Modulation and control scheme for current source inverter-fed induction motors
摘要
Compared with the voltage source inverter-fed (VSI-fed) induction motor drive, the current source inverter-fed (CSI-fed) induction motor (IM) drive can protect systems from overcurrent and short circuits and has a higher filtering characteristic. However, the generation method of switching signals for the CSI is different from that for the VSI, and the action modes of the switching tubes change with the sectors. In addition, due to the filtering capacitor parallel connected with the IM, the order of the AC-side system increases, which increases the complexity of the modulation and control schemes for the CSI-fed IM. In this paper, the vector composition and sector distribution formed by the switching states are analyzed. On this basis, SVPWM modulation without an additional hardware logic conversion circuit is proposed, and its implementation process is presented. Then, the control system, which contains the voltage proportional inner loop and the current proportional–integral outer loop, is designed for the CSI-fed IM, and the principle of parameters tuning is presented in detail. Finally, simulation models and experimental results are established, and the correctness of the modulation scheme implementation process and the effectiveness of the control system presented in this paper are verified.