Papers by Gilmanur Rashid
Doubly fed induction generator (DFIG) based wind farms offer some distinct advantages, but their ... more Doubly fed induction generator (DFIG) based wind farms offer some distinct advantages, but their vulnerable nature to grid fault is problematic for the stable operation of power systems with higher wind power penetration. Fault ride through (FRT) capability is a requirement imposed through the grid codes to ensure stable power system operation. A fuzzy logic controlled parallel resonance fault current limiter (FLC-PRFCL) is proposed to aid the DFIG based wind farms to achieve improved FRT capability. To check the effectiveness of the proposed FLC-PRFCL, temporary symmetric and asymmetric faults were applied to the multi-machine system, to which a DFIG based wind farm is connected. The performance of the proposed FLC-PRFCL was compared with that of the crowbar, the bridge-type fault current limiter (BFCL) and conventional proportional-integral (PI) control based PRFCL (PI-PRFCL). Simulations were performed using the Matlab/Simulink software. It was found that the proposed FLC-PRFCL is an effective device for FRT capability improvement of the DFIG based wind farm. Moreover, the proposed FLC-PRFCL outperforms the crowbar, the BFCL, and the PI-PRFCL.
High penetration of wind power into existing grid can be attributed largely to the doubly fed ind... more High penetration of wind power into existing grid can be attributed largely to the doubly fed induction generators (DFIG). However, their sensitive nature to the grid faults has created concern for their mass integration into the existing power system. The grid code has been imposed by the regulatory bodies and the transmission system operators to ensure the low voltage ride through (LVRT) capability of the wind farms for stable operation. DFIGs with their popular topology of partially rated converters are unable to provide the LVRT capability alone. In this work, a nonlinear control-based modified bridge type fault current limiter (NC-MBFCL) is proposed to enhance the LVRT capability of DFIG based wind farms. The efficacy of the NC-MBFCL is evaluated through performance comparison with that of the conventionally controlled bridge type fault current limiter (BFCL) and the modified bridge type fault current limiter (MBFCL). Extensive simulations executed in Matlab/Simulink environment for both the symmetrical and unsymmetrical faults reveal that, the proposed NC-MBFCL is very effective in enhancing the LVRT capability of DFIG based wind farms and outperforms the conventionally controlled BFCL and MBFCL. Also it was found that the BFCL demonstrates better performance than the MBFCL.
—Fault ride-through (FRT) is a common requirement to abide by grid code all over the world. In th... more —Fault ride-through (FRT) is a common requirement to abide by grid code all over the world. In this paper, to enhance the FRT capability of fixed speed wind generator system, a modified configuration of bridge-type fault current limiter (BFCL) is proposed. To check the effectiveness of the proposed BFCL, its performance is compared with that of the series dynamic braking resistor (SDBR). A harmonic performance improvement by the proposed method is also analyzed. A three-phase-to-ground (3LG) fault was applied to one of the double circuit transmission lines connected to the wind generator system. Simulation was carried out by using MATLAB/Simulink software. Simulation results show that the proposed BFCL is a very effective device to achieve the FRT and suppress fault current that eliminates the need for circuit breaker replacement. Also, the BFCL improves the harmonic performance and helps follow harmonic grid code. Moreover, it was found that the BFCL works better than the SDBR and has some distinct advantages over the SDBR. Index Terms—Bridge-type fault current limiter (BFCL), fault ride-through (FRT), fixed speed wind turbine (FSWT), grid code, series dynamic braking resistor (SDBR), total harmonic distortion (THD).
