The Control Strategies Of Three-Lever Four Quadrant Pulse Rectifier

Pulse rectifier is one of the main components of the AC Drive System for the advantage of adjustable power factor, constant voltage and bidirectional power flow. Three-level Topology get more and more attention in large-capacity high-voltage power transform places because of its lower switching frequency and harmonic distortion rates, and smaller features.A three-level Neutral Point Clamping(NPC) rectifier was used as the research object. In this paper, structure and working principle of pulse rectifier are given, and gives a minute study on the Control Strategy include indirect current control, hysteresis current control, transient current control and predictive control. And furthermore the simulation Model for an application example is designed in Matlab/Simulink environment. The deeper theoretical research and simulation analysis of the three-lever diode-clamp pulse rectifier provide a theoretical basis for the physics experiments in the next step.Aiming at neutral point shift problem of three-level Neutral Point Clamping rectifier, an effective control scheme is presented. The author developed his own clues of thinking, viewpoints, and approaches that are based on the research of the relation between Intermediate capacity and the Secondary Harmonic Suppression.The simulation results show that the whole system can achieve close to unity power factor,the THD less than 2% and constant output voltage, the transient current control strategy offers good control effects and reliability.. The neutral point voltage control is fast and effective and the Three-level Topology can reduce the THD compared with the two-level Topology. So the designed control Strategy of the Three-level Topology Pulse rectifier have perfect comprehensive performances and suitable for rectification of AC Drive System.