提出一种应用于电能存储装置测试系统中的新型交错并联Boost软开关变换器。该变换器采用一组部分复用的辅助网络,令主开关管实现了零电压(zero-voltage-transition,ZVT)开通与关断,辅助开关管实现了零电流(zero-current-transition,ZCT...提出一种应用于电能存储装置测试系统中的新型交错并联Boost软开关变换器。该变换器采用一组部分复用的辅助网络,令主开关管实现了零电压(zero-voltage-transition,ZVT)开通与关断,辅助开关管实现了零电流(zero-current-transition,ZCT)开通与部分零电压关断,降低了开关损耗,提升了电路效率。开关过程中的dv/dt、di/dt得以降低,从噪声源上改善了变换器电磁兼容(electromagnetic compatibility,EMC)性能,对高频段噪声抑制效果明显。对拓扑结构、工作过程进行了分析,对宽范围工作的有效性与EMC性能的改善进行了论证,并搭建了1.5 k W原理样机进行试验研究,试验结果验证了理论分析的正确性。展开更多
This paper presents a multi-mode control scheme for a soft-switched flyback converter to achieve high efficiency and excellent load regulation over the entire load range. At heavy load, critical conduction mode with v...This paper presents a multi-mode control scheme for a soft-switched flyback converter to achieve high efficiency and excellent load regulation over the entire load range. At heavy load, critical conduction mode with valley switching (CCMVS) is employed to realize soft switching so as to reduce turn-on loss of power switch as well as conducted electromagnetic interference (EMI). At light load, the converter operates in discontinuous conduction mode (DCM) with valley switching and adaptive off-time control (AOT) to limit the switching frequency range and maintain load regulation. At extremely light load or in standby mode, burst mode operation is adopted to provide low power consumption through reducing both switching frequency and static power dissipation of the controller. The multi-mode control is implemented by an oscillator whose pulse duration is adjusted by output feedback. An accurate valley switching control circuit guarantees the minimum turn-on voltage drop of power switch. The pro-totype of the controller IC was fabricated in a 1.5-μm BiCMOS process and applied to a 310 V/20 V, 90 W flyback DC/DC converter circuitry. Experimental results showed that all expected functions were realized successfully. The flyback converter achieved a high efficiency of over 80% from full load down to 2.5 W, with the maximum reaching 88.8%, while the total power consumption in standby mode was about 300 mW.展开更多
文摘提出一种应用于电能存储装置测试系统中的新型交错并联Boost软开关变换器。该变换器采用一组部分复用的辅助网络,令主开关管实现了零电压(zero-voltage-transition,ZVT)开通与关断,辅助开关管实现了零电流(zero-current-transition,ZCT)开通与部分零电压关断,降低了开关损耗,提升了电路效率。开关过程中的dv/dt、di/dt得以降低,从噪声源上改善了变换器电磁兼容(electromagnetic compatibility,EMC)性能,对高频段噪声抑制效果明显。对拓扑结构、工作过程进行了分析,对宽范围工作的有效性与EMC性能的改善进行了论证,并搭建了1.5 k W原理样机进行试验研究,试验结果验证了理论分析的正确性。
基金the National Natural Science Foundation of China (No. 90707002)the Natural Science Foundation of Zheji-ang Province, China (No. Z104441)
文摘This paper presents a multi-mode control scheme for a soft-switched flyback converter to achieve high efficiency and excellent load regulation over the entire load range. At heavy load, critical conduction mode with valley switching (CCMVS) is employed to realize soft switching so as to reduce turn-on loss of power switch as well as conducted electromagnetic interference (EMI). At light load, the converter operates in discontinuous conduction mode (DCM) with valley switching and adaptive off-time control (AOT) to limit the switching frequency range and maintain load regulation. At extremely light load or in standby mode, burst mode operation is adopted to provide low power consumption through reducing both switching frequency and static power dissipation of the controller. The multi-mode control is implemented by an oscillator whose pulse duration is adjusted by output feedback. An accurate valley switching control circuit guarantees the minimum turn-on voltage drop of power switch. The pro-totype of the controller IC was fabricated in a 1.5-μm BiCMOS process and applied to a 310 V/20 V, 90 W flyback DC/DC converter circuitry. Experimental results showed that all expected functions were realized successfully. The flyback converter achieved a high efficiency of over 80% from full load down to 2.5 W, with the maximum reaching 88.8%, while the total power consumption in standby mode was about 300 mW.
