Wind turbine power generation emulation via doubly fed induction generator control

Abstract

In this thesis, we emulate a Wind Turbine Generator by driving a Doubly Fed Induction Generator (DFIG) via a DC motor with variable input torque capability. The two circuits of concern are the DFIG and Supply-side circuits. They are electrically coupled with back-to-back Space Vector Modulators (SVMs) that are coupled through a DC Link consisting of a capacitor bank. The SVMs, with DC Link, provide bi-directional power flow between the DFIG rotor and Supply-side power supply. The Supply-side circuit senses voltage, current and DC Link voltage (VDC), and sends the sensed inputs to a Field Programmable Gate Array (FPGA), which is used to derive control of VDC so that it is maintained at 200V via SVM. The DFIG circuit senses rotor current, stator voltage, rotor speed, and rotor electrical position, which are used to derive a current reference that is used to control the rotor speed using a Proportional Integral Controller (PI). For our application we show that the DFIG rotor speed can be controlled (subsynchronous, synchronous, or supersynchronous) for a given input torque and thus distributes the power generated by the DFIG as predicted between the rotor and stator.