2016 IEEE/PES Transmission and Distribution Conference and Exposition (T&D), 2016
Doubly fed induction generator (DFIG) based wind generators are vulnerable to the grid faults, as... more Doubly fed induction generator (DFIG) based wind generators are vulnerable to the grid faults, as their stator windings are directly connected to the grid. Fault ride through (FRT) capability of a wind farm is very important, as it is a common requirement by the grid codes practiced all over the world. In this work, to enhance the FRT capability of a DFIG based wind farm, the parallel resonance fault current limiter (PRFCL) is proposed. To check the effectiveness of the proposed PRFCL, its performance is compared with that of the bridge-type fault current limiter (BFCL). A three-phase-to-ground (3LG) fault was applied to one of the double circuit transmission lines at the wind farm connection point of the multi-machine system to investigate the FRT capability. Simulations were carried out in Matlab/Simulink environment. Simulation results show that the PRFCL is a very effective auxiliary device to achieve better FRT. Moreover, it was found that the PRFCL outperforms the BFCL. Index Terms-Bridge-type fault current limiter (BFCL), doubly fed induction generator (DFIG), fault ride through (FRT), grid code, parallel resonance fault current limiter (PRFCL), wind farm.
IEEE Transactions on Energy Conversion, 2015
ABSTRACT Transient stability is a major concern for doubly fed induction machine (DFIM). A DFIM b... more ABSTRACT Transient stability is a major concern for doubly fed induction machine (DFIM). A DFIM based wind generator is readily affected by faults at the grid side, as it’s stator windings are interfaced to grid. However, the wind generators need to remain connected and continue operation during faults at the grid side according to the grid code requirements. Therefore it is important to enhance the transient stability of the DFIM based wind generators. To achieve enhanced transient stability of the DFIM, a bridge-type fault current limiter (BFCL) is proposed in this work. Symmetrical as well as unsymmetrical faults were applied to the test system to check the efficacy of the BFCL in transient stability enhancement. Simulations were carried out in Matlab/Simulink environment. To demonstrate the effectiveness of the proposed BFCL, its performance is compared with that of the series dynamic braking resistor (SDBR). Simulation results show that the BFCL is a very effective device to attain better stabilization of the DFIM and outperforms the SDBR in all aspects.
Power and Energy Engineering Conference, Asia-Pacific, 2011
As power system interconnections become more prevalent, there has been an increase in use of thyr... more As power system interconnections become more prevalent, there has been an increase in use of thyristor controlled shunt connected compensation devices for dynamic power compensation and enhancement of real power transmission capacity. In this paper, an enhancement technique of real power transfer capacity of transmission lines is presented. A static var compensator (SVC) is designed and applied to a simple power system for this purpose. Increase in power flow and improvement in bus voltage profile are observed after using the SVC. Stability analysis of the system after experiencing fault as well as consequent fault clearance by time domain analysis has also been performed and satisfactory results are obtained.
2014 IEEE Energy Conversion Congress and Exposition (ECCE), 2014
Doubly fed induction machine (DFIM) based wind generators are vulnerable to the grid faults, as t... more Doubly fed induction machine (DFIM) based wind generators are vulnerable to the grid faults, as their stator windings are directly connected to the grid. Besides the symmetrical faults, asymmetrical faults are also problematic to DFIM, as asymmetrical faults put turbine generator system into high electromechanical stress leading to instability and mechanical damage. There are also requirements to abide by grid
IEEE Transactions on Energy Conversion, 2000
Fault ride-through (FRT) is a common requirement to abide by grid code all over the world. In thi... more Fault ride-through (FRT) is a common requirement to abide by grid code all over the world. In this paper, to enhance the FRT capability of fixed speed wind generator system, a modified configuration of bridge-type fault current limiter (BFCL) is proposed. To check the effectiveness of the proposed BFCL, its performance is compared with that of the series dynamic braking resistor (SDBR). A harmonic performance improvement by the proposed method is also analyzed. A three-phase-to-ground (3LG) fault was applied to one of the double circuit transmission lines connected to the wind generator system. Simulation was carried out by using MATLAB/Simulink software. Simulation results show that the proposed BFCL is a very effective device to achieve the FRT and suppress fault current that eliminates the need for circuit breaker replacement. Also, the BFCL improves the harmonic performance and helps follow harmonic grid code. Moreover, it was found that the BFCL works better than the SDBR and has some distinct advantages over the SDBR.
Uploads
Papers by Gilmanur Rashid