Development of a test-rig for large scale wind turbine emulation

This research describes the development of a test-rig for observing the behavior of a large wind turbine system and investigates the design of power electronics and controller performances in a laboratory environment. The test-rig consists of a PC, Lab Master I/O board, power electronics circuitry and a 3HP separately-excited DC motor which drives a wound rotor induction generator with the rotor windings short circuited. A PC based wind turbine model is employed to simulate the wind turbine behavior where the power coefficient is a function of the pitch angle and tip-speed ratio. A velocity digital PI controller algorithm is adopted for the wind turbine controller to ensure the theoretical rotational speed of a wind turbine rotor by the separately-excited DC motor. The surge current at the motor armature is controlled through algorithm thus avoids any external current limiting circuitry. The system design, model used and preliminary experimental results of the wind turbine test-rig for a wide range of wind speed are presented in the paper.