Optimal position and best switching signal of SDBR in DFIG wind turbine low voltage ride through low voltage ride through capability of Doubly Fed Induction Generators

Author(s):  
Kenneth E. Okedu
Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4461
Author(s):  
Ahsanullah Memon ◽  
Mohd Wazir Mustafa ◽  
Muhammad Naveed Aman ◽  
Mukhtar Ullah ◽  
Tariq Kamal ◽  
...  

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.


2019 ◽  
Vol 8 (2) ◽  
pp. 2882-2886

A Switch type fault current limiter in coordination with DVR is presented in this paper for Wind turbine generators that consist of doubly fed induction generators in order to full fill Low voltage ride through requirements in grid systems. The position of in-statement, the simulation and the methods for enhancement of LVRT functioning are represented. Collaborative control between the STFCL and a combination of Reactive power control and Inductance emulating control are used to enable the doubly fed induction generator to generate reactive power and ensure that the system remains safe even during faults in the grid. A different type of fault conditions are examined under both normal conditions and while the proposed system is attached.


2020 ◽  
Vol 67 (9) ◽  
pp. 7606-7616 ◽  
Author(s):  
Ailing Zhang ◽  
Zhengfang Chen ◽  
Ruozhong Gao ◽  
Jingxuan Wang ◽  
Zhizhong Ma ◽  
...  

2021 ◽  
Author(s):  
Miad Mohaghegh Montazeri

Using power electronic converters with reduced capacity in doubly-fed induction generator (DFIG) based wind turbines make them vulnerable to over-current during grid disturbances. This thesis aims to analyze the behaviour of doubly-fed induction generators based wind farm for various timing schemes of crowbar deactivation and resumption of rotor side converter (RSC) in the case of grid fault. Also, usage of a static synchronous compensator (STATCOM) for the purpose of stabilizing the grid voltage after a three-phase fault is studied in this these. Moreover, finding minimum capacity of STATCOM which ensures low-voltage ride through (LVRT) of wind farm is studied. Finally, coordination of reactive power from wind turbine generators and STATCOM in steady-state condition is performed. All the results in this thesis show that STATCOM improves low voltage ride through (LVRT) capability of wind farm and assists for an uninterrupted operation of wind turbine generators during grid faults.


In recent years, due to the interconnection of large capacity wind turbines to the power grid lead, there are serious issues in the stability of Grid and generation of electrical power. Also, it is showing effect on the dynamic performance of the electrical power systems. To maintain stability during sudden changes in the grid, the LVRT (Low Voltage Ride Through) capability of the Wind Turbines is one of the prime requirements. Wind turbines attached to DFIG (Doubly Fed Induction Generators) are advantageous which have LVRT capability at limited extent. In this paper, the elaborated discussion of the LVRT of Wind turbines shafted to DFIG's in the Grid. It also presents the complete description of the sudden changes in the systems like transient characteristics and the Doubly Fed Induction Generators dynamic response at the time of grid voltage faults (Symmetrical and Asymmetrical). The latest rotor side control technology is displayed in this paper for DFIG and wind turbines with improved capacity of low voltage ride through at the time of severe grid voltage sags. A Fuzzy Logic controller-based control technology is introduced in this paper which performs the balancing the rotor-side voltage and short circuits during the disturbances in the Grid. The advantage in this proposed control scheme is that it reduces the additional cost and reliability issues. So, the DFIG is efficient and usability company norms are satisfied with the proposed Fuzzy logic controller compared to regular controller like PI controller. The performance of the proposed system is simulated and verified in the computer. The results are displayed and it conclude that the control strategy of LVRT capability for Grid connected DFIG based wind turbine systems with Fuzzy Logic Controller are more effective than the conventional control Methods.


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