Synchronization of output voltage waveforms in three-phase inverters for induction motor drives

A novel method of direct synchronous pulsewidth modulation (PWM) for three-phase voltage source inverters is applied in this paper to basic continuous and discontinuous schemes of PWM. It is based on a new strategy and scheme of feedforward PWM, providing synchronization of voltage waveforms and linear voltage control during the whole range including the zone of overmodulation. Algebraic and trigonometric versions of the method proposed, based on vector approach for determination of the pulse patterns, are analyzed and compared. Examples of determination of the basic parameters of the output voltage of the inverter are presented. Simulations give the behavior of the analyzed methods and techniques. Simplicity and physical clarity are characterizing the proposed PWM method.