交错并联式双管正激变换器和控制电路毕业论文.doc

. . . . PAGE / NUMPAGES . . . . 摘 要 本文主要研究了交错并联式双管正激变换器与其控制电路。相比于其他隔离式DC/DC变换器，交错并联结构的双管正激变换器有自动实现励磁能量的回馈，结构简洁等优点。同时，其主功率管只需承受电源电压，从而选择面更广。此外，其并联结构缩小了输出滤波电感的体积，降低了器件的应力，从而进一步减小了损耗。在控制电路的设计方面，考虑到电源输出电压围的可控性，本文采用电压反馈控制方式，选用UC3825型脉宽调制器。本文列举了DC/DC变换的各种拓扑，比较了四种PWM控制模式，分析了交错并联式双管正激变换器的工作原理与其工作过程，详细推导并建立了带有电压反馈控制的双管正激变换电路的小信号模型，设计了补偿网络，给出了主电路和控制电路的工程计算。最后，对系统进行频域、时域仿真，并给出相关分析。 关键词：双管正激变换器、电压反馈控制、小信号模型、补偿网络、仿真 Abstract This paper studies the parallel dual interleaved forward converter and its control circuit. Different to other isolated DC/DC converters, the parallel dual interleaved forward converter can feedback excitation energy automatically, also, simple structure is the one of thesystem’s advantages. Meanwhile, the power switches only need to work just under the main power voltage, whichmakes the designers have a wider range of choosing the power switches. In addition, the parallel structure reduces the volume of the output filter inductance, reducing the stress of the device, thereby, further reducing the loss. In the control circuit design, taking into account of the controllability of the range of the output voltage, we use voltage feedback control method, and chose theUC3825 voltage pulse width modulator. This article lists the DC/DC conversion of the various topologies, makes a comparison of thefour PWM control modes, analyzes the parallel dual interleaved forward converter’s operating principle and working process, derives in detail and establish the small signal model, designs the compensation network, and carries out the main circuit’s and control circuit’s engineering calculation. Finally, this paper makes the system frequency and time domain simulation, and make some correlation analysis. Key words:dualforward converter, voltage feedback control,small signal model, compensation network, simulation 目 录 TOC \o "1-3" \h \z \u 摘要 I Abstract I 目录 II 第1章绪