Modeling and control of variable speed wind turbine using laboratory simulator

Abstract

An important challenge associated with wind power is the unpredictable nature of the wind. As wind power forecasting is usually based on the relationship between wind speeds and wind power, wind farm data is a critical prerequisite for wind speed prediction, meanwhile it plays an important role on the reliability and safety of the grids. For development of new controls, converter topologies, modulation methods, and maximum power extraction algorithms for wind energy conversion systems, the provision of a controlled test environment showing dynamic and steady state characteristics of wind turbines is desired. In this paper, a small scale wind turbine experimental laboratory model based on separately excited dc-shunt motor and permanent magnet synchronous generator (PMSG) is proposed, which reproduces the static and dynamic characteristics of the wind turbine without any wind environment. A programmable wind speed model is established that can satisfactorily simulate the spatial effect of the wind behavior, including gust change, ramp variations, and noise effect. The dynamics of the simulator is studied using the drive train model of the armature controlled dc shunt motor. A microcontroller along with high frequency buck converter has been used for acceleration and deceleration of the dc motor. It is shown through the frequency response characteristics that the simulator model approximates the wind turbine model dynamics. Simulation and experimental results illustrate that the speed of the motor changes with variation in the applied terminal voltage, like in the real wind turbine where the turbine speed changes according to the wind speed. Simulation results are obtained through PSCAD/EMTDC simulation software and experimental results are obtained through the programmable microcontroller used with the DC-motor-PMSG set.