一种改进的三电平逆变器SVPWM简化算法

摘要

Neutral point clamped three-level inverter has become one of hotspots of studies and application in the field of high-voltage and high-power inverter,but its corresponding conventional space vector pulse width modulation (SVPWM) algorithm requires complex and time consuming calculations.The existing SVPWM simplified algorithms were analyzed and proposed an improved strategy.The improved algorithm carries out the judgments of large sectors,calculation of dwelling times and switching sequences,output waveform modified of the corresponding two-level PWM inverter by detecting the three-phase instantaneous value of output reference voltage.The entire modulation process takes only simple four arithmetic operations and its steps clear and easy to implement.Simulation results validate the simplified algorithm.%中点钳位式三电平逆变器是目前高压大功率逆变领域研究和应用的热点之一,其相应的传统空间矢量脉宽调制(SVPWM)算法复杂度高,运算量大.分析了现有的SVPWM简化算法,提出了一种改进策略,通过输出参考电压的三相瞬时值进行大扇区判断、开关状态时间计算和对应的二电平PWM逆变器输出波形反修正,整个调制过程仅需进行简单的四则运算,步骤清晰易于实现.仿真结果证明了该算法的可行性.