scholarly journals Control of a Variable-Impedance Fault Current Limiter to Assist Low-Voltage Ride-Through of Doubly Fed Induction Generators

Electronics ◽  
2021 ◽  
Vol 10 (19) ◽  
pp. 2364
Author(s):  
Jiejie Huang ◽  
Shun Sang ◽  
Lei Zhang ◽  
Xiaocen Xue ◽  
Tingting Sun
Keyword(s):  
Low Voltage ◽  
Fault Current ◽  
Fault Current Limiter ◽  
Low Voltage Ride Through ◽  
Induction Generators ◽  
Doubly Fed Induction Generators ◽  
Transient Electromagnetic ◽  
Current Limiter ◽  
Doubly Fed ◽  
Control Methodology

A fault current limiter (FCL) may be applied to assist the low-voltage ride-through (LVRT) of a doubly fed induction generator (DFIG). FCLs with fixed impedance, lack the flexibility to adjust their impedance to adapt to different LVRT scenarios. The direct switch-in and -out of the fixed-impedance FCL yields transient electromagnetic oscillations in the DFIG, which need to be addressed. In this paper, a variable-impedance FCL is implemented at the stator side of the DFIG to assist its LVRT, and a novel methodology is proposed to control the impedance of the FCL, with which the stator current oscillation is effectively constrained and the smooth switch-out of the FCL is realized to avoid continued active power consumption of the FCL and to restore the DFIG to its pre-fault working condition. Analysis of the LVRT transient is carried out, which lays the foundation for the control methodology to determine the impedance of the FCL based on calculation of the optimization goal. The feasibility and effectiveness of the control to the variable-impedance FCL are verified by the numerical analysis results, which compare the LVRT simulation results with the application of the fixed-impedance and the variable-impedance FCLs.

scholarly journals Design of Capacitive Bridge Fault Current Limiter for Low-Voltage Ride-Through Capacity Enrichment of Doubly Fed Induction Generator-Based Wind Farm

2021 ◽  
Vol 13 (12) ◽  
pp. 6656
Author(s):  
A. Padmaja ◽  
Allusivala Shanmukh ◽  
Siva Subrahmanyam Mendu ◽  
Ramesh Devarapalli ◽  
Javier Serrano González ◽  
...  
Keyword(s):  
Wind Farm ◽  
Reactive Power ◽  
Low Voltage ◽  
Voltage Drop ◽  
Short Circuit ◽  
Fault Current ◽  
Fault Current Limiter ◽  
Low Voltage Ride Through ◽  
Current Limiter ◽  
Doubly Fed

The increase in penetration of wind farms operating with doubly fed induction generators (DFIG) results in stability issues such as voltage dips and high short circuit currents in the case of faults. To overcome these issues, and to achieve reliable and sustainable power from an uncertain wind source, fault current limiters (FCL) are incorporated. This work focuses on limiting the short circuit current level and fulfilling the reactive power compensation of a DFIG wind farm using a capacitive bridge fault current limiter (CBFCL). To deliver sustainable wind power to the grid, a fuzzy-based CBFCL is designed for generating optimal reactive power to suppress the instantaneous voltage drop during the fault and in the recovery state. The performance of the proposed fuzzy-based CBFCL is presented under a fault condition to account for real-time conditions. The results show that the proposed fuzzy-based CBFCL offers a more effective solution for overcoming the low voltage ride through (LVRT) problem than a traditional controller.

scholarly journals Dynamic Low Voltage Ride through Detection and Mitigation in Brushless Doubly Fed Induction Generators

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4461
Author(s):  
Ahsanullah Memon ◽  
Mohd Wazir Mustafa ◽  
Muhammad Naveed Aman ◽  
Mukhtar Ullah ◽  
Tariq Kamal ◽  
...  
Keyword(s):  
Fuzzy Logic ◽  
Fuzzy Logic Controller ◽  
Low Voltage ◽  
Voltage Drop ◽  
Low Voltage Ride Through ◽  
Induction Generators ◽  
Doubly Fed Induction Generators ◽  
Reactive Current ◽  
Doubly Fed ◽  
Rotor Side Converter

Brushless doubly-fed induction generators have higher reliability, making them an attractive choice for not only offshore applications but also for remote locations. These machines are composed of two back-to-back voltage source converters: the grid side converter and the rotor side converter. The rotor side converter is typically used for reactive current control of the power winding using the control winding current. A low voltage ride through (LVRT) fault is detected using a hysterisis comparison of the power winding voltage. This approach leads to two problems, firstly, the use of only voltage to detect faults results in erroneous or slow response, and secondly, sub-optimal control of voltage drop because of static reference values for reactive current compensation. This paper solves these problems by using an analytical model of the voltage drop caused by a short circuit. Moreover, using a fuzzy logic controller, the proposed technique employs the voltage frequency in addition to the power winding voltage magnitude to detect LVRT conditions. The analytical model helps in reducing the power winding voltage drop while the fuzzy logic controller leads to better and faster detection of faults, leading to an overall faster response of the system. Simulations in Matlab/Simulink show that the proposed technique can reduce the voltage drop by up to 0.12 p.u. and result in significantly lower transients in the power winding voltage as compared to existing techniques.

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