Research on the Hybrid Pulse Width Modulation Strategy for Active-Neutral-Point-Clamped Three-Level Converter Based on IGCT

摘要

Active-neutral-point-clamped (ANPC) three-level converter based on IGCT can balance the loss of switching devices. Because of the wide range of the output frequency of the three-level converter, the variation range of the carrier ratio in the whole speed range is also large. Therefore, the converter often adopts hybrid pulse width modulation strategy to meet the control requirements in the low frequency. Moreover, the impulse current of the transient process between the two modulated modes must be limited to ensure the normal operation of the converter. The mathematical model of ANPC topology and asynchronous motor load is established in the paper, in order to analyze the causes of stator impulse current between varies PDSPWM modes. Finally, the PSIM simulation results are provided to verify the effectiveness of the equation and to draw conclusions.