Techniques for Ensuring Fault Ride-Through Capability of Grid Connected DFIG-Based Wind Turbine Systems: A Review

Abstract

Renewable energy sources (RES) are being integrated to electrical grid to complement the conventional sources to meet up with global electrical energy demand. Among other RES, Wind Energy Conversion Systems (WECS) with Doubly Fed Induction Generator (DFIG) have gained global electricity market competitiveness because of the flexible regulation of active and reactive power, higher power quality, variable speed operation, four quadrant converter operation and better dynamic performance. Grid connected DFIG-based WECS are prone to disturbances in the network because of direct connection of stator windings to grid. The ability of the Wind Turbine (WT) to remain connected during grid faults is termed the Fault Ride-Through (FRT) capability. The grid code requirement for integrating the DFIG-based WTs to power networks specified that they must remain connected and support the grid stability during grid disturbances of up to 1500 ms. The use of compensation devices offers the best FRT compliance thereby protecting the DFIG and the converters from voltage fluctuations and over currents during the grid fault. The paper presents a review of techniques employed in ensuring FRT compliance. The article also proposes the state-of-the-art techniques for compensating voltage sag/swell and limiting the fault short-circuit current.
 Keywords: Renewable energy sources, DFIG, wind turbine system, fault ride-through, grid codes, dual-functional DVR

Control Strategies of DFIG Technology-based Variable-Speed Wind Turbines-A Review

“…According to Shuaibu, M. et al (2021) [39], the electrical grid is incorporating renewable energy sources (RES) as a supplement to conventional sources and to meet the rising demand for electrical energy globally. Grid connected DFIG-based WECS are subject to network interruptions since the windings of the stator and grid are directly interconnected.…”

Wind energy conversion technologies and engineering approaches to enhancing wind power generation: A review

“… [ 98 ] Compensating voltage swell by limiting the fault short circuit current through the application of dynamic voltage resistor (DVR)-FLC technique in ensuring to develop robust system of enhanced power quality. [ 99 ] Improving power reliability Reducing the model complexity of different DFIG-turbine systems by making use of the novel model reduction margin (MRM) as optimization strategy and the New England test system (NETS) as evaluation model; while evaluating the damping torque contribution to stability margin from the dynamic model components of these systems. [ 100 ] Employing an enhanced primary frequency response (PFR) strategy so as to reduce the pitch angle to slowly feed the active power to the grid system in improving the frequency stability of the system.…”

“…For instance, the power quality of the grid connected DFIG system was considered to be enhanced by employing low voltage ride through (LVRT) strategy that was developed as capacitor-inductor series connection and capacitor/inductor-resistor parallel connection [ 95 ]; the impact of rotor current attenuation process on the DFIG system components and power stability was studied based on the real-time data service (RTDS) and physical controller in enabling the enhancement of power quality and power devices protection [ 96 ]. In addition, non-superconducting fault current limiter that was based on bridge-type flux coupling method [ 97 ]; external retrofit and internal control techniques [ 98 ]; and dynamic voltage resistor (DVR)-FLC technique [ 99 ] were also proposed to enhance FRT capability based on the modeling of DFIG system components. Moreover, the power reliability with DFIG system operations was reported to be improved based on the implementation of different research modeling strategies including: a novel model reduction margin (MRM) & New England test system (NETS) [ 100 ]; an enhanced primary frequency response (PFR) [ 101 ]; etc.…”

Fuzzy-Based EV Charging Station and DVR-Fed Voltage Compensation for a DFIG-Fed Wind Energy System during Grid Faults

“…Sardar Kamil et al [13] reviewed the several control strategies for maintaining the low voltage ride through (LVRT) capability of grid-feeding converters, with their benefits and drawbacks, thereby presenting a comparative listing of various current control loops where vector control is chosen as the primary control with various rotor parameters as reference. In [14], stator flux orientation and Lyapunov theory are proposed as an LVRT solution with an enhanced control technique of stator powers exchanged between the DFIG and the grid. Geng et al developed control strategies with grid side converters (GSCs) for unsymmetrical faults in grid integrated wind systems [15,16].…”