Emulation of a small wind turbine system with a separately-excited DC machine

Abstract

A small wind turbine emulator based on a separately excited DC machine is described in this paper. Theexperimental rig consists of a PC, Lab Master I/O board, power electronics circuitry and a 3HP separately excitedDC motor which drives a synchronous generator. Varying aerodynamic power of the wind turbine due to furlingaction and its resulting dynamics are incorporated in the emulator with the use of a PC based wind turbine model.The shaft torque of the dc motor is determined from the armature current and parameters of the DC drive obtainedby experimentation. In order to reflect the inertia of a small wind turbine an inertia disk is designed and coupled tothe generator shaft and separately- excited DC motor. A digital PI controller is designed which makes sure that theactual rotational speed of the motor is tracking the theoretical rotational speed of the wind turbine rotor. Thesystem design, model used and experimental results of the small wind turbine emulator are presented in the paper.