A New Control Scheme for an Hybrid Two-stage Matrix Converter with Improved Efficiency

Matrix converters have no boost capabilities and their output voltage amplitude is therefore reduced compared to back-to-back inverter topologies. Moreover, they are sensitive to grid voltage fluctuations and disturbances and the voltage transfer ratio is further reduced under such grid perturbations. The introduction of a H-bridge in the DC-link of the two-stage matrix converter results in a topology that allows to overcome these drawbacks by the means of an appropriate control. The present paper proposes a new control scheme that minimizes the losses and control complexity of the latter topology. This results in a converter that has higher voltage transfer ratio and similar energetic efficiency than the conventional two-stage matrix converter together with a low sensitivity to grid unbalances