电动汽车双向LLC谐振式充电模块的研究与设计

发布时间：2018-01-26 01:55

本文关键词： 电动汽车双向 LLC谐振 PFM　出处：《南京理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着电动汽车技术的快速发展,能够实现功率双向流动的充电模块在新能源等领域得到越来越广泛的应用。针对双向充电模块中的DC/DC部分,本文以Type-4型和Type-11型的谐振腔组合而成的双向LLC谐振式变换器为研究与设计对象。本文基于对双向LLC谐振式变换器工作状态的分析,建立了稳态模型,分析了谐振参数对变换器直流增益特性、谐振腔输入阻抗特性的影响,求解出了谐振腔各状态量的数学表达式,并分析得到了 MOSFET工作失效和实现ZVS软开关的条件。采用了扩展函数描述分析法,建立了变换器的小信号模型系统,重点分析了开关频率和负载变化对模型系统稳定性与动态响应特性的影响,为补偿器的参数设计提供了理论依据。根据电动汽车技术指标,设计了变换器主功率电路并进行损耗分析,为电路参数的进一步优化提供了参考依据。根据脉冲频率调制(Pulse Frequency Modulation,PFM)原理,自主设计了一套硬件控制电路,并在电路中增加了软启动电容,避免了在变换器启动时MOSFET进入失效模式。在Saber仿真软件中搭建双向LLC谐振式变换器的仿真模型,对谐振参数和控制参数进行了仿真分析与验证。并在此基础上搭建了实验平台,对变换器在双向运行模式下的电压电流波形以及效率进行测试,验证了参数设计的合理性与有效性。
[Abstract]:With the rapid development of the electric vehicle technology, the charging module which can realize the bidirectional power flow has been more and more widely used in the field of new energy and so on. Aiming at the DC/DC part of the bidirectional charging module. In this paper, a bidirectional LLC resonant converter composed of Type-4 and Type-11 resonators is studied and designed. Based on the analysis of the operating state of the bidirectional LLC resonant converter. Analysis. The steady state model is established, and the influence of resonant parameters on DC gain characteristic and input impedance characteristic of resonant cavity is analyzed, and the mathematical expression of each state quantity of resonator is solved. The working failure of MOSFET and the condition of realizing ZVS soft switch are analyzed. The small signal model system of converter is established by using the method of extended function description. The influence of switching frequency and load on the stability and dynamic response characteristics of the model system is analyzed, which provides a theoretical basis for the parameter design of the compensator. The main power circuit of the converter is designed and the loss is analyzed. It provides a reference for the further optimization of circuit parameters, according to the pulse Frequency modulation principle of pulse frequency modulation. A set of hardware control circuit is designed, and the soft-start capacitor is added in the circuit. The failure mode of MOSFET is avoided when the converter is started, and the simulation model of bi-directional LLC resonant converter is built in the Saber simulation software. The resonant parameters and control parameters are simulated and verified. On this basis, an experimental platform is built to test the voltage and current waveform and efficiency of the converter in bi-directional operation mode. The rationality and validity of parameter design are verified.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM46

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