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.

Study of Reactive Power Compensation for Improvement of Low-Voltage-Ride-Through Capability of Wind Farm

2013 ◽  
Vol 724-725 ◽  
pp. 619-622 ◽  
Author(s):  
Chia Yu Hsu ◽  
Ta Hsiu Tseng ◽  
Pei Hwa Huang
Keyword(s):  
Wind Farm ◽  
Reactive Power ◽  
Low Voltage ◽  
Wind Farms ◽  
Static Synchronous Compensator ◽  
Low Voltage Ride Through ◽  
Induction Generators ◽  
Turbine Generators ◽  
Set Up ◽  
Doubly Fed

The main purpose of this paper is to study the enhancement of the Low-Voltage-Ride-Through (LVRT) capability of the wind farm with the installment of the Static Synchronous Compensator (STATCOM) and the Static Var Compensator (SVC). With more penetration of wind energy from on-shore and off-shore wind farms, utilities have been starting to set up the regulation requiring the wind turbine generators to remain connected to the grid when a fault takes place in the system which is referred to as Low-Voltage-Ride-Through (LVRT). A wind farm composed with doubly fed induction generators is used as the study system. Both the STATCOM and the SVC are utilized as the devices for enhancing the LVRT capability of the wind farm. The results are demonstrated for comparing the performance of the two devices in the improvement of voltage dynamic characteristics of the study system.

A Coherency-Based Equivalent Model of a Large Scale Wind Farm

2011 ◽  
Vol 347-353 ◽  
pp. 2342-2346
Author(s):  
Rong Fu ◽  
Bao Yun Wang ◽  
Wan Peng Sun
Keyword(s):  
Wind Power ◽  
Wind Turbines ◽  
Large Scale ◽  
Wind Farm ◽  
Dynamic Models ◽  
Wind Farms ◽  
Model Complexity ◽  
Equivalent Model ◽  
Detailed Model ◽  
Doubly Fed

With increasing installation capacity and wind farms penetration, wind power plays more important role in power systems, and the modeling of wind farms has become an interesting research topic. In this paper, a coherency-based equivalent model has been discussed for the doubly fed induction generator (DFIG). Firstly, the dynamic models of wind turbines, DFIG and the mechanisms are briefly introduced. Some existing dynamic equivalent methods such as equivalent wind model, variable speed wind turbine model, parameter identification method and modal equivalent method to be used in wind farm aggregation are discussed. Then, considering wind power fluctuations, a new equivalent model of a wind farm equipped with doubly-fed induction generators is proposed to represent the interactions of the wind farm and grid. The method proposed is based on aggregating the coherent group wind turbines into an equivalent one. Finally, the effectiveness of the equivalent model is demonstrated by comparison with the wind farm response obtained from the detailed model. The dynamic simulations show that the present model can greatly reduce the computation time and model complexity.

scholarly journals DFIG use with combined strategy in case of failure of wind farm

2020 ◽  
Vol 10 (3) ◽  
pp. 2221
Author(s):  
Azeddine Loulijat ◽  
Najib Ababssi ◽  
Mohammed Makhad
Keyword(s):  
Wind Power ◽  
Wind Turbines ◽  
Wind Farm ◽  
Reactive Power ◽  
Low Voltage ◽  
Voltage Drop ◽  
Optimal Solution ◽  
Wind Farms ◽  
Electrical Networks ◽  
Constant Frequency

In the wind power area, Doubly Fed Induction Generator (DFIG) has many advantages due to its ability to provide power to voltage and constant frequency during rotor speed changes, which provides better wind capture as compared to fixed speed wind turbines (WTs). The high sensitivity of the DFIG towards electrical faults brings up many challenges in terms of compliance with requirements imposed by the operators of electrical networks. Indeed, in case of a fault in the network, wind power stations are switched off automatically to avoid damage in wind turbines, but now the network connection requirements impose stricter regulations on wind farms in particular in terms of Low Voltage Ride through (LVRT), and network support capabilities. In order to comply with these codes, it is crucial for wind turbines to redesign advanced control, for which wind turbines must, when detecting an abnormal voltage, stay connected to provide reactive power ensuring a safe and reliable operation of the network during and after the fault. The objective of this work is to offer solutions that enable wind turbines remain connected generators, after such a significant voltage drop. We managed to make an improvement of classical control, whose effectiveness has been verified for low voltage dips. For voltage descents, we proposed protection devices as the Stator Damping Resistance (SDR) and the CROWBAR. Finally, we developed a strategy of combining the solutions, and depending on the depth of the sag, the choice of the optimal solution is performed.

Research on Voltage Stability in Grid-Connected Large Wind Farms

2011 ◽  
Vol 354-355 ◽  
pp. 989-992
Author(s):  
An Lin
Keyword(s):  
Power Systems ◽  
Voltage Stability ◽  
Wind Farm ◽  
Reactive Power ◽  
Low Voltage ◽  
Wind Farms ◽  
System Stability ◽  
Induction Generator ◽  
Induction Generators ◽  
Large Wind

Squirrel-cage induction generator (SCIG) has been widely utilized in large wind farms in China. However, the large wind farm composed of induction generators will cause obvious power system stability problems due to the dependency on reactive power. Doubly-fed induction generator (DFIG) has excellent dynamic characteristics of wind farm operations. With the increasing of wind power penetration in power systems, more and more wind farms use both SCIG and DFIG. This paper firstly analyzes the the dynamic characteristic of wind farm on power systems, especially in terms of the voltage stability. Then the interaction between the SCIGs and DFIGs is also investigated. A detailed simulation model of wind farms is presented by means of MATLAB. The simulation results demonstrate that the DFIG applications will improve the voltage stability of the wind farm largely and the low voltage ride through characteristics of SCIG to some extend.

