The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Renewable energy sources integration in power systems leaded to the development of new mandatory standards for integrated system operation. During grid faults in power supply network, wind turbines must face major challenge, imposed by strict grid codes, particularly Fault Ride — Through capability. In the event of a grid disturbance, the rotor of the wind turbine generator is susceptible to high...
This paper deals with the low voltage ride through (LVRT) capability of a wind farm comprises different arrangements of the fixed speed and variable speed turbines. Based on the grid code requirements it is seemed that the hybrid topologies can provide better performances than purely either fixed or variable speeds turbines during the fault conditions using DFIG or SCIG. In the hybrid topology two...
\n order to find a new online method to identify the rotor inter-turn short circuit fault of brushless excitation synchronous generator, this paper analyzed the changes of electromagnetic properties and electrical parameters and got the fault characteristics that field current increased and reactive power decreased after fault. The relative deviation of generator output reactive power before and after...
Functioning the hydroelectric pumped storage power plant in condenser regime for network stabilization is a common practice. During this operation, hydroelectric machines (doubly fed synchronous machine and doubly fed asynchronous machine) are influenced by various power quality perturbations causing failure to the system. This paper investigates the electro-thermomechanical effects on hydroelectric...
Doubly Fed Asynchronous Machine (DFAM) is preferred in variable speed pumped storage plants since it offers high dynamic stability and provides high efficiency in the partial load operation. In this machine, rotor side back-back power converters rated at slip power provides reactive power support to the power system without its mechanical power source through variable speed condenser action. This...
This paper presents a voltage vector control method based on space vector modulation to govern both the RSC and GSC of a wind driven DFIG during non-severe voltage conditions specially unbalanced faults. The main contribution of this work is to provide an effective voltage vector control that can mitigate problems caused by the unbalanced non-sever faults by making co-ordination between the RSC and...
Doubly-Fed Induction Generator (DFIG) Wind Turbine (WT) is rather sensitive to power system faults and requires specific power converter protection, namely a crowbar. When the crowbar is triggered, the rotor is short circuited over the crowbar impedance, the rotor-side converter (RSC) is incapacitated and therefore the DFIG operates as a squirrel-cage induction generator (SCIG) that tends to drain...
Negative impacts! of the grid faults! in the Doubly Fed Induction Generators (DFIGs) based wind turbines systems include the stator and rotor over currents, DC-link over voltage, electromagnetic torque oscillations, active and reactive power fluctuations at the grid connection point, potentially leading to destabilization of the power system network. For eliminating of the negative impacts, thus enhances...
This paper aims at the failure of wind power generation during the transmission process. The traditional rotor of the Crowbar device requires a large reactive support, which causes large fluctuations to the reactive power of the output grid while inputting and casting in the guard period. This case would influence the entire power system of power transmission. However, D-STATCOM can regulate and transmit...
Doubly-fed wind generator is highly sensitive to voltage variations of the grid, which poses limitations for wind power plants during the grid integrated operation. This paper proposes a new control strategy for rotor side converter of doubly-fed induction generator (DFIG) using energy-based control method based on Port-Control Hamiltonian (PCH) theory and L2 disturbance attenuation. The proposed...
A new control prospective is adopted in this paper to enhance the Fault Ride Through (FRT) capability of the variable speed Induction Generator along with a Crowbar protection circuit. The Induction Generator is a Doubly Fed Induction Generator (DFIG) used in a Wind Power Conversion System (WPCS). The DFIGs interconnected with the grid are very much sensitive to any disturbance in the grid. The stator...
This paper develops a control strategy for a large wind turbine based on the squirrel cage asynchronous generator (SCAG). In addition, the transient behavior during Low Voltage Ride Through (LVRT) of the system is studied. To this end, the wind turbine connected to the grid is controlled in such way to inject maximum power into the grid and provide a reactive power to regulate the grid voltage, in...
Current grid codes require DFIGs to provide voltage support during a grid fault. The fault ride-through (FRT) capability of DFIGs is the focus of this paper, in which modifications to the DFIG controller are proposed to improve the FRT capability. The static synchronous compensator (STATCOM) controller has been applied with the proposed method to study its influence on the voltage at the point of...
The number of doubly fed induction generators (DFIG) connected to the existing network has increased significantly worldwide during the last two decades. The stator in DFIG is directly connected to the grid whereas the rotor is interfaced to the grid through two voltage source converters; rotor side converter (RSC) and grid side converter (GSC), which are considered as the crux of the DFIG system...
This paper presents a simple methodology to improve the low voltage ride-through (LVRT) capability of Doubly Fed Induction Generator (DFIG) based wind turbines in order to ride through higher voltage sags and durations. The proposed method is based on selection of an appropriate value for DC side super capacitor (SC) in such a way that it could help wind turbine for LVRT without any need to crowbar...
The integration level of renewable energy resources has been continuously increasing in recent years introducing several technical challenges for utility and Independent System Operator (ISO) protection and planning engineers. One major challenge is related to the development of reliable models for system protection studies and accurate evaluation of their short circuit contributions. Converter interfaced...
Nowadays, grid code requirements demand that wind energy converters (WEC) remain connected to the grid during grid faults and contribute to the voltage support, in the same way as conventional power plants. WEC which are capable of ridding through grid faults providing voltage and reactive power support are connected to the grid via electronic power converters, increasing the failure risk and reducing...
Wind energy conversion systems contribute a significant fraction of total electric power generation from renewable energy based systems. Since several decades, Squirrel Cage Induction Generator (SCIG) has been considered as the backbone of wind power industry. The concept of dynamic reactive power compensation of induction generator based wind farms is gaining paramount importance because of the formation...
Power system stability issues are extremely important for safe and effective operation of the system. They can be categorized as rotor angle, frequency and voltage stability issues. Grid connection of new generators can have significant impact on overall system performance and stability. This paper presents investigation of a wind farm transient stability under symmetrical three phase fault conditions...
This paper presents application of fuzzy logic control for Reactive Power and D.C capacitor voltage control of Doubly Fed Induction Generator (DFIG) during external faults. In order to apply fuzzy logic controller, a model is developed in MATLAB/SIMULINK. Reactive power is control from rotor side converter and d.c. capacitor voltage is control from grid side converter. The simulation results are presented...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.