On The Study Of Digital Control Technique Of High-Frequency Switching-Mode Power Supply

Digital control technique is becoming more and more popular in the field of switching-mode power supplies (SMPSs). It usually consists of three key building blocks: analog-to-digital converter (ADC), digital compensator and digital pulse-width modulator. However, because of the increasing swithing frequency, conventional digital control technique can no longer satisfy the technical requirement of SMPSs, such as power conversion efficiency, static and dynamic response characteristics, complexity, size, weight and cost. That increases the price-performance ratio to the controller of high-frequency SMPSs, and then slows down its commercialization.This thesis has summarized the most advanced digital control techniques for high-frequency SMPSs reported in the world, and made an introduction and a classification on ADC structures to improve its completion in theory. To accelerate the process of researches on digital controller of high-frequency SMPSs, the thesis has proposed initiative technique solutions in 2 aspects: ADC structure based on exponitial quantization and proportional-feed-forward (PFF) control algorithmADC structure based on exponential quantization has many advantages, such as high conversion precision, large conversion range, low conversion delay, simple structure, and small memory size required by compressed addressing characters for look-up tables. As the results for the digital controller, it can provide larger regulation range of the output voltage, better control characteristics, simplify the circuit structure, reliability improvement and cost decrease.PFF control algorithm can provide excellenet line regulation performances against input voltage variation, and has good steady-state performance, fast transient response, low computation complexity and delay. Therefore, it can improve the control characteristics, simply the circuit structure and reduce the cost of the digital controller.All the work done in the thesis is to increase performance-cost ratio of the digital controller for high-frequency SMPSs, and accelerate their commercialization.