【摘要】 传统的直流变换器一般都是在变压器初级串联直流隔直电容,以消除直流磁偏和保证变压器伏秒平衡。分析了隔直电容在直流全桥变换器中的影响。为了实现软开关,系统需要更大的串联谐振电感,由此会产生更大的占空比丢失,使得变换器的效率更低。为此,提出了一种基于数字化实现的峰值电流控制方法,用以实现变压器初级的直流磁偏控制,从而省去变压器初级的隔直电容。基于TMS320LF2407A型DSP构造了2kW的移相全桥变换器的实验平台,实验结果验证了所述方案的合理性和有效性。更多还原

【Abstract】 Traditionally,connecting the blocking capacitor in series with the primary wind is an easy way to eliminate the DC flux bias to ensure volt-second unbalance of the transformer in phase-shift full-bridge converter.However,it conse-quently brings much undesirable influence that relatively large leakage inductance is required and duty cycle loss is greater than that of no blocking capacitor case,which results in lower efficiency.This paper analyzes the various influences of the blocking capacitor in details.To achieve higher efficiency,proposes a digital "peak current"control and realizes DC flux bias control on the primary side of the transformer,which removes the blocking capacitor.In the end,the experimental results based on the experimental prototype of 2kW phase-shift full-bridge converter using DSP TMS320LF2407A verify the correctness and feasibility of the proposed control scheme.更多还原