الصفحات

Alexandria Engineeing Libraries

بحث هذه المدونة الإلكترونية

شرح طريقة تحميل الامتحانات من المدونة

الأحد، 23 مارس، 2014

Low Voltage Ride-Through Enhancement of Doubly Fed Induction Generator Using a Dynamic Voltage Restorer

Title          Low Voltage Ride-Through Enhancement of Doubly Fed Induction Generator Using a Dynamic Voltage Restorer
Author     Eman Saad Hamid El-Hawatt
Collection   Ph.D. Electric 

Abstract:  
In recent years, the total capacity of wind generation connected to the power system has been increased significantly due to its low environmental cost and low installation cost compared with other renewable energy. With the rapid increase in penetration of wind power in electric power systems, wind power systems may cause problems to system operation, such as voltage variations, grid voltage unbalance, and grid instability. Wind farms can no longer be considered as a simple energy source. Now they must have an operational behavior with several control tasks similar to those of conventional power plants. One of these control tasks, especially with doubly-fed induction generator DFIGs, is the fault ride-through capability.FRT is to keep connection of the wind power generator to the power system when power system disturbance (e.g. voltage sag and swell, over and under frequency etc.) occurs. In FRT, the case of voltage sag is called Low Voltage Ride-Through (LVRT). However, sudden voltage sag may cause unstable generator operation due to an unbalance between input power (mechanical) and output power (electrical). In order to achieve the LVRT, the stabilization of the generator and voltage recovery are needed This thesis presents LVRT method for DFIG wind turbine to protect the power converters and ride-through grid faults during grid voltage dips without disconnecting of the turbine from the grid. This limits the high rotor current and the high voltage across the DC bus. Finally the work presents a (LVRT) capability enhancement strategy of a (DFIG) using a dynamic voltage restorer (DVR). The performance of the DVR depends on its controller. The PI, PID, Fuzzy and adaptive PI using Fuzzy controller for the DVR is proposed to enhance >the LVRT capability and fulfill the grid codes without disconnecting the turbine from the grid at symmetrical grid sag voltage & unsymmetrical (single phase sag voltage) used fuzzy controller. Simulation results using Matlab are presented for a 1.5 MW DFIG with a DVR system to validate the effectiveness of the proposed control technique.

ليست هناك تعليقات:

إرسال تعليق