrids.section.This paper takes the distributed electrochemical energy storage system as a target,and focuses on the research and development of bidirectional converter detection and control technology,equipment development and system application solutions based on existing achievements at home and abroad.The specific tasks include:First,the basic working principle and charge-discharge characteristics of leadacid batteries are summarized and analyzed.Combined with the application environment of lead-acid batteries in energy storage systems,it is clear that bidirectional converters can achieve lead-acid batteries by comparing various typical charge-discharge methods.Three-stage charging control specific requirements and related parameters selection method.Second,a comprehensive analysis of pq and ip-iq current detection methods based on instantaneous reactive power theory and a novel ip-iq detection method based on instantaneous voltage vector orientation were conducted.The new ip-iq based on instantaneous voltage vector orientation was further studied.Detection technology in the specific application of bidirectional converters.Thirdly,based on the direct current control technology of two-level voltagebased converters,through the analysis of the control effects of each switch mode on the output current in the I-type three-level converter topology,the three-level I-type power supply is proposed.A novel pulse width modulation current tracking method for direct current control of flat bidirectional converters.Completed the I-type threelevel bidirectional converter main circuit,control system hardware and software design and prototype development.Fourth,the design of the distributed energy storage application system architecture was studied and the optimal control strategy of the distributed energy storage system with the aim of maximizing economic benefits under the time-of-use price policy was planned.Initially completed the establishment of a distributed energy storage system experimental platform and carried out related functional experiments.