Modulation Strategy Based on Mathematical Construction for Matrix Converter Extending the Input Reactive Power Range

In this paper, a modulation strategy based on mathematical construction is proposed to extend the input reactive power range for the three-phase matrix converter, which offers clear physical meanings and less computational efforts. This strategy is developed based on the construction of the modulation matrix composed by the sum of several matrices, one of which is used to generate the required output voltage. The others are intended to provide more degrees of freedom for control such that the matrix converter can produce the input reactive power as much as possible. In the framework of mathematical construction method, an optimization problem for the maximum input reactive power is formulated, whose analytical solution is difficult to obtain. Usually, optimization problem can be solved by using some numerical methods, but lots of time will be consumed. Therefore, a suboptimal method is presented to mitigate the computational burden. Besides, the proposed strategy is compared with the optimum-amplitude and indirect SVM methods, in terms of the maximum input reactive power for different operating conditions. It is shown that the proposed method can obtain the maximum input reactive power over most situations. Finally, the correctness of the proposed method is confirmed by simulation and experimental results.