【作者】 陈庆学；

【导师】 南余荣；

【作者基本信息】 浙江工业大学 ， 控制理论与控制工程， 2009， 硕士

【摘要】 本文致力于滑模变结构控制方法在DC-DC变换器中应用的研究,对几种实用性强的滑模变结构控制方案进行了分析和讨论,其中,针对基于滞环调制的传统滑模变结构控制器切换频率不固定的问题,提出的一种基于PWM调制的滑模变结构控制方法是本文的重点。在理论分析的基础上进行了Matlab/Simulink仿真试验,仿真结果表明该滑模变结构控制方案能得到恒定的切换频率,同时有效地改善了变换器在输入和负载扰动时的动态性能和鲁棒性。首先回顾了开关变换器的各种控制方法,并总结了各自具有的优缺点,重点介绍了滑模变结构控制理论及其在开关变换器中应用的研究动态,通过对国内外相关研究的分析,指出了目前滑模变结构控制开关变换器中存在的若干问题。其次,对滑模变结构控制理论的相关基本概念和性质进行了专门介绍,并对滑模变结构控制与传统的线性控制相结合的方法进行了研究,仿真结果表明该方法有效地消除系统稳态误差,提高了滑模变结构控制的实用性。再次,针对传统滑模变结构控制的切换频率不固定问题,提出了一种基于PWM调制的滑模变结构控制方法,通过此方法有效地降低了切换频率和简化前端和后级滤波电路的设计。然后,将此方法应用于DCM工作模式下DC-DC变换器的控制中,解决了传统滑模变结构控制因所得到的切换频率不固定而引起严重的开关损耗、电感和变压器磁芯损耗以及电磁干扰等问题,从而使得滑模变结构控制在功率变换器中的应用更加广泛。最后,将滑模变结构控制与传统的PID控制在变换器中的应用效果进行了对比研究,仿真结果进一步证实了滑模变结构控制所表现出来的优势。更多还原

【Abstract】 A central purpose of this dissertation is to research the application of sliding mode variable structure control in DC-DC converters, a few applied sliding mode variable structure control schemes are analyzed and discussed extensively. In order to get a constant switching frequency, a approach to the design of PWM-based sliding mode variable structure controllers for DC-DC converters is proposed. Based on the theoretical analysis, simulations are carried out in Matlab/Simulink, the results show that sliding mode variable structure control schemes can acquire a constant switching frequency, improve the dynamic property and robustness of DC-DC converter under input voltage and load perturbations.Firstly, an overview of control techniques for switching converter is given and the advantages and disadvantages of the control schemes are described, particularly introduce the sliding mode variable structure control theory and the research trend of its application to the switching converter. According to the review of the recent research progress, the existing problems of sliding mode variable structure control for switching converter are indicated.Secondly, basic conceptions and properties of sliding mode variable structure control are introduced and the combination of the sliding mode variable structure control and traditional linear control scheme is developed. Simulation results show this approach can eliminate the steady state error and improve the practicability of sliding mode variable structure control schemes effectively.Thirdly, according to the varying switching frequency of traditional sliding mode variable structure control, the combination of sliding mode variable structure control and traditional PWM control scheme is developed. The switching frequency of sliding mode control is constricted within a practical range and the design of the input and output filters is simplified by this method. Then PWM-based sliding mode variable structure control scheme is implemented in DCM DC-DC converters, solving the issues of excessive switching losses, inductor and transformer core losses, and electromagnetic interference (EMI) effectively which caused by the varying and high switching frequency of general sliding mode variable structure control.Lastly, a comparative study on the properties of sliding mode variable structure control and PID control in converter, the simulation results show that the robustness and dynamic performance of sliding mode control is better than PWM-based PID control.更多还原