Analytical calculation of semiconductor current stresses and control of step-up matrix converter for the integration of wind energy resources to microgrids

The voltage link back-to-back converter (VLB2B) is widely employed for integration of wind energy resources to the microgrid. However the dc-link capacitor of the VLB2B reduces the life span of the converter and also makes the entire converter bulky. Conventional matrix converters have been suggested as possible replacement for the VLB2B converter but the lack of voltage boost ability makes them unsuitable for grid integration applications. The unidirectional step-up ultra sparse matrix converter (SUMC) has been proposed as direct competitor to the widely used voltage link back-to-back converter (VLB2B) for integration of wind energy resources to the microgrid. In this paper, a new cascade control scheme is employed for the control of the input currents and output voltages of the converter. The designed controller is capable of operating the converter in islanding mode without the need to change the structure of the controller. To facilitate the design of the converter, analytical calculations of the current stresses on various semiconductor components are established. Simulation results are used to validate the accuracy of the analytical expressions and the effectiveness of the designed controller.