In the current transition of power industry from conventional sources to renewable energy sources, wind power generation is becoming one of the key sources of electrical energy. Although the development of wind power plants (WPPs) has made a significant contribution to addressing the demand for clean and cheap energy, the integration of large-scale WPPs introduces a series of technical challenges to power system operations. These challenges involved control, protection, and adherence to specified power quality standards. Particularly, power quality plays a vital role in utility systems and industries having direct technical and economic impact on both power consumers and suppliers. To tackle such issues, various grid codes have been initiated by regulation authorities. Moreover, different ancillary devices and control approaches have been adopted to comply with the established grid code. This article aims to review the state-of-the-art research and progress, while considering the main challenges related to dynamic performance and power quality enhancement of emerging grid-forming wind power plants. Various topologies of wind energy conversion systems (WECSs) are examined and compared, and their control strategies are investigated. A comprehensive review on power quality and dynamic response issues caused by large-scale wind power integration is presented. Moreover, the evolving grid code requirements for grid-connected WPPs in most leading countries including Denmark, U.K., Australia, Germany, and the USA are analyzed and compared. Furthermore, the improvement approaches proposed in the literature are investigated and classified on different basis and their pros and cons are discussed. A brief discussion on the solutions and future directions is presented. Finally, some conclusive considerations about the overall study are provided.

In the current transition of power industry from non-renewable generation toward renewable-based generation, wind energy is experiencing the highest penetration among the other renewable sources. Owing to low cost and abundant availability, wind energy generation has become a promising option to address the demand of cheap and clean energy. However, the integration of diverse type of Wind Power Plants (WPP) to the existing utility grids may bring forward multiple Power Quality (PQ) challenges such as harmonics, voltage sag/swell, voltage and power imbalances, low power factor, to name but a few. To address these issues researchers have proposed various PQ compensating devices over the years which have been updated in direct proportion to fast growing advancement in the design, control and operation of wind integrated power systems. This paper essentially aims to explain and classify different PQ issues and proposed improvement techniques on the bases of their applications, configurations, capabilities, advantages, and implementation cost in detail, which can provide a base information to the researchers working in this field. Moreover, simulations have been performed to demonstrate the performance of STATCOM in enhancing the voltage of grid-connected wind power plants.

The fast-growing integration of renewable energy sources into the utility grids jeopardizes the system’s performance and stability at risk. Particularly, the increasing tendency of power electronics converters in the current renewables-based power generation and their integration to utility grids through long sub-sea cables compromises the grid strength and amplifies the risk of system instability during disturbances. To sustain grid stability and ensure effective regulation during transients, grid-following (GFL) and grid-forming (GFM) control approaches have been extensively proposed for power systems with inverter-based resources (IBRs). The former approach is solely based on a phase-locked loop (PLL) to track the phase angle of grid voltage, which reduces the system stability margin, particularly in weak-grid scenarios. Consequently, grid-forming control is increasingly recognized for its ability to maintain stability and ensure reliable operation under weak-grid conditions. Droop control is one of the most widely used grid-forming control strategies owing to its capability to emulate the behavior of synchronous machines, achieve autonomous power sharing, and ensure stable voltage and frequency regulation even under varying grid conditions. This paper aims to evaluate the impact of grid impedance and its characteristics (i.e., resistive or inductive grid impedance) on the dynamic performance of a droop control GFM grid-connected converter. To that end, first, a detailed MATLAB/Simulink model of a voltage source converter implementing the proposed droop-based GFM control is developed. Then, the overall system will be validated by performing on distinct case studies including weak and stiff power grids with inductive, resistive and nonlinear impedances in response to various grid disturbances.

The stochastic nature of wind speed and low inertia of Wind Energy Conversion Systems (WECSs) contribute to grid voltage instability, inadequate reactive power support, and increased susceptibility to grid faults. Particularly, Doubly Fed Induction Generator (DFIG)-based WECS is more perceptive to disturbances due to direct connection of its stator to grid and partially rated back-to-back converter (typically 25-30% of the generator rating). Therefore, the increasing penetration of WECSs in modern power grids necessitates robust Fault Ride-Through (FRT) capabilities to ensure stable operation during grid abnormalities. Static Synchronous Compensators (STATCOMs) offer superior FRT support through fast dynamic response and effective reactive power compensation; however, their performance degrades during deep or prolonged voltage dips due to dc-link voltage fluctuations and their inability to provide active power. To overcome these constraints, this paper proposes a coordinated control strategy for an integrated Battery Energy Storage System (BESS) and STATCOM, called BESS-STATCOM, aimed at improving the FRT capability of DFIG-based WECSs. The proposed control approach dynamically allocates reactive and active power support through coordinated operation where the STATCOM ensures rapid reactive current injection and the BESS stabilizes the dc-link voltage and provides sustained active power during extended faults. In addition, a decoupled positive and negative-sequence control scheme is developed to mitigate voltage unbalance and limit stator and rotor overcurrent during asymmetrical faults. Comprehensive simulations under diverse grid faults demonstrate that the proposed BESS–STATCOM strategy enhances system resilience, improves voltage stability, reduces generator overcurrent, and ensures grid code compliance.