Unidirectional step-up ultra sparse matrix converter for 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. In this paper the unidirectional step-up ultra sparse matrix converter (SUMC) is proposed as direct competitor to the widely used voltage link back-to-back converter (VLB2B) for integration of wind energy resources to the microgrid. The principles of operation of the SUMC are established. A carrier based modulation scheme is applied to control the converter. It is shown that this modulation method is capable of providing sinusoidal output currents. A cascade control scheme is employed for the control of the input currents and output voltages of the converter. The common mode voltage for the converter derived from this carrier based modulation scheme is analyzed and shown to be less than the amplitude of the phase voltage. Simulation results are used to validate the suitability of the converter for integration of wind energy resources to the microgrid.