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

Abstract

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.

Wind turbine emulator control improvement using nonlinear PI controller for wind energy conversion system: Design and real‐time implementation

“…The following equation expresses the mechanical power captured by the WT: 17 $$$$ {P}_m=\frac{1}{2}\rho A{v}^3{C}_p\left(\lambda, \beta \right), $$$$ where $$$ \rho $$$ is density of air ($$$ \mathrm{kg}/{\mathrm{m}}^3 $$$), $$$ A=\pi {R}^2 $$$ is area that is swept by the blades of the turbine ($$$ {\mathrm{m}}^2 $$$), $$$ R $$$ is the ray of the blade (m), $$$ {C}_p\left(\lambda, \beta \right) $$$ is power coefficient, and $$$ v $$$ is wind speed (m/s).…”

“…[8][9][10] Variable speed WECS make use of a variety of generator types, such as doubly fed and squirrel-cage induction generators, [11][12][13][14][15] permanent-magnet, and wound-rotor synchronous generators (WRSG). [16][17][18][19] The use of the gearless permanent magnet synchronous generator for WECS has become more important due to its low losses, minimal cost of maintenance, high efficiency, and self-excitation. 20 The DC motor drive is frequently used for WTE, 21 compared to the permanent magnet synchronous motor drive, 22 or squirrel cage induction motor drive, 23 because of the simplicity of its implementation in the control.…”

“…The latter is a better choice than fixed speed because of its better control performance, lower acoustic noise and mechanical stresses, and higher efficiency and power quality, making it the most suitable for wind power applications 8‐10 . Variable speed WECS make use of a variety of generator types, such as doubly fed and squirrel‐cage induction generators, 11‐15 permanent‐magnet, and wound‐rotor synchronous generators (WRSG) 16‐19 . The use of the gearless permanent magnet synchronous generator for WECS has become more important due to its low losses, minimal cost of maintenance, high efficiency, and self‐excitation 20 .…”

Duty Cycle-Rotor Angular Speed Reverse Acting Relationship Steady State Analysis Based on a PMSG d–q Transform Modeling

“…Now, based on the assumptions related to the model and according to [34,35], first principles can be utilized to obtain the corresponding state-space representation, as is shown in Equations ( 2) and (3).…”

Three-phase AC-DC Converter for Direct-drive PMSG-based Wind Energy Conversion System

“…Reference [9] proposes a bridgeless boost rectifier for WECS, which requires connections from all six terminals of the PMSG and six switches for rectification. Reference [18] proposes a compact AC-DC converter, which has a larger number of switches and uses an isolation transformer, thus increasing the complexity of control and cost. Reference [10] presents a three-phase AC-DC converter using space vector modulation, but it requires current sensors for power factor correction (PFC).…”