基于移相全桥ZVS变换器的电动汽车直流充电电源设计

发布时间：2019-04-17 20:44

【摘要】：随着电力电子技术的进步发展，开关电源以其高频、高效、高功率密度、体积小等优点，逐渐取代线性电源，成为主流。软开关技术可以使开关电源的电磁干扰问题得到改善，且可提高系统效率，成为近年来电力电子技术的研究热点。在各类软开关电源电路中，移相全桥ZVS变换器两个桥臂均工作在零电压开通软开关条件下，，开关损耗小，结构简单，易于控制，且不增加开关管应力，因此广泛应用于中、大功率电路。本文对基于移相全桥ZVS变换器及DSP数字控制的电动汽车地面充电机进行了理论分析与详细设计。文章首先通过比较目前电动汽车直流充电电源常用的充电方法及DC-DC拓扑结构，选取移相全桥电路作为主电路结构以及两段式智能充电方法，并给出了充电电源系统结构。其次介绍了本文所采用的功率电路拓扑结构即移相全桥ZVS变换器工作原理，研究了该类变换器所存在的诸如副边占空比丢失、副边整流电压振荡等缺点，给出了解决方法，并以此为基础对主要元件进行了参数设计然后基于Buck变换器小信号模型，对移相全桥ZVS变换器进行建模，得出控制系统的开环函数，并通过仿真观察其波特图。设计了以DSP芯片TMS320F28335为基础的控制电路，包括检测电路、开关管驱动电路、辅助电源、保护电路等，并对相关参数进行了计算。最后以Matlab/Simulink软件对设计的系统电路进行了仿真，并在20kW样机上进行了相关实验。实验结果表明：充电系统参数设计合理，移相全桥变换器成功实现ZVS，满足系统性能要求。数字控制软件工作正常，检测保护电路能及时准确对故障信号进行检测保护，输出电压稳定。验证了系统设计的准确可靠性。
[Abstract]:With the development of power electronics technology, switching power supply has become the mainstream because of its advantages such as high frequency, high efficiency, high power density, small volume and so on. Soft-switching technology can improve the electromagnetic interference problem of switching power supply and improve the system efficiency, which has become a hot research topic of power electronics technology in recent years. In all kinds of soft switching power supply circuits, the two bridge arms of phase-shifted full-bridge ZVS converter operate under the condition of zero-voltage on soft-switching, the switching loss is small, the structure is simple, the structure is easy to control, and the stress of switch is not increased, so it is widely used in the field. High power circuit. In this paper, the ground charger of electric vehicle based on phase-shifted full-bridge ZVS converter and DSP digital control is analyzed and designed in detail. Firstly, by comparing the common charging methods and DC-DC topology of DC charging power supply for electric vehicles, the phase-shifting full bridge circuit is selected as the main circuit structure and the two-stage intelligent charging method, and the charging power supply system structure is given. Secondly, the principle of phase-shifted full-bridge ZVS converter, which is the topology of power circuit adopted in this paper, is introduced. The disadvantages of this kind of converter, such as the loss of duty cycle of the secondary side and the voltage oscillation of the secondary side rectifier, are studied, and the solutions are given. Then based on the small-signal model of the Buck converter, the phase-shifted full-bridge ZVS converter is modeled, and the open-loop function of the control system is obtained, and the baud diagram of the control system is observed by simulation. The control circuit based on DSP chip TMS320F28335 is designed, including detection circuit, switch driving circuit, auxiliary power supply, protection circuit, etc., and the related parameters are calculated. Finally, the system circuit is simulated with Matlab/Simulink software, and the related experiments are carried out on the 20kW prototype. The experimental results show that the charging system parameters are reasonably designed and the phase-shifted full-bridge converter (ZVS,) is successfully implemented to meet the system performance requirements. The digital control software works normally, the detection and protection circuit can detect and protect the fault signal in time and accurately, and the output voltage is stable. The accuracy and reliability of the system design are verified.
【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;U469.72

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