Analysis and implementation of a grey-noise PWM technique based on voltage space vectors

The grey noise pulse width modulation (GNPWM) technique for three-phase, voltage-controlled inverters is described. It is shown that the GNPWM combines the best features of the deterministic space-vector PWM and the random PWM techniques. The GNPWM technique is characterized by: the highest DC/AC voltage conversion; high-quality output current at a low switching frequency of the inverter; varying switching patterns and spread, grey-noise, harmonic spectra of the output voltage and current, beneficial for the noise/vibration characteristics of a drive system supplied from the inverter; and simplicity of the hardware implementation using an integrated microcontroller system. Theoretical background, simulations, and experimental results are presented.<>