Matrix converter modulation for series-connected wind turbines with high frequency link

In this paper a matrix converter modulation adapted for the wind energy conversion system of series-connected turbines is presented. The considered conversion system is composed of a permanent magnet synchronous generator, a matrix converter, a high frequency transformer and a diode bridge rectifier for the AC-DC conversion. This conversion system topology allows for a modification, introduced in this paper, of the indirect space vector modulation that increases the current ratio of the matrix converter and thus enhances its advantage for this wind park configuration. The modulation can be further modified into a square wave modulation for high frequency operation of the transformer. An efficiency analysis of the suggested modulation and its high frequency version is performed. Also some attention is given to the flux balance issue in the transformer and a possible solution for a modulation yielding balanced flux is given.