数字DC-DC开关变换器的建模与自适应控制研究

发布时间：2018-03-15 22:03

本文选题：数字DC-DC开关变换器　切入点：连续时间模型　出处：《合肥工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：DC-DC开关变换器能够进行直流电能变换,以满足各种负载的供电要求,被广泛应用于信息、通信、能源等关键领域。随着工业和科技的发展,各种负载对DC-DC开关电源的功能和性能提出了越来越高的要求。与传统的模拟控制方法相比,数字控制不仅具有高灵活性、可编程性等特点,而且可以采用更先进的控制算法来提高开关变换器的性能。因此,由模拟控制转向数字控制将成为未来开关变换器的发展趋势。本文以Buck开关变换器为例,分别对模拟和数字DC-DC开关变换器进行建模仿真与验证,并对数字自适应补偿控制方法进行研究和分析。具体工作包括:系统分析DC-DC开关变换器在不同工作模式下的工作过程,建立其连续时间模型,并考虑电路寄生参数,对非理想Buck变换器进行建模分析。建立数字DC-DC离散z域模型,分析离散化过程中采样、保持和量化等问题。采用自适应补偿控制方法,当负载发生变化时,通过自适应调整系统的补偿系数,提高系统稳定性,降低系统误差和延时,改善系统瞬态性能。通过Matlab/Simulink平台,采用自适应补偿控制算法对数字DC-DC开关变换器模型进行系统仿真、优化,并对其进行稳态、负载扰动等分析。仿真结果表明,开关频率为100kHz到1MHz时,系统输出电压变化稳定在5V,瞬态响应时间为0.22ms,验证了所研究控制方法的正确性。
[Abstract]:DC-DC switching converters are capable of DC energy conversion to meet the power supply requirements of various loads, and are widely used in key fields such as information, communications, energy, etc. With the development of industry and technology, The functions and performance of DC-DC switching power supply are demanded more and more by various loads. Compared with the traditional analog control method, digital control not only has the characteristics of high flexibility and programmability. Moreover, more advanced control algorithms can be used to improve the performance of switching converters. Therefore, the conversion from analog control to digital control will become a trend in the future. This paper takes Buck switching converters as an example. Modeling, simulation and verification of analog and digital DC-DC switching converters are carried out, and digital adaptive compensation control methods are studied and analyzed. The specific work includes: systematically analyzing the working process of DC-DC switching converters in different operating modes. The continuous time model is established and the parasitic parameters of the circuit are considered to model and analyze the non-ideal Buck converter. The discrete z domain model of digital DC-DC is established to analyze the sampling in the process of discretization. When the load changes, the compensation coefficient of the system can be adjusted adaptively to improve the stability of the system and reduce the system error and delay. The transient performance of the system is improved. The digital DC-DC switching converter model is simulated and optimized by adaptive compensation control algorithm based on Matlab/Simulink platform. The steady state and load disturbance are analyzed. The simulation results show that, When the switching frequency is 100kHz to 1MHz, the output voltage of the system is stable at 5V and the transient response time is 0.22ms. the correctness of the proposed control method is verified.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM46

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