A Duty Cycle Space Vector Modulation Strategy for a Three-to-Five Phase Direct Matrix Converter

The duty cycle space vector (DCSV) modulation strategy is of universal significance, and the method can be utilized for different modulation approaches. In this paper, the vectors of input voltages and currents are equivalently represented by a complex two-dimensional space vector, and the vectors of output voltages and currents are equivalently represented by two two-dimensional space vectors. Then, input-output relationships in both the d1-q1 space and the d3-q3 space are obtained. Because the desired output voltages are only mapped onto a reference voltage space vector in the d1-q1 space, the reference in the d3-q3 space is regarded as zero, in order to reduce harmonics of output voltages to the greatest extent. Then, the duty cycle space vector modulation strategy of the three-to-five phase direct matrix converter (DMC) is deduced. Considering the influence of the zero vector on system performance, the duty cycles are decomposed and recomposed to obtain the space vector pulse width modulation (SVPWM) strategy based on the duty cycle space vector. Finally, the accuracy and feasibility of the theory are verified through experiments.