Abstract：When the inverter operates in boundary current mode under light load,the switching frequency increases significantly,the switching loss increases greatly and the efficiency decreases significantly.To solve this problem,this paper proposes that when the inverter output power drops to the set value,the working mode is switched to discontinuous condition mode (DCM); and the switching time is changed according to the input voltage,output voltage and output power to reduce the switching frequency and switching losses of the inverters,thereby improving light-load efficiency.The working principle of the DCM mode with variable turn-off time is analyzed in detail and the theoretical calculation is deduced.In addition,considering the influence of parasitic parameters on inductor current,the quality of light-load current is improved by triggering the peak value of inductor current through hardware comparator.Its control strategy is also introduced.The simulation and experimental results show that the discontinuous current mode with variable turn-off time improves the efficiency by about 2% at light load and the quality of the output current is pretty good,which verifies the proposed method.
郎天辰, 杜士祥, 尹浩, 胡海兵. 基于可变关断时间断续电流模式的全桥逆变器轻载效率优化方法[J]. 电工技术学报, 2020, 35(22): 4761-4770.
Lang Tianchen, Du Shixiang, Yin Hao, Hu Haibing. Optimizing Method for Light-Load Efficiency of a H-Bridge Inverter Based on Variable Turn-Off Time Discontinuous Current Mode. Transactions of China Electrotechnical Society, 2020, 35(22): 4761-4770.
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2020, Vol. 35 
