This paper presents a comparative study between the conventional PI (Proportional Integral) and backstepping controllers applied to the DFIG (Doubly Fed Induction Generator) used in WECS (Wind Energy Conversion System). These two different control strategies proposed in this work are developed to control the active and reactive power of the DFIG on the one hand, and to maintain the DC-link voltage constant for the inverting function on the other hand. This is ensured by generating control signals for two power electronic converters, RSC (Rotor Side Converter) and GSC (Grid Side Converter). In order to optimise the power production in the WT (Wind Turbine), an MPPT (Maximum Power Point Tracking) algorithm is applied along with each control technique. To simulate the effectiveness of the proposed controllers, MATLAB/Simulink Software is used, and the obtained results are analysed and discussed to compare PI and backstepping controllers in terms of robustness against wind speed variations and tracking performance in dynamic and steady states.

The advancement of ocean renewable energy through Tidal Stream Turbines (TSTs) necessitates the use of a variety of computer models to properly evaluate TST efficiency. The Doubly Fed Induction Generator (DFIG) is the most widely utilized Wind Turbine (WT) in the expanding global wind sector. Grid-tied wind energy systems often use the DFIG to meet conventional grid needs including power quality enhancement, grid stability, grid synchronization, power regulation, and fault ride-through. This paper demonstrates the design of a novel control scheme for the operation of the DFIG. The suggested control scheme consisted of an Improved Recurrent Fuzzy Neural Network (IRFNN) and Ant Colony Optimization with Genetic Algorithms (GACOs). A global control system is created and executed to monitor the changeover between the two operating modes. The plant enters a variable speed mode when the tidal speed is low enough, where the system is controlled to ensure that the turbo-generator module functions at peak power extraction efficiency for any specific tidal velocity. The findings demonstrate the system’s superior efficiency, with the highest power extraction provided despite variations in tidal stream input.

In this paper, a rotor current fault monitoring method is proposed based on a sliding mode observer. Firstly, the state-space model of the Double-Fed Induction Generator (DFIG) is constructed by vector transformation. Meanwhile, the stator voltage orientation vector control method is applied to decouple a stator and rotor currents, so as to obtain the correlation between the stator and rotor current. Furthermore, the mathematical model of stator voltage orientation is obtained. Then a state sliding mode observer (SMO) is established for the output current of the rotor of the DFIG. The stability and reachability of the system in a limited time is proved. Finally, the system state is determined by the residuals of the measured and estimated rotor currents. The simulation results show that the method proposed in this paper can effectively monitor the status: a normal state, voltage drop faults, short-circuit faults between windings, and rotor current sensor faults which have the advantages of fast response, high stability.