Evaluation of the input current quality by three different modulation strategies for SVM controlled matrix converters with input voltage unbalance

A new input current modulation strategy for a matrix power converter is presented. The performance of the new strategy during input voltage unbalance is compared to two other strategies. The difference of the three modulations only concerns the detection of the reference angle for the input current vector. The input current quality is evaluated using four different criteria. It is concluded that depending upon the modulation strategy, the distortion of the input current may appear either as a series of positive sequence harmonics or a negative sequence fundamental component or a positive and a negative series of harmonic components with reduced amplitudes. Good accordance is found between the analytical solutions and numerical simulations.