Novel On-Line Step Pulse PWM Algorithm For Cascade Multilevel Inverters

For cascade multilevel inverters, the step pulse waveform PWM method is a typical solution in high-power applications. Since there exists a big problem of solving transcendent equations, which requires a long time computation, the off-line approach is commonly used in practice. In contrary, an on-line approach can present a more flexible solution for variable frequency and amplitude of output voltage and no large memory is needed. In this paper, an on-line step pulse PWM method, which is advantageous for its simple algorithm, capable for entire modulation range and generalized characteristics for any level inverter, is presented. The mathematical formulations and simulation results are presented