Open Access

Jannik Maier, Philipp Czerwenka, Eckhard HennigORCiD, Ertuğrul SönmezORCiD, Gernot SchullerusORCiD

• This paper proposes a novel modulation adaptation method for a three-level converter using an asynchronous deltasigma modulator (ADSM) to reduce switching losses. Asynchronous delta-sigma modulators can reduce the average switching frequency compared to pulse width modulation (PWM) while offering superior total harmonic distortion (THD) performance due to their noise shaping capabilities. In contrast to fixed switching frequency PWM, the switching frequency of an asynchronous delta-sigma modulator depends on the instantaneous input signal. Therefore, the input signal waveform directly determines the switching frequency of the modulator. The proposed adaptation method uses two different input signal waveforms to reduce switching losses by decreasing the average switching frequency, considering the asynchronous delta-sigma properties. The input signal waveform is modified through linear interpolation by the proposed adaptation method compared to conventional input waveforms. The validation of the modulation adaptation method is confirmed by calculations, simulations, and measurements.