Modeling and Simulation of Grid Connected Permanent Magnet Generator (PMG)-based Small Wind Energy Conversion Systems

Abstract

A small scale wind energy conversion system has tremendous diversity of use and operating conditions, and consequently is evolving rapidly along with the large scale wind energy conversion system for generation of electricity in either stand-alone or grid connected applications. In recent years, the grid connected small wind turbine industry is primarily dominated by the Permanent Magnet Generator (PMG) machines. The power conditioning systems for grid connection of the PMG-based system requires a rectifier, boost converter and a grid-tie inverter. Such system should be based on an appropriate control strategy to control the aerodynamic power during high wind speed, maximum power production, and maximum power flow to the grid at all operating conditions. This paper presents mathematical modeling and control strategy for the grid connected PMG-based small wind turbine systems. Furling control and expected dynamics are adopted with the wind turbine for aerodynamic power control, while the optimum speed of the PMG is followed to ensure maximum power production. A novel controller is derived from the optimum speed information that promise maximum power flow to the grid by controlling the boost converter output voltage and current through the duty cycle. It is found that the proposed modeling and control strategy is feasible and results are verified through simulation.

Energy Cost Estimation of Small Wind Power Systems—An Integrated Approach

“…The tip speed ratio is a function of wind speed v, rotor rotational angular speed ω and rotor radius : = (2) The performance coefficient is related to the tip speed ratio and the blade pitch angle . While the blade pitch angle does not change in a fixed pitch wind turbine, the relationship between and can be approximated by a quartic equation [5] as ( ) = 0.00044 − 0.012 + 0.097 − 0.2 + 0.11 (3) With (1) to (3), the annual mechanical energy production for the selected wind turbine can be calculated by (4). The availability factor [25] of 0.9 is an average value given by wind industry to account for loss of turbine availability due to icing and other unexpected shutdown events.…”

“…Separate models for characteristics and performance of SWPSs have been developed [2][3][4][5][6][7][8][9][10][11], to investigate certain aspects of energy costs for SWPSs. Studies on energy costs of SWPSs have been conducted based on these models.…”

Power reduction and resonance avoidance of Maglev vertical axis wind turbines using attractive type passive magnetic bearings

“…Low wind speeds tend to be found in areas around the equatorial regions. A wind speed of at least 5 m/s is needed for a typical horizontal axis wind turbine (HAWT) to operate and produce energy (Arifujjaman, 2011). Another issue is that these areas are subjected to unstable multi-directional wind which is the cause of making HAWT incompatible in these regions.…”