Regular-sampled harmonic elimination/minimisation PWM techniques

Recent developments are surveyed in regular-sampled pulse width modulation (PWM) techniques which allow harmonic minimization and also harmonic elimination to be generated online in real-time using a simple microprocessor software algorithm. It is shown how, with suitable modification, the conventional regular-sampled PWM techniques can be simply extended to allow harmonic-minimization and also harmonic-elimination PWM to be closely reproduced using simple algebraic equations. Using these optimal regular-sampling PWM techniques, it is possible to produce optimized PWM inverter drive, uniterruptible power supply, and static frequency converter performance, up to quasi-square-wave operation. All the detailed theory, mathematics, and equations needed to implement these new PWM strategies are presented, together with experimental results confirming the approach.