Study On Matrix Converter Used For Variable Speed Constant Frequency Supply System

Matrix Converter is a power converter based on AC-AC direct conversion. More and more attention is paid to Matrix Converter because of its advantages, such as omitting the DC part, obtaining unit power factor, getting sinusoidal input currents and output voltages and easy to realize bidirectional flow of energy.This thesis first briefly introduced the Matrix Converter's structure and the mathematical model and the operation principle. Then, the second part introduced establishing the matrix converter system's simulation model with the help of Matlab software. The third part analysis space vector modulation of Matrix Converter, and obtained the electric relations between the input and output voltage. Based on analysis above, this thesis realized the output voltage closed-loop control. The closed-loop control is by the revision of output voltage's quadrature-direct axis component. The output voltage amplitude and the angle could be adjusted at the same time. This article also analyzed the instantaneous values of input line-to-line voltages control strategy. And inferred the output voltage and input current synthesis formula. Moreover, this thesis has simplify the composition rule of duty ratios,and summarizes the universal expression of duty ratios composition.This paper proposed a new variable to expression extremal input voltages polar by analyzing the source key theory, and the method to detect the sector of output voltages is new.Finally, this thesis introduces the hardware and software design of the digital control system of Matrix Converter. A series of experiments have been made and the experiment results are obtained on the prototypes, which prove that the theories and analysis are correct.