一种用于三电平逆变器的双模式过调制策略

One strategy of two-model over modulation for three-level inverter

为了提高直流母线电压利用率及实现线性调制到过调制最大输出(六阶梯波)的平滑过渡,研究了一种快速计算过调制中控制角的双模式过调制算法,该算法简单、有效,程序执行时间短,能够使系统的调制范围由线性调制区的最大范围(SVPWM)0～90.7%扩展到0～100%,并搭建中点箝位型三电平逆变器实验平台,对该双模式控制策略下的有效性进行了验证。实验结果表明,输出电压明显提高,可以满足多数高转矩输出或较低电压场合的需求,该策略具有实用性的参考价值。

Abstract：In order to improve the direct current bus voltage utilization and implement the smooth transi- tion from the linear modulation to the maximum output（six-step stage wave） in overmodulation operation, a quick two-mode algorithm of calculating control angle was researched. It simply and effectively imple- ment the scope of modulation range extended from the maximum linear region（ SVPWM）0 - 90.7% to 0 100% and shorten the time of program operating. At last, neutral-point clamped（NPC） three-level in- verter experimental prototype was established, and some experimental results were given to validate the strategy. The experimental results show that the voltage output increases clearly, outputing high torque or running under lower voltage condition can be satisfied, and the modulation approach has practical refer- ence value.