| The concept of matrix converter has been raised for more than 30 years, in the modulation strategy, commutation mode,the switch device development, and other key technologies have made remarkable progress. However, in the practical application of matrix converter,because of the control strategy of matrix converter, voltage transfer ratio can not make more than 0.866 in AC motor. In order to increase the AC motor's speed range,find a suitable modulation strategy to improve the voltage transfer ratio of matrix converter is a hot topic in the current study. In additional, two-stage matrix converter has many good performances: simple control strategy,high system reliability,simple commutation mode.This paper introduces the circuit of matrix converter and compared the merit and shortcoming of different matrix converter circuit in detail; analyses several common control strategies of matrix converter and the characteristics of various control strategies; studies over modulation control strategy of matrix converter based on SVPWM; increases the voltage transfer ratio to 1.05 based on over modulation control strategy; introduces the control strategy of two-stage matrix converter and proposes an over modulation strategy for two-stage matrix converter to reduce the low harmonic. Over modulation control strategies for matrix converter and two-stage matrix converter are simulated by Matlab/Simulink.
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