Theoretical and experimental investigation on the stability of matrix converters

Matrix converters perform a direct coupling between two ac sources without the need for energy storage components. This characteristic, together with the presence of L-C input filters and the feedforward compensation of the input voltage variations, may determine unstable operation as the power delivered to the load exceeds a limit value. In this paper, a theoretical analysis of the stability of matrix converters is presented with the aim of predicting possible critical operating conditions. It is verified that all of the system parameters affect more or less the stability, including the delay introduced by the digital controller and the power losses. The theoretical analysis is supported by numerical simulations and experimental results carried out on a matrix converter prototype.