A Predictive Current Control Scheme for a Hybrid AC/AC Direct Power Converter

The Hybrid ac/ac Direct Power Converter (HDPC) has the advantage of improved voltage transfer ratio and higher robustness against supply voltage unbalances over the Conventional Matrix Converters (CMC). The HDPC also has the inherent advantages of the CMC such as: adjustable input power factor, sinusoidal supply currents and no bulky energy storage elements which reduce the life time of the converter. This paper proposed a predictive current controller scheme for a HDPC based on 2-stage matrix converter providing unity voltage transfer ratios; even in the case the supply voltage is highly unbalanced. The proposed predictive current controller is simple in digital implementation, provides higher bandwidth control, requires no additional circuitry and maintains a constant switching frequency which allows synchronizing the switching of the HDPC for sinusoidal supply currents.