Doubly fed induction generators (DFIGs) are vulnerable to grid related electrical faults. Standards require DFIGs to be disconnected from the grid unless augmented with a fault ride through (FRT) capability. A fault current limiter (FCL) can enhance the overall stability of wind farms and allow them to maintain grid-code requirements. In this paper, a neuro fuzzy logic controlled parallel resonance type fault current limiter (NFLC-PRFCL) is proposed to enhance the FRT capability of the DFIG based wind farm. Theoretical and graphical analysis of the proposed method are carried out by MATLAB/Simulink software. The performance of the NFLC-PRFCL is compared with other documented FCL devices, e.g., the bridge type fault current limiter (BFCL) and the series dynamic braking resistor (SDBR). The performance of the NFLC-PRFCL is also compared with that of the existing fuzzy logic controlled parallel resonance fault current limiter (FLC-PRFCL). From the simulation results, it is found that the NFLC-PRFCL outperforms its competitors and enables the DFIG to maintain a near-seamless performance during various fault events.

High penetration of Doubly Fed Induction Generator (DFIG) into existing power grid can attribute complex issues as they are very sensitive to the grid faults. In addition, Fault Ride Through (FRT) is one of the main requirements of the grid code for integrating Wind Farms (WFs) into the power grid. In this work, to enhance the FRT capability of the DFIG based WFs, a Bridge-Type Flux Coupling Non-Superconducting Fault Current Limiter (BFC-NSFCL) is proposed. The effectiveness of the proposed BFC-NSFCL is evaluated through performance comparison with that of the Bridge-Type Fault Current Limiter (BFCL) and Series Dynamic Braking Resistor (SDBR). Moreover, a dynamic nonlinear controller is also proposed for controlling the operation of the BFC-NSFCL. Extensive simulations are carried out in the MATLAB/SIMULINK environment for both symmetrical and unsymmetrical temporary as well as permanent faults. Based on the simulation results and different numerical analysis, it is found that the proposed nonlinear controller based BFC-NSFCL is very effective in enhancing the FRT capability of the WF. Also, the BFC-NSFCL outperforms the conventional BFCL and SDBR by maintaining a near-seamless performance during various grid fault situations.

Any fault related to grid is a matter of great concern for doubly fed induction generator (DFIG) based power system as DFIGs stator windings are connected to the grid directly. To augment the transient performance of the DFIGs, superconducting fault current limiter (SFCL) is a certified device. To boost the performance of a flux-coupling-type SFCL (FC-SFCL) by ensuing the adaptive use of fault current limiting impedance based on fault severity, rather involving the full impedance unnecessarily, a nonlinear controller (NC) for FC-SFCL (NC-FC-SFCL) is presented in this paper. Reason behind choosing a straightforward NC for this work is to have simple implementation capability with the full flavor of a nonlinear controller. Effectiveness of the NC-FC-SFCL is compared with conventionally controlled FC-SFCL for various fault scenarios. Simulation results suggest that, NC-FC-SFCL can improve the overall fault ride through (FRT) capability which is verified both by graphically and numerically. Additionally, this effective use of the fault limiting impedance guarantees better transient sub-synchronous resonance (SSR) performance, and exhibits better total harmonic distortion responses.

This paper proposes a capacitive bridge-type superconducting fault current limiter (CB-SFCL) to address the most concerning issue with the grid connected hybrid power system by improving the transient performance. The hybrid system incorporates a doubly fed induction generator (DFIG) based wind farm, a solar photovoltaic (PV) system and a synchronous generator (SG) based power system. The CB-SFCL incorporates a high temperature superconductor (HTS) along with a power capacitor to provide adequate reactive power support before and after the fault. The capacitor is kept inactive during normal operation by a control circuit to ensure a seamless operation. During fault, the capacitor gets connected in series with the HTS and suppress the fault current. The performance of the CB-SFCL is investigated by proper graphical and mathematical analyses and conclusions are obtained by comparing them with that of the conventional bridge-type superconducting fault current limiter (BSFCL) and a capacitive bridge-type fault current limiter (CBFCL). The analyses support the theoretical superiority of the CB-SFCL over the BSFCL and the CBFCL by a satisfying margin.

Doubly‐fed induction generators (DFIGs) have drawn prominent interest in the field of wind power generation, but they are vulnerable to grid faults. Grid codes mandate DFIGs to employ a sort of fault ride‐through (FRT) technique during faults. Fault current limiters (FCLs) always help to augment the FRT capability of DFIGs and a non‐linear controller boosts their performances. In this study, a non‐linear auto‐regressive moving average‐L2 (NARMA‐L2) controller‐based bridge‐type flux coupling non‐superconducting FCL (BFC‐NSFCL) is proposed to enhance the FRT capability of the wind farm. The authors analysed the performance of the proposed NARMA‐L2‐based BFC‐NSFCL (NL2‐BFC‐NSFCL) against that of the conventionally used series dynamic braking resistor (SDBR), bridge‐type FCL (BFCL), and proportional–integral (PI) controller‐based BFC‐NSFCL (PI‐BFC‐NSFCL). They tested the performance of the NL2‐BFC‐NSFCL through multiple temporary and permanent fault scenarios and carried out the mathematical and graphical analysis in MATLAB/Simulink platform. They found that the proposed NL2‐BFC‐NSFCL's performance surpasses the performances of the SDBR, the BFCL, and the PI‐BFC‐NSFCL. Moreover, the NL2‐BFC‐NSFCL has faster system recovery capability after the occurrence of any fault than other competitors.