Noncontrolled fault current limiter with reactive power support for transient stability improvement of DFIG ‐based variable speed wind generator during grid faults

Abstract

Summary According to the recent grid codes, wind turbine systems (WTSs) are required to stay connected to the grid during grid faults and provide reactive power to support the grid. Therefore, this paper proposes a noncontrolled fault current limiter (NCFCL) with reactive power support for transient stability improvement of DFIG‐based WTSs under grid faults. The proposed NCFCL is based on a nonsuperconducting reactor located in the rotor side. The NCFCL considerably limits the rotor and stator overcurrents and improves the transient stability of the doubly fed induction generator (DIFG). In addition, the proposed strategy reduces DC‐link overvoltage and electromagnetic torque oscillations and also provides reactive power to the grid to support the grid voltage recovery. In this way, the fault ride‐through (FRT) requirements of the latest grid codes can be fulfilled without affecting the DFIG stability in normal operation. Simulation studies using MATLAB/Simulink‐2019a are performed on a 2‐MW DFIG‐based WTS to confirm the effectiveness and feasibility of the proposed FRT strategy. Simulation results reveal that the proposed strategy provides better performance compared to the crowbar protection to improve the FRT capability.

Transient stability analysis of DFIG-based wind farm-integrated power system considering gearbox ratio and reactive power control

“…A control topology that integrates the robust performance of fractional order sliding mode control with the high charging/discharging rate and low maintenance requirements of super-capacitors employed in a DFIG-based wind energy system aiming at transient stability improvement [38]. Reference [39] develops a noncontrolled fault current limiter model with reactive power support in a DFIG-integrated power system to enhance transient stability based on a nonsuperconducting reactor located on the rotor side. A new RSC control method is also proposed in [40], which utilizes DFIGs to improve stability and low-voltage ride-through (LVRT).…”

Enhancing transient stability and dynamic response of wind-penetrated power systems through PSS and STATCOM cooperation

“…The transient stability of wind farms in multi-machine power systems can be enhanced using fuzzy controllers based on STATCOMs and SVCs, as demonstrated in (M. Hemeida, H. Rezk, and M. Hamada, 2018). Meanwhile, simulation results in (Fdaili et al, 2021) show that the proposed uncontrolled fault current limiter (NCFCL) with reactive power back-up is a better approach than crowbar protection for enhancing Fault Ride Through (FRT) capabilities. A method for stabilizing rotor angle is proposed in (Zheng et al, 2019), which is based on the phaseamplitude characteristics of grid transient voltage.…”