Large-signal model for the stability analysis of matrix converters

The interest in using the matrix converter (MC) for motor drive applications and energy conversion systems is steadily increasing due to its main advantage of performing a direct coupling between two three-phase alternating current sources without the need of an intermediate direct current bus. This characteristic, together with the presence of inductance-capacitance input filters and the feedforward compensation of the input voltage variations, might yield unstable operation in electrical drives. In this paper, a theoretical analysis of MCs based on a large-signal model is presented with the aim to show which parameters may affect the stability and to explain the reason of this phenomenon. The theoretical analysis is supported by several experimental tests carried out on an MC prototype.