Emulation of Wind Power with a DC Machine to Provide Input to a Doubly-Fed Induction Machine

Abstract

The behavioral modeling of a separately excited direct current (DC) motor as a prime mover for a doubly-fed induction machine (DFIM) is studied in this thesis. The output torque of the DC motor is computed in the simulation under controlled parameters. The input to the DFIM, used as a doubly-fed induction generator (DFIG), is taken from the DC motor. In theory, the combination of the two machines can be used to emulate various wind patterns and their expected electrical returns for a given DFIM-based wind turbine. A Simulink model was created to appropriately emulate the operation of the DC machine. That model was then incorporated into an existing model of a DFIM. The resulting simulations are compared to system operating data to determine if machine speed is being correctly modeled. The speeds determined by the simulator accurately track those that are gathered from lab data. Operating speeds of the system were mapped to historical wind speeds in a geographical area. Output power of the DC motor for the different operating speeds was calculated and plotted. The data confirmed the theory of the proportionality of the rotational output power of a DC motor.