Speed Sensorless Vector Control Three-level Inverter

The technology of frequency inversion and the theory of speed sensorless vector control of diode Netrual-Point-Clamp(NPC) three-level inverter are introduced in this paper. The technology of three-level inverter is researched deeply. The principle of three-level inverter is introduced, and the three-level voltage vector control method is analyzed in detail. The formulas about PWM pulse and the order of switches action are also presented.A simple and effective mathematic model of three-level inverter and introduction machine is built by analyzing inverter and introduction machine as a whole. Thus ,an effective tool is provide for the research of the three-level inverter and introduction motor varied a new scheme.The theory of speed sensorless vector control is studied profoundly. A new method of speed sensorless vector control is introduced in this paper. It gives the method of how to realize the sampling in DSP. A new method of identifying motor equivalent circuit parameters and the method of MRAS in speed estimator of sensorless vector control system is introduced in this paper.The main-circuit of three-level inverter, the protection and drive technology about IGBT and the control circuits based on DSP series microprocessor are designed. A set of low power three-level inverter is accomplished for the experiments.Software design and how to realize the three-level speed sensorless vector control method are described. The problem during the design and the experimental results of this equipment are analyzed.The study and the conclusion of this study have the important meanings to the project of sensorless vector control based in DSP.