Thermal analysis of matrix and Back-To-Back converters for series-connected wind turbines

The efficiency and thermal performance of AC-AC converters in series-connected DC wind turbines is the object of this paper. The considered conversion system is composed of a permanent magnet synchronous generator, an AC-AC converter, a high frequency transformer and a diode bridge rectifier. Two different converter topologies are compared: the Back-to-Back converter and matrix converter, in terms of efficiency and thermal performance. The modulations used for each converter are presented. The control for each converter is described as well as the method used for loss and temperature calculations. The results show that the matrix converter is more efficient than the back-to-back converter, however in terms of thermal performance and temperature fluctuation, the back-to-back is slightly superior.