【摘要】 四开关升降压(four-switch buck-boost, FSBB)变换器具有宽范围电压输入的优势。由于开关频率高，变换器工作在降压(Buck)模式或者升压(Boost)模式下效率最高，但是在输入电压改变时，两种模式之间的切换会产生转换盲区。文中采用脉宽调制(pulse width modulation, PWM)技术，对传统的两模式控制方法加以改进，设计加入了第三种升降压(Buck-Boost)模式进行平滑过渡。实验结果表明，瞬时改变输入电压时，输出电压波形波动小，证明新的控制方法有效地解决了转换盲区问题，保证了输出电压的稳定。更多还原

【Abstract】 The four-switch buck-boost converter has the advantage of wide range of voltage input.Due to the high frequency of the switch, the converter is most efficient in Buck or Boost mode, but when the input voltage changes the switching between the two modes will produce the conversion blind area. In this paper, the traditional two-mode control method is improved by pulse width modulation(PWM) technology, and the third Buck-Boost mode is added to smooth the excessive.The experimental results show that the output voltage waveform fluctuates is less when the input voltage is changed transiently, which proves that the new control method effectively solves the conversion blind area problem and ensures the stability of the output voltage.更多还原