DC-DC变换器环路增益测试方法的再认识与补偿器的设计

发布时间：2018-05-30 09:18

本文选题：DC-DC变换器 + 环路增益　；参考：《华中科技大学》2015年硕士论文

【摘要】：DC-DC变换器的环路增益可以用来优化控制参数,使DC-DC变换器具有良好的稳定性和动态性能。利用网络分析仪可以对DC-DC变换器的环路增益进行测试,测试方法主要有调制波扰动测试法和脉宽扰动测试法,它们的测试结果存在差异。本文研究这两种测试方法测得的环路增益不同的原因,并分析哪种测试方法是准确的,进而利用环路增益的理论测试结果,提出补偿器的设计思路。第二章介绍调制波扰动测试法和脉宽扰动测试法的基本原理,然后分析PWM调制器的混叠效应及其产生的边带频率分量,在此基础上推导调制波扰动测试法和脉宽扰动测试法的理论环路增益,并揭示这两种环路增益存在差异的原因。提出两种与脉宽扰动测试法等效的测试方法,即PWM调制测试法和采样保持测试法,它们的电路实现更为简洁。最后对三类基本的DC-DC变换进行实验测试,测试结果验证了以上分析及所提出的测试方法的正确性。第三章利用两种测试方法所测得的环路增益对DC-DC变换器的稳定性和跟随性能、抗扰性能进行分析。分析表明,这两种环路增益都是有效的,其中,脉宽扰动测试法测得的环路增益分析稳定性时更方便,而调制波扰动测试法分析跟随性能和抗扰性能时更加直观。然后给出环路增益的计算方法,并对DC-DC变换器的稳定性和跟随性能进行实验验证,实验结果验证了本文分析的正确性。第四章针对采用后沿调制和前沿调制的三类基本DC-DC变换器,分析边带频率分量对两种环路增益的影响,指出它们均受到了边带频率分量的影响,且使用脉宽扰动测试法测得的环路增益设计补偿器更加方便。利用脉宽扰动测试法测得的环路增益,提出了考虑边带频率分量影响的补偿器设计思路,并进行了实例设计及实验验证,实验结果验证了提出的设计方法的有效性。
[Abstract]:The loop gain of DC-DC converter can be used to optimize the control parameters and make the DC-DC converter have good stability and dynamic performance. The loop gain of DC-DC converter can be tested by network analyzer. The main methods are modulation wave disturbance test method and pulse width perturbation test method. This paper studies the reasons why the loop gain measured by the two methods is different, and analyzes which test method is accurate, and then puts forward the design idea of the compensator based on the theoretical test results of the loop gain. In chapter 2, the basic principles of modulation wave perturbation test and pulse width perturbation measurement are introduced, and then the aliasing effect of PWM modulator and its sideband frequency component are analyzed. On this basis, the theoretical loop gain of the modulation wave perturbation testing method and the pulse width perturbation testing method are deduced, and the reasons for the differences between the two kinds of loop gains are revealed. Two kinds of test methods are presented, which are equivalent to the pulse width perturbation method, that is, the PWM modulation test method and the sample-and-hold test method. Their circuit implementation is more concise. Finally, three kinds of basic DC-DC transform are tested, and the test results verify the correctness of the above analysis and the proposed test methods. In chapter 3, the stability, following performance and immunity performance of DC-DC converter are analyzed by using the loop gain measured by two kinds of test methods. The analysis shows that the two kinds of loop gain are effective, in which the loop gain measured by the pulse width perturbation method is more convenient to analyze the stability, while the modulation wave disturbance test method is more intuitive in analyzing the following performance and the disturbance rejection performance. Then the calculation method of loop gain is given, and the stability and follow performance of DC-DC converter are verified by experiments. The experimental results verify the correctness of the analysis in this paper. In chapter 4, the influence of sideband frequency component on the gain of the two loops is analyzed for the three basic DC-DC converters using back-edge modulation and forward modulation, and it is pointed out that they are all affected by the sideband frequency component. And the loop gain design compensator obtained by pulse width disturbance test is more convenient. Based on the loop gain measured by the pulse width perturbation method, the design idea of the compensator considering the influence of sideband frequency component is proposed. An example is designed and the experimental results show that the proposed design method is effective.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM46

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