REN Xiang， WANG Yaoqi， WANG Xiaopeng
（School of Electronic and Information Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China）
Abstract： For a conventional high-power active power factor correction (APFC) boost converter, its output capacitor needs to be precharged, which means that two power switches of the main circuit and the control circuit are needed to be respectively turned on and turned off in a fixed order. After the main circuit switch is turned on, it is necessary to wait for precharging before turning on the control circuit power switch. Once an inadvertent operation is performed, an overcurrent phenomenon from the output capacitor will occur. In this study, the buck circuit is used as the pre-stage snubber circuit, which can directly supply power to the circuit without precharging the output capacitor. As a result, potential safety hazard caused by the overcurrent due to the capacitor and the charging maloperation during the start-up stage can be avoided. Theoretical analysis and simulation experiment show that the DC boost converter with buck buffer can maintain the peak value of the main circuit within the safe range when the device boot does not precharge the output capacitor, and thus the safety and stable operation of the DC boost converter are ensured.
Key words： active power factor correction (APFC); boost converter; precharging; power switch; overcurrent; buck buffer
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带buck缓冲的直流升压变换器
任相， 王耀琦， 王小鹏
（兰州交通大学 电子与信息工程学院， 甘肃 兰州 730070）
摘要:常规的大功率有源功率因数修正（Active power factor correction, APFC）升压变换中对输出电容需要进行预充电来避免过流现象， 因此主电路和控制电路的电源开关需按固定顺序分别闭合和断开， 在闭合主电路开关后需要等待预充电， 最后才闭合控制电路电源开关， 一旦操作过程中出现误操作， 输出电容就会产生过流现象。 本文采用buck电路作为前级缓冲电路， 无需对输出电容进行预充电就可以直接对电路供电， 从而避免电容与充电误操作带来的启动阶段电路过流引起的安全隐患。 对带buck缓冲的直流升压变换器模型进行理论分析和仿真实验可知， 带buck缓冲的直流升压变换器在不对输出电容预充电的情况下， 可以使设备启动时主电路电流峰值不超出安全范围， 从而确保直流升压变换器安全稳定的工作。
关键词:有源功率因数校正； 升压变换； 预充电； 电源开关； 过流； buck缓冲
引用格式：REN Xiang， WANG Yaoqi， WANG Xiaopeng. DC boost converter with buck buffer. Journal of Measurement Science and Instrumentation, 2021, 12（3）： 340-346. DOI： 10．3969／j．issn．1674-8042．2021．03．012
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