电池储能的两级式功率变换系统研究

发布时间：2018-04-10 08:04

本文选题：电池储能系统　切入点：控制策略　出处：《广西大学》2014年硕士论文

【摘要】：进入二十一世纪后,世界能源格局的变化和环境污染的加剧促进了以风能、太阳能为代表的新能源发电并网技术的研究和应用。与其他类型储能系统相比,电池储能系统的经济效益高、使用条件限制少、安装维护方便灵活,在需配备储能的新能源并网发电以及电动汽车等应用终端的使用都比较广泛。储能变流器是电池储能系统的重要组成部分,是储能电池组和电网间电能传输的桥梁。因双向变流器在储能系统中起到的独特作用,对其的研究越来越广泛,而热点集中在灵活模块化且高效充放电的电路拓扑结构以及其控制策略这两个方面。本文以三电池组接入的两级式功率变换系统为主要研究内容,重点研究的是主电路参数设计和系统的控制策略,并通过Matlab仿真和小功率实验对其进行了验证。首先对几种常见的PCS拓扑结构进行对比和分析,结合并网PCS的设计要求,选择以双向DC-DC变流器与双向DC-AC变流器级联的两级式非隔离PCS作为基本功率变换单元,并对主电路中的直流母线支撑电容、网侧滤波器以及直流侧的升压电感、电池侧电容等关键参数进行了设计。其次,分析了两级式PCS工作原理及系统数学模型。论文利用子系统集成法对两级式PCS的三个主要组成部分：LCL滤波器、三相两电平DC-AC变流器及双向DC-DC变流器进行了详细建模设计,并给出了各自的简化模型用于控制器设计再次,对PCS的控制策略展开研究。根据DC-AC变流器和DC-DC变流器的控制原理,分析了两者的协调控制方法,研究了在统一控制策略下恒流、恒压二阶段式充放电控制。为提高系统性能,将DC-AC变流器直流母线外环控制器设计成模糊PI控制。利用MATLAB软件搭建了系统仿真模型并进行了仿真。论文最后对本文设计的由三个双向DC-DC变流器和一个双向DC-AC变流器组成的PCS进行了小功率实验,实验结果表明本文提出的设计方案并达到了设计的要求,验证了控制策略的正确性和可行性。
[Abstract]:After entering the 21 century, the change of the world energy pattern and the aggravation of the environmental pollution have promoted the research and application of the new energy generation grid technology represented by wind energy and solar energy.Compared with other types of energy storage system, battery energy storage system has higher economic benefits, less conditions of use, convenient and flexible installation and maintenance, and is widely used in the grid power generation of new energy sources and electric vehicles which need to be equipped with energy storage.Energy storage converter is an important part of battery energy storage system and a bridge between energy storage battery pack and power grid.Due to the unique role of bidirectional converters in energy storage systems, the research on them is more and more extensive, while the focus is on the flexible modularization and efficient charging and discharging circuit topology structure and its control strategy.This paper focuses on the design of the main circuit parameters and the control strategy of the system, and verifies it by Matlab simulation and small power experiment.Firstly, several common PCS topologies are compared and analyzed. Combined with the design requirements of grid-connected PCS, two-stage non-isolated PCS, which is cascaded by two-way DC-DC converter and bi-directional DC-AC converter, is chosen as the basic power conversion unit.The key parameters such as DC busbar supporting capacitor, grid-side filter, DC side boost inductor and battery side capacitance are designed.Secondly, the working principle and system mathematical model of two-stage PCS are analyzed.In this paper, three main components of two-stage PCS, namely: LCL filter, three-phase two-level DC-AC converter and bi-directional DC-DC converter, are modeled and designed by subsystem integration method, and their simplified models are given for controller design.Thirdly, the control strategy of PCS is studied.According to the control principle of DC-AC converter and DC-DC converter, the coordinated control method is analyzed, and the constant current, constant voltage two-stage charge / discharge control is studied under the unified control strategy.In order to improve the system performance, the DC-AC converter DC busbar outer loop controller is designed as fuzzy Pi control.The system simulation model is built by using MATLAB software and the simulation is carried out.At the end of the paper, the design of PCS composed of three bidirectional DC-DC converters and one bidirectional DC-AC converter is carried out in a small power experiment. The experimental results show that the proposed scheme meets the requirements of the design.The correctness and feasibility of the control strategy are verified.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM46;TM910

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