高增益Z源逆变器研究

发布时间：2018-03-23 00:20

本文选题：Z源逆变器　切入点：宽输入　出处：《南京航空航天大学》2015年硕士论文　论文类型：学位论文

【摘要】：宽输入高增益逆变器在新能源开发领域起着至关重要的作用,它将新能源输出低压直流转换为高压交流电输出。目前,Z源逆变器做为宽输入逆变器中的一个研究热点,具有桥臂无死区、输出波形THD小、可靠性高的优点,得到了国内外学者的广泛关注。在保留Z源逆变器优点的同时,进一步提升其电压增益,满足新能源发电低输入电压的要求,具有重要的研究意义。本文首先对耦合电感类Z源逆变器进行了拓扑推衍,介绍了该类逆变器的工作原理和调制策略,比较了该类逆变器不同拓扑的电压增益、器件应力以及耦合电感的体积,总结了耦合电感类Z源逆变器的特点。其次,在开关电感准Z源逆变器基础上,将开关电感单元的一个二极管替换为电容,提出一种基本升压单元准Z源逆变器,给出了该逆变器的工作原理及逆变器的各项特性分析,进一步提升了电压增益;在基本升压单元准Z源逆变器基础上,将升压单元两电感耦合,提出一种耦合电感升压单元准Z源逆变器,减少了一个无源器件的使用,并利用耦合电感漏感来抑制二极管电流峰值,分析了耦合电感匝比、漏感、直通占空比以及输入平均电流对增益的影响,制作了一台原理样机,进行了相关实验验证。随后,本文将Z源逆变器的应用拓展到隔离场合,提出一种不对称全桥Z源逆变器,分析了该逆变器的工作原理,制作了原理样机。为使Z源网络工作于对称状态以减少采样电路,同时减小Z源网络中二极管的电压应力,提出对称式全桥Z源逆变器,列出了其参数设计原则,制作了原理样机并进行实验验证。最后,为避免前级变换器桥臂直通,使整个系统依旧保持Z源可靠性高的特点,本文提出一种交错双管正激Z源逆变器,前级采用交错双管正激变换器。分析了该变换器的工作原理,列出了参数设计及主要的实现电路等,制作了相应的原理样机并验证了理论分析的正确性。本文研究的高增益Z源逆变器,针对Z源逆变器的缺点,进一步提升了电压增益,在实现相同增益时采用了更短的桥臂直通时间,减小桥臂直通状态下功率器件的导通损耗,提高效率。
[Abstract]:Wide input high gain inverter plays an important role in the field of new energy development. It converts the new energy output from low voltage DC to high voltage AC output. It has the advantages of no dead-time, small output waveform THD, high reliability, and has been widely concerned by scholars at home and abroad. While preserving the advantages of Z-source inverter, the voltage gain of the inverter is further enhanced. It is of great significance to meet the requirements of low input voltage of new energy generation. First of all, the topology of the coupled inductor class Z source inverter is derived, and the working principle and modulation strategy of this kind of inverter are introduced. The voltage gain, device stress and the volume of coupling inductor of this kind of inverter are compared, and the characteristics of Z-source inverter with coupling inductor are summarized. Secondly, based on the switching inductance quasi-Z-source inverter, By replacing a diode of the switch inductance unit with a capacitor, a basic boost unit quasi-Z source inverter is proposed. The working principle of the inverter and the characteristics of the inverter are analyzed. The voltage gain is further enhanced. Based on the basic booster unit quasi Z source inverter, a coupling inductance boost unit quasi Z source inverter is proposed, which reduces the use of a passive device. The coupling inductor leakage inductance is used to suppress the diode current peak. The effects of the coupling inductor turn ratio, leakage inductance, direct duty cycle ratio and input average current on the gain are analyzed. In this paper, the application of Z-source inverter is extended to the isolation situation, and an asymmetric full-bridge Z-source inverter is proposed. The working principle of the inverter is analyzed, and a prototype of the principle is made. In order to make the Z-source network work in symmetrical state to reduce the sampling circuit, At the same time, the voltage stress of diode in Z-source network is reduced, a symmetrical full-bridge Z-source inverter is proposed, the design principle of its parameters is listed, the prototype of the principle is made and verified by experiment. Finally, in order to avoid the straight-through of the bridge arm of the front converter, In this paper, an interleaved two-switch forward Z-source inverter is presented, in which the interleaved two-switch forward converter is used in the front stage. The working principle of the converter is analyzed. The parameter design and main realization circuits are listed, the corresponding principle prototype is made and the correctness of the theoretical analysis is verified. The high gain Z-source inverter studied in this paper has further enhanced the voltage gain in view of the shortcomings of the Z-source inverter. When the same gain is realized, a shorter through time is adopted to reduce the on-loss of the power device and improve the efficiency of the power device in the straight-through state of the bridge arm.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM464

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