Optimum Design of Switching Regulators by means of Computer-Aided-Design Technique

开关稳压电源分为两个阶段，一个是功率转换阶段，另一个是反馈控制阶段。功率转换级采用Buck、Boost、Buck-Boost等多种电路。另一方面，针对传统的控制方法，提出了一种多回路控制方法。在这种多环控制方法中，不仅将输出电压作为常规的反馈信号，还将电抗器电流、输出电流或输出电压的差值作为被控变量。除了电抗器的集肤效应和邻近效应以及…寄生电感的影响外，采用状态空间平均法可以精确地得到功率变换级的特性更多的赛道。因此，在输出电压是唯一控制变量的常规情况下，通过使用静态和动态特性的预定表达式来完成输出滤波器的设计方法。然而，动态稳定性是制约LC滤波器设计的一个重要因素，它强烈地依赖于反馈控制方法。特别是采用多环反馈技术，可以显著提高开关稳压电源的稳定性。本文研究了Buck-Boost变流器中通过积分变压器两端的电压来等效检测电抗器电流的多回路反馈技术，并从理论和实验上阐明了多回路反馈技术可以扩大变流器的稳定区域，使平滑电容小型化。仿真结果表明，多环反馈控制技术在改善系统稳定性和抗噪性方面优于广泛应用的传统PD(比例+微分)控制技术。其次，解析地揭示了谐振型变流器的基本特性，该变流器在MHz的高开关频率下具有高效率和低噪声的突出特点，这些结果是开发开关变流器CAD系统的必要材料。较少

Switching regulators consist of two stages; one is a power conversion stage, and the other is a feedback-control stage. Several kinds of circuits such as buck, boost and buck-boost converters are used as the power conversion stage. On the other hand, a multi-loop control method is proposed as opposed to a conventional control method. In this multi-loop control method, not only the output voltage, which is the conventional feedback signal but also the reactor current, or the output current, or the differential value of output voltage are used as controlled variables.In this research, at first, a design method for an output filter composed of a reactor and a smoothing capacitor has been investigated which has much influence on the stability of boost and buck-boost converters. The characteristics of the power-conversion stage can be obtained precisely by the state-space-averaging method except the skin effect and proximity effect of reactor, and the effect of parasitic inductances of the … More circuit. Therefore, the design method for the output filter has been accomplished by using the predetermined expressions of the static and dynamic characteristics in the conventional case that the output voltage is an only control variable. However, the dynamic stability which is a constraint to the design of LC filter strongly depends on the method of feedback control. Especially, the stability of switching regulators can be improved considerably by adopting the multi-loop feedback technique. This research has investigated the multi-loop feedback technique where a reactor current is sensed equivalently by integrating the voltage across the transformer in the buck-boost converter, and it has been clarified analytically and experimentally that the multi-loop feedback technique can expand the stable region of the converter and miniaturize the smoothing capacitor. Furthermore, it is shown that the multi-loop feedback technique is superior for the stability improvement and the noise immunity to the conventional PD(proportional+differential) control technique used widely. Next, a basic characteristic has been revealed analytically for a resonant converters which has the prominent features such as high efficiency and low noise at high switching frequency of MHz, and these results are essential materials to develop the CAD system for switching converters. Less