基于BUCK变压器变压模式建模与仿真

发布时间：2018-04-13 18:00

本文选题：Buck变换器 + 电压反馈　；参考：《东北石油大学》2015年硕士论文

【摘要】：随着电力电子技术的发展,以全控型电力电子器件为核心的开关变换器已广泛应用于家用电器、计算机和工业控制领域。由于全控型电力电子器件工作在开关模式,整机变换效率非常高,以逐步取代传统的线性电源。开关变换器将朝着高频化、高功率密度、低压大电流方向发展。本文首先研究传统线性电源的组成及工作原理,建立线性电源仿真模型,分析参数对电压纹波的影响,理论和仿真研究表明调节闭环电压放大倍数对于电压纹波具有重要的意义,增大闭环电压放大倍数可以减小电压纹波。线性电源调整管工作在放大区,调节开关管两端的压降保持输出电压的稳定,从而导致线性电源的效率比较低,发热严重,需要散热器,体积和重量比较大。在线性电源研究的基础上,以降压型Buck变换器为主要研究对象,分析Buck变换器的组成和工作原理,建立Buck变换器仿真模型,仿真研究Buck变换器输入输出电压、电感电流、电容电流和二极管上的各点波形,验证理论分析的正确性。采用状态空间平均法建立Buck变换器的数学模型,以电压负反馈组成闭环系统的动态结构图,研究系统的开环对数幅频特性和相频特性,控制-输出传递函数、输入-输出传递函数和开环输出阻抗。分析系统的稳定性及其动态性能,仿真研究验证上述理论的正确性。最后,本文以28V输入12V/4A输出的电源为例,在稳态情况下根据开关电源性能指标要求进行稳态参数计算,设计电感和电容,分析功率级传递函数、反馈系统传递函数和系统的开环传递函数是否满足设计指标要求,建立闭环控制系统的仿真模型。仿真结果满足设计指标要求。
[Abstract]:With the development of power electronics technology, switching converters with full control power electronic devices as the core have been widely used in the fields of household appliances, computers and industrial control.Because the full control power electronic devices work in switching mode, the conversion efficiency of the whole machine is very high, which replaces the traditional linear power supply step by step.Switching converter will develop towards high frequency, high power density, low voltage and high current.In this paper, the composition and working principle of the traditional linear power supply are studied, the simulation model of the linear power supply is established, and the influence of the parameters on the voltage ripple is analyzed.The theory and simulation results show that adjusting the closed-loop voltage amplification is of great significance to the voltage ripple, and increasing the closed-loop voltage amplification can reduce the voltage ripple.The linear power supply adjusting tube works in the amplifier region, and the voltage drop at the two ends of the switch tube keeps the output voltage stable, which leads to the low efficiency of the linear power supply, serious heating, the need of radiator, large volume and weight ratio.Based on the research of linear power supply, this paper analyzes the composition and working principle of Buck converter, establishes the simulation model of Buck converter, and studies the input and output voltage and inductance current of Buck converter.The capacitive current and the waveforms on the diode verify the correctness of the theoretical analysis.The mathematical model of Buck converter is established by state space averaging method. The dynamic structure diagram of closed loop system is composed of voltage negative feedback. The open loop logarithmic amplitude-frequency characteristic and phase-frequency characteristic of the system are studied, and the control-output transfer function is also studied.Input-output transfer function and open loop output impedance.The stability and dynamic performance of the system are analyzed, and the simulation results verify the correctness of the above theory.Finally, taking the 28V input 12V/4A output power supply as an example, the steady-state parameters are calculated according to the performance requirements of the switching power supply under steady state, inductance and capacitance are designed, and the power level transfer function is analyzed.Whether the feedback system transfer function and the open loop transfer function meet the design requirements, the simulation model of the closed-loop control system is established.The simulation results meet the design requirements.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM46

【相似文献】