Analytical and numerical analysis of dead-time distortion in power inverters

The analytical spectrum of a pulse width modulated signal with dead-times is derived in this paper. The results are valid for any bounded, band limited signal. The harmonic content of the output voltage is computed by dividing the PWM signal in three components: a 50% duty cycle square-wave, a symmetrical, time-varying duty cycle square wave, and a pulse train that accounts for the dead-time. Specific expressions are obtained for simple modulating signals. Some numerical examples are included for comparison with theoretical results.