微电网储能双向DC-DC变换器研究与设计

发布时间：2018-03-31 16:35

本文选题：双向DC/DC变换器　切入点：倍流　出处：《武汉理工大学》2014年硕士论文

【摘要】：双向DC/DC变换器在电动汽车、电能质量调节、储能系统和可再生能源发电等领域具有广阔的应用前景。本文以微电网储能为应用背景，对一种全桥倍流双向DC/DC变换器的控制方法进行较为深入的研究。本文首先概述双向DC/DC变换器的应用前景和研究意义，比较分析了几种典型的双向DC/DC变换拓扑结构，，选择一种电压-电流型全桥倍流电路作为光伏微电网储能双向DC/DC变换器的主电路拓扑；该双向DC/DC变换器的低压侧接储能电池组，为倍流整流结构，两个滤波电感电流交错并联，有效减小电池电流纹波，高压侧为全桥结构，接直流母线。针对变换器电流源端的启动问题，在电感上增加反激绕组的方式实现电路的软启动。本文还分析了全桥倍流双向DC/DC变换器在各模态下的工作原理和电气特性，并进行了原理性仿真。其次，建立了全桥倍流双向DC/DC变换器主电路数学模型。讨论了环路控制器的类型选择，确定用电感电流反馈作为内环、用端口电压反馈作为外环的双环控制策略。由于双向DC/DC变换器存在Buck和Boost两种主要的工作状态，在这两种工作状态下，主电路的小信号模型存在明显差异，本文根据电路的具体工作状态不同，给出相应的电流内环和电压外环的控制框图，并对环路控制器参数进行详细设计。微电网储能双向DC/DC变换器存在多种工作模态，本文采用多模态控制技术，详细分析各种模态之间的切换条件，设计相应的模态切换逻辑。双向DC/DC变换器的开关管驱动逻辑复杂，工作状态频繁切换，控制算法复杂，本文采用DSP TMS320F28069设计了数字控制系统。本文还详细论述了全桥倍流双向DC/DC变换器的主电路设计，包括主功率变压器、电感设计，滤波电容的选型以及主电路中开关管的选型等。最后，用PSIM中的C语言模块实现变换器的数字控制系统，对全桥倍流双向DC/DC变换器进行了系统仿真分析。设计制作了实验样机，并进行实验研究。仿真结果和实验结果均表明，所研究的全桥倍流双向DC/DC变换器具有良好的稳态和动态性能。
[Abstract]:Bidirectional DC/DC converters have broad application prospects in electric vehicles, power quality regulation, energy storage systems and renewable energy generation. The control method of a full bridge double current bidirectional DC/DC converter is studied in detail. In this paper, the application prospect and research significance of bidirectional DC/DC converter are summarized, and several typical bidirectional DC/DC converter topologies are compared and analyzed. A voltage-current-mode full-bridge current-doubling circuit is selected as the main circuit topology of the photovoltaic microgrid energy storage bidirectional DC/DC converter, which has a low-voltage side energy storage battery pack with a current-doubling rectifier structure, and two filter inductors are staggered in parallel. The current ripple of the battery is reduced effectively, the high voltage side is a bridge structure, and the DC bus is connected. The soft start of the circuit is realized by adding flyback winding to inductance. The operating principle and electrical characteristics of full bridge double current bidirectional DC/DC converter are analyzed in this paper, and the principle simulation is carried out. Secondly, the mathematical model of the main circuit of the full bridge double current bidirectional DC/DC converter is established, the type selection of the loop controller is discussed, and the inductance current feedback is used as the inner loop. The port voltage feedback is used as the double loop control strategy of the outer loop. Due to the existence of two main working states of Buck and Boost in the bi-directional DC/DC converter, the small signal model of the main circuit is obviously different in these two working states. According to the different working state of the circuit, the control block diagram of the current inner loop and the voltage outer loop are given in this paper, and the parameters of the loop controller are designed in detail. There are many operating modes in the bidirectional DC/DC converter for microgrid energy storage. In this paper, the switching conditions between different modes are analyzed in detail by using multi-mode control technology. The switch tube driving logic of bi-directional DC/DC converter is complex, the operation state is frequently switched, and the control algorithm is complex. In this paper, the digital control system is designed with DSP TMS320F28069, and the main circuit design of the full bridge double current bi-directional DC/DC converter is discussed in detail, including the main power transformer, inductance design, filter capacitance selection and switch transistor selection in the main circuit. Finally, the digital control system of the converter is realized by C language module in PSIM, and the system simulation analysis of the full bridge double current bidirectional DC/DC converter is carried out, and the experimental prototype is designed and manufactured. The simulation results and experimental results show that the proposed full-bridge current-doubling bi-directional DC/DC converter has good steady-state and dynamic performance.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM46

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