Sliding mode direct control of matrix converters

Abstract

The direct control problem of matrix converters with input inductive capacitive (LC) filter using a new approach based on the sliding mode control technique is solved. This approach allows the design of the controller considering the converter and the dynamics of its associated LC filter. Together with the space vector representation technique, sliding mode allows the precise determination of switching times between the bi-directional switches, thus being appropriate to the nonlinear ON/OFF behaviour of the matrix converter power semiconductors. As the switching occurs just in time, this technique guarantees fast response times and precise control actions, ensuring that the output voltages and the input currents track their references and making input power factor regulation independent of the input filter parameters. This feature has special interest in applications requiring unity input power factor, when feeding AC drives, or applications needing variable and accurate input power factor regulation, usually related to power quality enhancement. The designed sliding mode controllers are tested and the obtained simulation and experimental results show that they ensure the direct control of matrix converters over a wide range of output frequencies, guaranteeing a leading or lagging input power factor regulation.