Feedforward Transient Compensation Control for DFIG Wind Turbines During Both Balanced and Unbalanced Grid Disturbances

2013 ◽  
Vol 49 (3) ◽  
pp. 1452-1463 ◽  
Author(s):  
Jiaqi Liang ◽  
Dustin Howard ◽  
Jose Restrepo ◽  
Ronald Harley
Keyword(s):  
Low Voltage ◽  
Torque Ripple ◽  
Current Control ◽  
Control Loop ◽  
Induction Generators ◽  
Component Decomposition ◽  
Current Controller ◽  
Control Scheme ◽  
Doubly Fed ◽  
Unbalanced Grid

A feedforward transient compensation (FFTC) control scheme with proportional-integral-resonant current regulators is proposed to enhance the low-voltage ride through (LVRT) capability of doubly fed induction generators (DFIGs) during both balanced and unbalanced grid faults. Compensation for the DFIG stator transient voltage is feedforward injected into both the inner current control loop and the outer power control loop. The FFTC current controller improves the transient rotor-current control capability and minimizes the DFIG control interruptions during both balanced and unbalanced grid faults. Without the need of sequence-component decomposition, the torque ripple is reduced by injecting 60- and 120-Hz rotor-current components during unbalanced stator voltage conditions. The proposed FFTC control introduces minimal additional complexity to a regular DFIG vector-control scheme and shows promising enhancements in the LVRT capability of DFIGs. Simulation and experimental results are presented to demonstrate the effectiveness of the proposed FFTC control scheme.

A control scheme to enhance low voltage ride-through of brushless doubly-fed induction generators

Wind Energy ◽  
2015 ◽  
Vol 19 (9) ◽  
pp. 1699-1712 ◽  
Author(s):  
S. Tohidi ◽  
H. Oraee ◽  
M. R. Zolghadri ◽  
M. Rahimi
Keyword(s):  
Low Voltage ◽  
Low Voltage Ride Through ◽  
Induction Generators ◽  
Doubly Fed Induction Generators ◽  
Control Scheme ◽  
Doubly Fed

scholarly journals LVRT and Stability Enhancement of Grid-Tied Wind Farm Using DFIG-Based Wind Turbine

2021 ◽  
Vol 4 (2) ◽  
pp. 33
Author(s):  
Jannatul Mawa Akanto ◽  
Md. Rifat Hazari ◽  
Mohammad Abdul Mannan
Keyword(s):  
Wind Turbines ◽  
Large Scale ◽  
Wind Farm ◽  
Reactive Power ◽  
Low Voltage ◽  
Wind Farms ◽  
Induction Generators ◽  
Control Scheme ◽  
Wide Range ◽  
Doubly Fed

According to the grid code specifications, low voltage ride-through (LVRT) is one of the key factors for grid-tied wind farms (WFs). Since fixed-speed wind turbines with squirrel cage induction generators (FSWT-SCIGs) require an adequate quantity of reactive power throughout the transient period, conventional WF consisting of SCIG do not typically have LVRT capabilities that may cause instability in the power system. However, variable-speed wind turbines with doubly fed induction generators (VSWT-DFIGs) have an adequate amount of LVRT enhancement competency, and the active and reactive power transmitted to the grid can also be controlled. Moreover, DFIG is quite expensive because of its partial rating (AC/DC/AC) converter than SCIG. Accordingly, combined installation of both WFs could be an effective solution. Hence, this paper illustrated a new rotor-side converter (RSC) control scheme, which played a significant role in ensuring the LVRT aptitude for a wide range of hybrid WF consisting of both FSWT-SCIGs and VSWT-DFIGs. What is more, the proposed RSC controller of DFIG was configured to deliver an ample quantity of reactive power to the SCIG during the fault state to make the overall system stable. Simulation analyses were performed for both proposed and traditional controllers of RSC of the DFIG in the PSCAD/EMTDC environment to observe the proposed controller response. Overall, the presented control scheme could guarantee the LVRT aptitude of large-scale SCIG.

PIR Regulator Using DTC for DFIG during Unbalanced Grid Voltage Conditions

2014 ◽  
Vol 626 ◽  
pp. 136-140
Author(s):  
A. Ramkumar ◽  
S. Durairaj ◽  
N. Arun
Keyword(s):  
Wind Turbine ◽  
Control Strategy ◽  
Direct Torque Control ◽  
Torque Control ◽  
Grid Voltage ◽  
Induction Generators ◽  
Torque Control Strategy ◽  
Control Scheme ◽  
Doubly Fed ◽  
Unbalanced Grid

This paper presents a PIR regulator using direct torque control strategy of grid connected wind turbine driven doubly fed induction generators (DFIGs) when the grid voltage is unbalanced. Under the unbalanced grid voltage condition, the stator voltage and current quality is strongly affected due to the negative and distorted components. It will be reducing the performance of other normal loads connected to the DFIG. That control scheme consisting of indirect matrix converter using DTC. To verify the value of the proposed control strategy, simulation results with 500 MVA DFIG topology are presented and discussed in the paper. Finally,the simulation studies are carried out on a 500 MVA wind-turbine driven DFIG system under unbalanced grid voltage conditions. All the results are validated by using PSCAD simulation.

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.

Implementation of Single-Phase Two-Switch Midpoint Unidirectional Multilevel Converter System

2018 ◽  
Vol 19 (4) ◽  
Author(s):  
Peethala Rajiv Roy ◽  
P. Parthiban ◽  
B. Chitti Babu
Keyword(s):  
Single Phase ◽  
Pulse Width Modulation ◽  
Low Voltage ◽  
Supply Voltage ◽  
Harmonic Distortion ◽  
Input Voltage ◽  
Open Loop ◽  
Current Control ◽  
Control Technique ◽  
Control Scheme

Abstract This paper deals with implementation of a single-phase three level converter system under low voltage condition. The frequency of the switches is made constant and involves change in ${t_{on}}$ and ${t_{off}}$ duration. For this condition the pulse width modulation control scheme for a single phase three level rectifier is developed to improve the power quality. The hysteresis current control technique is adopted to bring forth three-level PWM on the dc side of the bridge rectifier and to achieve high power factor and low harmonic distortion. Based on the proposed control scheme, the line current is driven to follow the sinusoidal current command which is in phase with the supply voltage. By using three-level voltage pattern the blocking voltage of each power device is clamped to half of the dc link voltage. The simulation and experimental results of 20W converter under low input voltage condition are shown to verify the circuit performance. Open loop simulation and hardware tests are implemented by applying a low voltage of 15 V(rms) on the input side.

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