升压直流变换器的关键技术研究

发布时间：2018-05-16 00:15

本文选题：直流变换器 + 高增益　；参考：《上海电力学院》2017年硕士论文

【摘要】：传统能源的匮乏、环境污染的加剧、电力需求的增长,使得大力发展清洁能源成为可持续发展战略的重要选择。升压直流变换器在以绿色能源为一次能源的应用场合中具有极其重要的作用,比如在分布式发电系统、新能源汽车、LED灯驱动和有源功率因数校正等领域。传统Boost变换器因结构简单被广泛使用,然而其电压增益有限。提高电压增益的方法有很多,而拓扑的创新对于在低成本的条件下提高升压直流变换器的电压增益更具有一定的优势。本文在当前发展的直流变换器升压技术的基础上,从拓扑创新的角度提出了几种新型的高增益直流变换器。首先,论文利用耦合电感技术,提出了基于耦合电感的新型高增益软开关直流变换器,详细分析了该变换器的拓扑结构、不同的工作模态及电路中参数的选择依据,并与其它变换器进行了性能对比。研究结果证明该变换器具有几个优势:(1)该变换器实现了从耦合电感匝比和占空比多自由度来调控电压增益,突破了传统升压变换器中仅由占空比来调整电压比的局限;(2)全部开关器件上的电压应力都比输出电压低;(3)该变换器的功率开关管能软开通,二极管能在零电流状态下自然关断,大大缓解了反向恢复问题,电路损耗降低。其次,论文利用Z源网络技术,提出了基于Z源网络的高增益低应力的直流变换器,文中对该变换器的拓扑结构、工作原理和稳态性能进行了讨论,并与其它变换器进行了性能对比分析。研究结果证明本变换器具有的几个优势:(1)该变换器利用Z源网络进一步提升了电压增益,避免占空比工作在接近1的情况;(2)该变换器的结构使得功率开关管两端的电压应力明显降低;(3)Z源网络中的电容纹波可以相互抵消,有助于降低电路中的纹波。最后,论文结合开关电容技术,提出了带有电感-电容结构的高增益Boost变换器,文中介绍了该变换器的拓扑结构和其在连续导通模式和断续导通模式下的工作原理,给出了不同变换器间性能对比分析及该变换器所涉及的参数设计。研究结果证明本变换器具有的几个优势:(1)该变换器在开关管导通时利用开关电容增加了电感-电容结构两端的充电电压,在开关管关断时电感和电容的串联放电,从而变换器的电压增益大大提升,这种方式能降低开关管的占空比;(2)该变换器占空比的减小能有效降低开关管上的电流纹波,电路损耗得以降低。论文中提出的新型升压直流变换器,具有高增益、低应力的优势,使其适用于低压新能源发电系统等场合。
[Abstract]:Due to the shortage of traditional energy, the aggravation of environmental pollution and the increase of electricity demand, the development of clean energy has become an important choice of sustainable development strategy. Booster DC / DC converters play an important role in applications where green energy is used as primary energy, such as distributed generation systems, new energy vehicles driving LED lights and active power factor correction (APFC). Traditional Boost converter is widely used because of its simple structure, but its voltage gain is limited. There are many ways to improve the voltage gain, and the topology innovation has a certain advantage to improve the voltage gain of the boost DC converter under the condition of low cost. In this paper, based on the current development of DC converter boost technology, several new high gain DC / DC converters are proposed from the viewpoint of topology innovation. Firstly, a novel high gain soft-switching DC / DC converter based on coupling inductance is proposed, and its topology, different working modes and the selection of parameters in the circuit are analyzed in detail. The performance of the converter is compared with that of other converters. The results show that the converter has several advantages: (1) the converter can control the voltage gain from the coupling inductor turn ratio and duty cycle multiple degrees of freedom. It breaks through the limitation that only duty cycle is used to adjust the voltage ratio in the traditional boost converter. (2) the voltage stress on all switching devices is lower than the output voltage. 3) the power switch of the converter can be turned on soft, and the diode can be turned off naturally at zero current state. The reverse recovery problem is greatly alleviated and the circuit loss is reduced. Secondly, a high gain and low stress DC / DC converter based on Z source network is proposed in this paper. The topology, working principle and steady state performance of the converter are discussed. The performance of the converter is compared with that of other converters. The results show that the converter has several advantages: 1) the converter uses the Z-source network to further enhance the voltage gain. The structure of the converter makes the voltage stress at the two ends of the power switch obviously reduce the capacitance ripple in the power switch network, which is helpful to reduce the ripple in the circuit. Finally, a high gain Boost converter with inductance and capacitor structure is proposed, and its topology and its working principle in continuous and intermittent on-mode are introduced. The performance comparison and analysis among different converters and the design of parameters involved in the converter are given. The results show that the converter has several advantages: (1) the switching capacitor is used to increase the charging voltage at both ends of the inductor-capacitor structure, and the series discharge between the inductor and the capacitor is achieved when the switch is off. Thus, the voltage gain of the converter is greatly increased, and the duty cycle of the switch can be reduced by this way. The decrease of the duty cycle can effectively reduce the current ripple on the switch and reduce the circuit loss. The new boost DC / DC converter proposed in this paper has the advantages of high gain and low stress, which makes it suitable for low voltage new energy generation system.
【学位授予单位】：上海电力学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM46

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