Computer Simulation And Experimental Investigation Of A Matrix Converter

Matrix converter is an "all silicon" power converter with an advanced circuit topology. It permits frequency conversion in a single-stage processing without the need of large reactive energy storage components, such as DC capacitor. It draws sinusoidal input currents and allows the input fundamental displacement factor to be set at unity or freely varied regardless of the load power factor. Besides these, it is capable of performing frequency conversion with sinusoidal output voltages and currents at the desired output frequency and allows bi-directional power flowAccording to the space vector modulation method of the equivalent structure of the AC-DC-AC conversion, the conversion relations of the matrix converter were deeply investigated. The AC-AC direct transformation control and the double-space-vector PWM scheme of the matrix converter were deduced and the modeling, sin~iu1ation and experiment of a three-phase matrix converter were implemented. Due to the lack of the true bi-directional switches at present, the combinations of IGBTs controlled by four-step current commutation algorithm were adopted in the simulation, which made the study very close to the reality. Combined with the advantages of matrix converter, AC-excited generation technique and vector control scheme, the stator flux-oriented vector control model of the Variable-Speed Constant-Frequency (VS CF) AC-excited generator fed by a matrix converter was developed. Simulation studies of the proposed power generation system were carried out. Combinations of IGBTs controlled by four-step current commutation algorithm, was implemented by the CPLD, which was also forecasted and validated by the simulation and experiment. The hardware of the DSP-based control system was constructed and the software was designed and written. Experiments of applying the matrix converter to induction motor drive were completed. The simulation and experiment results demonstrate the correctness and feasibility of this scheme.This thesis discusses principal issues of the matrix converter such as prime principle, control strategy, current commutation, its applications etc. By the theoretical analysis, computer simulation and experimental investigation, some valuable experiences and significant conclusions are given, which found the basis of the project for the further studies.