【作者】 王建新；

【导师】 杨世彦；

【作者基本信息】 哈尔滨工业大学 ， 电气工程， 2011， 硕士

【摘要】 近年来蓄电池由于具有容量大、功率密度高等优点而被广泛应用于煤矿电机车、不间断电源等多种领域。充电电源作为蓄电池的能量补给设备与蓄电池相生相伴,其性能的优劣直接影响蓄电池整体性能。而传统的充电电源开关损耗大、充电效率低、功率密度低。因此研究高效、高功率密度的充电电源具有十分重要的意义。通过分析目前充电电源的研究现状,采用软开关电源拓扑是提升充电电源效率和功率密度的有效方法,对比研究了常用软开关电源拓扑的优缺点,根据恒流充电电源的运行特点,确定采用串联负载谐振变换器和半桥LLC谐振变换器两种谐振软开关变换器作为恒流充电电源的主电路拓扑,同时为了实现大功率输出,对两单元串联负载谐振变换器的交错并联做了进一步研究。根据充电电源的恒流输出特性要求和串联负载谐振变换器在不同工作方式下的特点,确定了变换器在谐振电流断续的方式下工作,分析了变换器在该种工作方式下的工作原理,探讨了实现开关管ZCS软开关的条件,并分析了在低压大电流工作条件下适用于串联负载谐振变换器的整流电路结构。针对串联负载谐振变换器调频控制的特点,对两单元串联负载谐振变换器交错并联的控制方式进行了研究,设计了定脉宽调频移相的交错控制方案。对主电路和控制电路进行了设计,并对两单元串联负载谐振变换器交错并联进行了仿真验证。分析了半桥LLC谐振变换器在两个不同开关频率区间的工作原理,并利用基波分析法建立了变换器的等效模型,在该模型基础上分析了半桥LLC谐振变换器的电流传输特性和电压增益特性,并结合变换器的输入阻抗特性分析了实现ZVS软开关的条件。在分析结果基础上设计了电路参数,并对其进行了仿真验证。通过实验平台的搭建,分别对两单元串联负载谐振变换器的交错并联和半桥LLC谐振变换器进行了实验验证。实验结果表明:串联负载谐振变换器适合采用全桥整流方式进行整流,两个串联负载谐振变换器单元在交错并联工作状态下均可以实现ZCS软开关,且两单元交错并联效果良好,总输出电流纹波得到改善;半桥LLC谐振变换器在整个工作过程中均可实现ZVS软开关,两种电路拓扑均可在较高的效率下恒流充电。更多还原

【Abstract】 Storage battery has been widely used in mine electrical vehicle and uninterruptible power supply because of the large capacity and high power density in recent years. The charging power supply as the energy supply equipment is closely linked to storage battery and its performance affects the overall performance of storage battery. The conventional charging power supply has high switching losses, low efficiency and low power density. So it is very meaningful to research the charging power supply with the features of high efficiency and high power density.This paper analyzes the current status of charging power supply and identifies that soft-switching technique is the effective method to increase efficiency and power density. According to the advantages and disadvantages of common soft-switching topologies and the operating characteristics of constant current charging power supply, the main circuit of current charging power supply is identified to use series load resonant converter and half-bridge LLC resonant converter. This paper does a further research on the interleaved parallel technique of two series load resonant converter units.According to the condition of constant current output and the features under different operating modes of series load resonant converter, it is clear that resonant current of converter should be operated in discontinuous mode. The ZCS condition of switch is discussed through analyzing principle of the converter. The rectifier structure of series load resonant converter on low-voltage and high-current conditions is also analyzed. This paper also researches the interleaved parallel control mode of two series load resonant converter units. Fixing pulse width, adjusting frequency and shifting phase is used to the control method. Main circuit and control circuit are designed and the simulation of interleaved parallel converter with two series load resonant converter units is carried out.The working principle of the half-bridge LLC resonant converter in two different switching frequency ranges is analyzed. The equivalent model of the converter by the fundamental analysis method is built. The current transmission character and the voltage gain are analyzed based on the model of the half-bridge LLC resonant converter, and the condition to achieve ZVS soft-switching is analyzed combined with the input impedance character of the converter. The circuit parameters are designed based on the analysis results, and the simulation is carried out.The two units interleaved paralleled series load resonant converter and the half-bridge LLC resonant converter are verified by experiments through the experimental platform. The experimental results show that full-bridge rectifier is suitable for series load resonant converter , and both of the two series load resonant converter units working at the interleaved paralleled state can achieve ZCS soft-switching, and the effect of the two interleaved paralleled units is well, the ripple of the total output current is improved. And the ZVS soft-switching can be realized throughout the whole process of the half-bridge LLC resonant converter. The efficiency with constant current charging of the two circuit topologies is high.更多还原