Space vector modulation for a three-level NPC ac-dc converter system: An experimental investigation

Industrial and traction drives (used in automobile and electric locomotives) using induction motor, require a good control over torque and speed, reversible and regenerative speed control operation. Hence the drive topology requires both ac to dc conversion and dc to ac conversion system. In this paper, a three-level utility friendly the front-end neutral point clamped (NPC) converter system having four quadrant capabilities is presented. The current control technique based on space vector modulation (SVM) has been applied to the ac-dc converter system, for dc-link voltage and input current control. The input current remains in phase with the input voltage keeping dc-link voltage constant. The experimental investigation has been realized with a PC based control, employing National Instruments (NI) data acquisition system (PCI-MIO16-E-4) for control of the converter. Simulation and laboratory prototype test results demonstrate the validity of the proposed current control method.