针对传统Buck变换器存在响应速度慢、过冲大、稳定性差等问题,提出了一种具有宽输入输出电流模式自适应导通时间(current mode adaptive on time,CM-AOT)控制方法以提升Buck变换器的工作性能.在研究中,补偿电路和一种新型的TON发生器可...针对传统Buck变换器存在响应速度慢、过冲大、稳定性差等问题,提出了一种具有宽输入输出电流模式自适应导通时间(current mode adaptive on time,CM-AOT)控制方法以提升Buck变换器的工作性能.在研究中,补偿电路和一种新型的TON发生器可以通过自然增减负载升压或降压瞬态中的开启时间来改善瞬态性能.转换器在稳态下呈伪恒定频率状态,并且频率不会随输入和输出的变化而变化.由于TON的变化仅发生在瞬态区间,因此不会影响COT控件的小信号特性.电路理论分析与仿真结果表明,此新型控制方法可显著提升开关响应速度,有效降低电压过冲,且具有较宽的输入输出,可适用于多种实际应用场景.展开更多
The adapted DC-DC converters should be smaller in size and have a small output current ripple to meet the increasing demand for low voltages with high performance and high density micro processors for several microele...The adapted DC-DC converters should be smaller in size and have a small output current ripple to meet the increasing demand for low voltages with high performance and high density micro processors for several microelectronic load applications. This paper proposes a DC-DC converter using variable on-time and variable switching frequency control enhanced constant ripple current control and reduced magnetic components. The proposed converter is realized by making the turn-offtime proportional to the on-time of the converter, according to the input and output voltage, thereby reducing the corresponding current ripple on output voltage in the continuous conduction mode. A Buck DC-DC converter using the proposed control strategy is analyzed in detail, along with some experimental results to show the performance and effectiveness of this converter.展开更多
The traffic-induced vibrations of the new CCTV Headquarters building are studied stages. In the first stage when the through experiments in two 30th floor of the northwest tower and the 38th floor of the southeast tow...The traffic-induced vibrations of the new CCTV Headquarters building are studied stages. In the first stage when the through experiments in two 30th floor of the northwest tower and the 38th floor of the southeast tower were finished, the traffic flows on the roads surrounding the building were investigated, and 27 setups of accelerations were measured at the roadside, on the pile cap and on the 9th floor. In the second stage when the whole steel structure was completed, l 5 setups of accelerations were measured at the roadside, on the pile cap and on the 37th and the 48th floors. The accelerations of the building under different traffic flows, in different positions are analyzed in both time domain and frequency domain. The damping ratios are estimated by the upgraded half-power bandwidth method.展开更多
文摘针对传统Buck变换器存在响应速度慢、过冲大、稳定性差等问题,提出了一种具有宽输入输出电流模式自适应导通时间(current mode adaptive on time,CM-AOT)控制方法以提升Buck变换器的工作性能.在研究中,补偿电路和一种新型的TON发生器可以通过自然增减负载升压或降压瞬态中的开启时间来改善瞬态性能.转换器在稳态下呈伪恒定频率状态,并且频率不会随输入和输出的变化而变化.由于TON的变化仅发生在瞬态区间,因此不会影响COT控件的小信号特性.电路理论分析与仿真结果表明,此新型控制方法可显著提升开关响应速度,有效降低电压过冲,且具有较宽的输入输出,可适用于多种实际应用场景.
文摘The adapted DC-DC converters should be smaller in size and have a small output current ripple to meet the increasing demand for low voltages with high performance and high density micro processors for several microelectronic load applications. This paper proposes a DC-DC converter using variable on-time and variable switching frequency control enhanced constant ripple current control and reduced magnetic components. The proposed converter is realized by making the turn-offtime proportional to the on-time of the converter, according to the input and output voltage, thereby reducing the corresponding current ripple on output voltage in the continuous conduction mode. A Buck DC-DC converter using the proposed control strategy is analyzed in detail, along with some experimental results to show the performance and effectiveness of this converter.
基金The study is sponsored by the National Natural Science Foundation of China （No. 50538010） and the Flander （Belgium）-China Bilateral Project （,No. BIL 07/07）.
文摘The traffic-induced vibrations of the new CCTV Headquarters building are studied stages. In the first stage when the through experiments in two 30th floor of the northwest tower and the 38th floor of the southeast tower were finished, the traffic flows on the roads surrounding the building were investigated, and 27 setups of accelerations were measured at the roadside, on the pile cap and on the 9th floor. In the second stage when the whole steel structure was completed, l 5 setups of accelerations were measured at the roadside, on the pile cap and on the 37th and the 48th floors. The accelerations of the building under different traffic flows, in different positions are analyzed in both time domain and frequency domain. The damping ratios are estimated by the upgraded half-power bandwidth method.
