Adaptive control universality of STATCOM for efficient wind energy conversion systems

Wind energy (WE) is recognized as a highly promising renewable energy source. However, its performance is significantly influenced by various grid fault events. Several adaptable and controlled devices, such as the Static Synchronous Compensator (STATCOM), have been implemented to alleviate the consequences of these faults and enhance the performance of WE systems. Control of the STATCOM poses challenges due to the limitations of static controllers, such as PI controllers. These controllers are adjusted off-line for a specific operating point and cannot be adapted to accommodate all subsequent operating points. This study introduces a model predictive control (MPC) to accomplish universality adaptive control for STATCOM coupled to a double-fed induction generator (DFIG)-based WE system. This control attempts to improve the WE system performance, protect it from damage, and keep it in continuous operation during fault events. Additionally, the objective of this study is to address various fault events that may arise within the WE system, including three-phase faults, sag/swell situations, and ferroresonance. Results showed that the proposed MPC has the potential to effectively universalize the STATCOM control in WE-DFIG systems. Thus it mitigates several faults and keeps the generator connected during different fault events regardless of any variations in the voltage profile that may occur during the faults, whether it is an increase or decrease. When comparing the MPC with the optimized PI controller, it is evident that the PI controller does not fully provide universality control for STATCOM. This is because its parameters are calculated based on specific operating conditions and stay unchanged even when they are altered.