Sequencing of supplies of the matrix converter: Improvement of the start-up and MC interaction with the filter and clamp circuit

The matrix converter (MC) presents a promising topology that needs to overcome certain barriers (protection systems, durability, the development of converters for real applications, etc.) in order to gain a foothold in the market. This article focuses on MC hardware. In order to improve the switching speed of the MC and thus obtain signals with less harmonic distortion, the appropriate driver topology is selected. Inadequate driver control can lead to the destruction of the MC. Moreover, this converter is specially sensitive during start-up, as at that moment there are high overcurrents and overvoltages. With the aim of finding a solution for starting-up the MC, a circuit is presented which ensures a correct sequencing of supplies, thus avoiding a short-circuit between input phases. Furthermore, it detects overcurrent, connection/disconnection, and converter supply faults. Faults cause the circuit to protect the MC by switching off all the IGBT drivers without latency. Lastly, an analysis is made of the interaction that takes place during the start-up of the MC between the input filter, clamp circuit and the converter. A variation of the clamp circuit strategy is presented which minimizes the overcurrents that circulate through the converter. For all these reasons, it can be said that the techniques described in this article substantially improve the MC start-up cycle, representing a step forward towards the development of reliable matrix converters for real applications.