Influence of a modulation reference with continuous component in a converter-machine set

Pulse Width Modulation (PWM) new techniques give better inverter output voltages. So, a potential difference is introduced between the inverter artificial reference point O and the machine neutral point N. This paper proposes a new parameter for the PWM modelling, to represent this O-N voltage variation in the inverter control. This potential difference imposes a system decomposition on the converter-machine set: each reference point is associated to own reference frame. Firstly, the standard case VNO=0 is studied by the analysis tools. Then, the influence of a VNO continuous value voltage is shown on the voltage harmonic spectrum and on the machine behaviour. Lastly, a study of PWM with third harmonic injection is realized and shows interest of the new PWM modelling for modern modulations. (orig.)