Single-stage Matrix Converter And Sparse Matrix Converter Is A Comparative Study

Matrix converter is considered as an "all silicon" power converter with an advanced circuit topology. It permits frequency conversion in a single-stage processing without large reactive energy storage components. 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 flow. The paper analyses the electric circuit composition, the mathematics foundation, the principle of work, and the switching commutation question of the one-stage matrix converter. Then two of the switch sates of a three-phase to three-phase matrix converter, based on notation, are introduced, which are called MDCM and SVM. Under the Space Vector Modulation scheme, there is a serious problem brought by the multi-step commutation, the multi-step commutation made the output voltage distorted, and the output voltage error is calculated, then an easy SVM scheme is proposed to compensate the output voltage error by correcting the duty time of the vector, with minimum output current harmonics.Traditional One-stage Matrix Converter has its obvious advantages such as powerful controllability, however, it can not be widely used in industry because of too many switch numbers, complicated structure, commutation problem, low voltage transformation ratio and complicated PWM method, and so on. So this paper details a novel matrix topology—Sparse Matrix Converter, which has the same advantages of traditional One-stage Matrix Converter such as: four quadrants operation; no DC capacitor and high quality input/output waveforms. Then the electric circuit composition and basic theories of Sparse Matrix Converter such as controlling method, the zero current commutation are presented and analysed in detail.The simulation models and waveforms based on Matlab/Simulink of One-stage Matrix Converter and Sparse Matrix Converter are both provided. The simulation results demonstrate the feasibility and reliability of the two converters and their modulation strategies. It is shown that the topologies are available, and performance of matrix converter is excellent. The simulation models are good tools for the modulation and beneficial to Matrix Converter's application.Based on the simulation results, traditional One-stage Matrix Converter and Sparse Matrix Converter are comparatively researched. Besides their electric circuit composition and controlling methods, the superiorities of Sparse Matrix Converter to One-stage Matrix Converter are presented: the number of switches can be reduced; the switches at the line side can be turned on and turned off at zero current, and no complex commutation technology and modulation strategy are needed. So there is an excellent develop foreground for Sparse Matrix Converter.