Type-2 Fuzzy Control of DFIG for Wind Energy Conversion Systems

Abstract

This study develops and designs a Type 2 fuzzy controller technique for application in
wind turbines directly linked to the grid and incorporating variable-speed doubly fed induction
generators (DFIG).
Type 2 fuzzy theory is proposed with the aim of enhancing system performance. Unlike Type 1 fuzzy
systems, it accommodates a wide range of uncertainties and dynamic nonlinearities that may
constrain the system's operational efficiency.
Type 2 fuzzy logic provides an effective approach to managing linguistic uncertainty by modeling
the ambiguity and limited reliability of information, thereby reducing the overall level of uncertainty
within the system.
Both Type 1 Fuzzy Logic Control (T1FLC) and Type 2 Fuzzy Logic Control (T2FLC)
techniques were employed in direct and indirect modes. The two control methods were
developed, their performances were evaluated, and the most effective control method in
terms of reference tracking and robustness was identified. This comparative analysis is
derived from a series of tests performed under identical conditions during both
transient and steady-state operations of the system.
The simulation results demonstrate that the proposed method exhibits significant resilience to
parameter variations and unstructured uncertainties.