STUDY AND CONTROL OF TWO LEVEL PWM RECTIFIER-SEVEN LEVEL NPC VOLTAGE SOURCE INVERTER CASCADE. APPLICATION TO PMSM SPEED CONTROL

摘要

In this paper, the authors present study on the stability problem of the input DC voltages of the seven levels NPC voltage source inverter (VSI). In the first part, they develop knowledge and a control model of this converter. Thus, they elaborate its working model without presumption on its control using DESIGN method associated to Petri nets. In the second part, the authors propose a PWM strategy, for this inverter, which uses six bipolar carriers. As application, we study the performances of the speed control of PMSM fed by this inverter. In this part, the authors use constant input DC voltages. In the last part of this paper, the authors study the stability problem of the input DC voltages source inverter. Thus, they study a cascade constituted by two-level PWM rectifier-filter-seven level NPC VSI. This study shows the effect of the stability problem of the DC voltages on the PMSM performances. To remedy to this problem, the authors propose a solution which uses a clamping bridge. The results obtained confirm the good performances of the proposed solution.