scholarly journals Improved Low Voltage Ride Through Capability of Wind Farm using STATCOM

2021 ◽  
Author(s):  
Miad Mohaghegh Montazeri
Keyword(s):  
Wind Turbine ◽  
Wind Farm ◽  
Reactive Power ◽  
Low Voltage ◽  
Steady State Condition ◽  
Low Voltage Ride Through ◽  
Induction Generators ◽  
Turbine Generators ◽  
Wind Turbine Generators ◽  
Doubly Fed

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.

scholarly journals An Anti-Fluctuation Compensator Design and Its Control Strategy for Wind Farm System

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6413
Author(s):  
Feng-Chang Gu ◽  
Hung-Cheng Chen
Keyword(s):  
Power Control ◽  
Control Strategy ◽  
Large Scale ◽  
Wind Farm ◽  
Reactive Power ◽  
Wind Farms ◽  
Voltage Regulation ◽  
Current Control ◽  
Reactive Power Control ◽  
Control Scheme

Large-scale wind farms in commercial operations have demonstrated growing influence on the stability of an electricity network and the power quality thereof. Variations in the output power of large-scale wind farms cause voltage fluctuations in the corresponding electrical networks. To achieve low-voltage ride-through capability in a doubly fed induction generator (DFIG) during a fault event, this study proposes a real-time reactive power control strategy for effective DFIG application and a static synchronous compensator (STATCOM) for reactive power compensation. Mathematic models were developed for the DFIG and STATCOM, followed by the development of an indirect control scheme for the STATCOM based on decoupling dual-loop current control. Moreover, a real-world case study on a commercial wind farm comprising 23 DFIGs was conducted. The voltage regulation performance of the proposed reactive power control scheme against a fault event was also simulated. The simulation results revealed that enhanced fault ride-through capability and prompt recovery of the output voltage provided by a wind turbine generator could be achieved using the DFIG along with the STATCOM in the event of a three-phase short-circuit fault.

scholarly journals Improved Low Voltage Ride Through Capability of Wind Farm using STATCOM

2021 ◽  
Author(s):  
Miad Mohaghegh Montazeri
Keyword(s):  
Wind Turbine ◽  
Wind Farm ◽  
Reactive Power ◽  
Low Voltage ◽  
Steady State Condition ◽  
Low Voltage Ride Through ◽  
Induction Generators ◽  
Turbine Generators ◽  
Wind Turbine Generators ◽  
Doubly Fed

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.

Dynamic Modeling and Simulation of Doubly-Fed VSCF Wind Generator Based on PSCAD/EMTDC

2012 ◽  
Vol 608-609 ◽  
pp. 748-754
Author(s):  
Kang Yi Li ◽  
Chao Lu ◽  
Xiao Zhen Zhang ◽  
Miao Yu
Keyword(s):  
Large Scale ◽  
Wind Farm ◽  
Reactive Power ◽  
Low Voltage ◽  
Short Circuit ◽  
Implementation Process ◽  
Maximum Point ◽  
Wind Generator ◽  
Farm Model ◽  
Doubly Fed

In order to build an aggregated wind farm model to research on the effect large scale wind power has on the transient performance of the power system, firstly, it is necessary to build an effective WTGs model. Based on the electro-magnetic transient simulation platform PSCAD/EMTDC, this paper built models of all the parts of Doubly-fed type VSCF wind generator, including wind model, wind turbine model, rotation system model, detailed converters model, and emphatically expounded the implementation process of the control strategy based on the stator flux vector oriented principle. Then through the change of wind speed and setting three-phase short-circuit fault on the net side, the model is verified on the decoupling control of active and reactive power for maximum point power tracking (MPPT) and the ability of low voltage ride-through.

scholarly journals Control of DFIG Wind Turbines Based on Indirect Matrix Converters in Short Circuit Mode to Improve the LVRT Capability

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Ahmad Khajeh ◽  
Reza Ghazi
Keyword(s):  
Control System ◽  
Wind Turbines ◽  
Reactive Power ◽  
Low Voltage ◽  
Short Circuit ◽  
Electrolytic Capacitor ◽  
Dominant Type ◽  
Matrix Converters ◽  
Induction Generators ◽  
Doubly Fed

Nowadays, the doubly-fed induction generators (DFIGs) based wind turbines (WTs) are the dominant type of WTs. Traditionally, the back-to-back converters are used to excite the rotor circuit of DFIG. In this paper, an indirect matrix converter (IMC) is proposed to control the generator. Compared with back-to-back converters, IMCs have numerous advantages such as higher level of robustness, reliability, and reduced size and weight due to the absence of bulky electrolytic capacitor. According to the recent grid codes wind turbines must have low voltage ride-through (LVRT) capability. In this paper a new crowbar system is proposed so that along with the control system it protects the IMC from large fault currents and supports the grid voltage dips during grid faults. This crowbar system is provided using the existing converter switches to establish a short circuit mode without any extra circuitry. Even in severe fault conditions, the duration of short circuit mode is quite small so the control system will be activated shortly after the fault to inject reactive power as required by new LVRT standards. Therefore, the new LVRT standards are well satisfied without any extra costs. PSIM simulation results confirm the efficiency of the proposed method.

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