关键词: 三电平二极管钳位型(NPC)牵引变流器, 矢量控制, 中性点电压, 全阶磁链状态观测器, 死区补偿

Abstract: Aiming at the application of three-level neutral point clamped (NPC) traction converter in sensorless vector control of induction motor, based on the space vector modulation algorithm (SVPWM), the problem of neutral point voltage balance was solved by introducing different threshold values of neutral point voltage offset, and using the method of hysteresis control and active control for vector action time under different thresholds. Based on the speed information obtained by the full order flux observer, the current inner loop control architecture in vector control was optimized. On the basis of analyzing the influence of dead time, a real-time dead time compensation method based on three-level SVPWM control was proposed, which has less code, simple implementation and easy integration. The applicability and effectiveness of the control strategy were verified by simulation and motor driving test.

Key words: three-level neutral point clamped (NPC) traction converter, vector control, neutral point voltage, full order flux observer, dead time compensation