Study on Varying-Step Commutation Strategy of Matrix Converter

Aiming at safe commutation and improving quality of output waveform, the paper presents a new varying-step safe commutation strategy of matrix converter by analyzing the character of traditional four-step commutation and improved four-step commutation strategy. On the basis of input-voltage-based commutation this new strategy synthetically considers the magnitude of input voltage and output current direction and accordingly distinguishes the safe partition and the unsafe partition. Then different commutation strategies are adopted in different partition which improving the reliability of commutation and decreasing the commutation time to improve the quality of output waveform. Finally, the( ) experiment results demonstrate the availability and reliability of the presented commutation strategy. Thereby, the open-circuit or short-circuit faulty caused by abnormal commutation can be eliminated. The output waveform can be improved because the commutation time can be decreased by 2/3 compared to the traditional four-step commutation strategy.