Julien Hobraiche

A New PWM Strategy to Reduce the Inverter Input Current Ripples

This paper deals with an innovating pulsewidth modulation (PWM) strategy allowing reduction of the DC input current ripples in classical operating area of adjustable-speed drives, and also maintaining a good quality of AC current waveforms and limited switching losses in the inverter. Thus, such a strategy is an interesting solution within embedded systems. Theoretical principles of the proposed method are introduced. Then, simulation results highlight the benefits of this algorithm compared to classical PWM control. Finally, a DSP-base implementation has been performed, and effectiveness of this strategy is confirmed by experiments for a starter-generator application.

A Direct Digital Technique Implementation of General Discontinuous Pulse Width Modulation Strategy

This paper presents direct digital technique-generalized discontinuous pulse width modulation (PWM) - a new implementation method for an optimal discontinuous PWM (DPWM) in terms of switching losses of the inverter on an embedded system. At each sampling period, an optimal choice is done in order to clamp one of the three half-bridges. Its advantages compared to classic ones (DPWM) are as follows: needless to know the load power factor, operational under steady-state and dynamic operating conditions, and low computation time. The proposed algorithm is then verified by simulation. Experimental results, based on a resistance-inductance load and a starter-generator application, are provided to show its effectiveness.