數位控制電流模式降壓型轉換器之研製

Design and Implementation of Digital-Controlled Current Mode Buck Converters

葉家安(Chia-An Yeh)

指導教授 ： 賴炎生

國立臺北科技大學/電資學院/電機工程系研究所/博士(2010年)

https://doi.org/10.6841/NTUT.2010.00210

摘要

本文旨在設計與分析數位化電流模式控制之直流-直流轉換器，首先利用狀態空間平均法建立連續時間下的轉換器數學模型，以數值積分法將連續時間系統下的電源轉換器模型轉換至離散時間系統下的電源轉換器模型。接著建立與實現以FPGA為控制平台的數位化峰值電流模式直流/直流轉換器，利用多重電流回授取樣與具斜率補償之電流命令完成峰值電流模式控制，並以峰值電流模式控制的數學模型設計一數位控制器及分析斜率補償對穩定度的影響，由模擬及實測結果驗證理論分析與設計。
再者，本文提出一應用於直流/直流電源轉換器的前緣調變預測型峰值電流控制模式，此控制模式以低取樣頻率的ADC所取樣的電感電流與系統參數預測下一切換週期所需之責任週期，且由分析證明無斜率補償機制亦可抑制一般峰值電流控制受擾動後不穩定的問題。前緣調變預測型峰值電流控制模式能提供DPWM等效於1-bit-dither控制，使得DPWM的有效解析度增加並降低有限週期震盪的發生，藉由電路模擬及實測結果驗證理論分析。
最後本文提出一自我啟動技術以改善控制參數需預先設定之問題，適合應用於低取樣頻率之數位電流模式控制，並以自我啟動技術來實現後緣調變峰值電流模式控制，由實驗結果驗證控制特性。

關鍵字

峰值電流模式 ； 預測型電流模式控制 ； 自我啟動技術

並列摘要

The objective of this dissertation is to design and implement the current mode controlled DC-DC converters. The continuous time-domain model of converter is established by state space average method. The discrete time-domain model is derived by its continuous time-domain model via numerical integration. An FPGA platform for digital-controlled DC-DC converter based upon peak current mode control is set up. Peak current mode control is realized by comparing the multi-sampled inductor current and its reference with slope compensation. The digital controller of peak current mode control is designed by discrete time-domain current mode model and the effect of slope compensation on stability is investigated. The theoretical analysis and design are verified by simulation and experimental results.
Moreover, the design of digital controller for power converter with predictive peak current mode control and leading edge modulation is presented. The duty cycle of the proposed control is predicted by parameters of converter and sampled inductor current which is sampled by ADC with low sampling frequency. By stability analysis, the oscillation issue caused by noise can be suppressed without requiring slope compensation. The effect of predictive peak current mode control with leading edge modulation on limit cycle oscillation is analyzed. Predictive peak current mode control with leading edge modulation is equivalent to adding a one-bit dither control to DPWM. Therefore, the effective resolution of DPWM can be increased and the limit cycle issue can be improved. Experimental results will be included to fully support the theoretical analysis.
Finally, a novel self-commissioning digital power converter control technique is presented. The proposed technique is used to solve the problem which requires the controller parameters in prior. The proposed self-commissioning technique can be applied to the digital-controlled converter with low sampling frequency. Experimental results based upon self-commissioning digital peak current mode with trialing-edge modulation are presented. The results verify the performance of proposed control technique.

並列關鍵字

Peak current mode ； Predictive current mode ； Self-commissioning technique

參考文獻

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