An adjustable sinusoidal PWM sampling process for AC drives

The paper presents a new sinusoidal PWM sampling process which can be adjusted to give some control over the generated waveform spectrum. It is shown how this feature allows the generation of waveforms with low harmonic distortion or selected low order harmonics to be suppressed. However, like established regular sampling techniques, the process is suitable for direct implementation in microprocessor based digital controllers. The process is compared against optimal and sub-optimal regular sampling methods and it is demonstrated that at low frequency ratios the process has superior performance to regular sampling and compares favourably with the published optimal techniques