中文摘要：

基于一种利用Boost三电平（three—level，TL）变换器平衡输出侧中点电位的方法，对变换器的工作模式进行深入分析。该方法在不改变变换器电压输入一输出关系的前提下，通过调节两开关信号问的相差控制输出侧两电容的充放电时间，从而平衡中点电位。通过对工作模式的分析，推导出新的变换器不同工作模式间临界升压电感计算公式。公式表明，临界升压电感不仅与开关信号占空比有关，且与两信号间的相差有关。通过Matlab／Simulink软件进行仿真，并利用基于DSP（TMS320F2812）的硬件系统进行了实验验证。仿真与实验结果证明了理论分析的正确性。

英文摘要：

Different operating modes were analyzed for the Boost three-level （TL） converter which was used for balancing the neutral-point potential. The NP potential was balanced by adjusting the phase-delay between the two switch-signals of the Boost TL converter without changing the boosting feature of the converter, Which was named phase-delay control. The formulas of critical Boost inductances between different operating modes were deduced according to the analysis on operating modes. These formulas indicated that the critical inductance is not only related to duty ratio but also related to the phase-delay between the two switch-signals of the Boost TL converter. The prototype was simulated by using the software of Matlab/Simulink and tested by the hardware based on DSP （TMS320F2812）. The correctness of the analysis was verified by the simulated and experimental results.