PMSG-Based Wind Energy Conversion Systems Integration Into DC Microgrids With a Novel Compact Converter

DC microgrids (DC-MGs) are recognized as an efficient alternative for common AC-MGs. DC-MGs need fewer power electronic converters since most of distributed generation (DG) units and electronic loads operate with DC voltage. The integration of DGs that generate AC voltage, such as wind energy conversion systems (WECSs) into DC-MGs, however, requires an AC-DC conversion unit to perform AC-DC conversion and galvanic isolation and to control the WECS. Typically, two separate cascaded converters are used to perform such functions, which increases the cost and size of DC-MGs. In this paper, an isolated single-stage AC-DC converter is proposed that is able to perform all the required function of a WECS AC-DC conversion unit, to overcome the drawbacks of the two-converter structure. First, the operation of the proposed converter and its features as a single unit are described. The operation of the WECS with the proposed converter is then studied. A design procedure for both the steady-state and dynamic operation of the converter is developed based on a mathematical model. Experimental results obtained from a scaled-down prototype converter are also presented to confirm the feasibility of the proposed converter as a single unit. The complete WECS operation is verified by the simulation results of the aerodynamic, mechanical, and electrical system models, using MATLAB/SIMULINK.