Smart Over Speed Protection of Zafarana Grid-connected Wind Farm during Wind Gust Conditions

Abstract

The increasing share of renewable energy in electricity generation requires an effective operation and protection scheme using Smart Grid (SG) technologies. Smart meters of SG allow the transfer of the measured signals in the wind farm to the operation and protection centre of the SG. Such signals transmission can improve the farm performance and reduce system cost. The secure operation of wind farms requires an efficient over speed protection of the turbines under wind gust conditions. Therefore, this paper is concerned with integration of a new over speed protection algorithm with the existing protection centre in SG. The main objective of the proposed algorithm is the dynamic updating of Critical Clearing Time (CCT) for over speed protective relays against severe wind gusts to minimize loss of life and component damage. In this respect, long-term data of wind speed of Zafarana farm have been collected and processed to define gust intensity and its distribution Moreover, the geographical farm area is classified to different rows according to the recorded gust values. A smart relay setting will be formulated by developing heuristic algorithm, which relates CCT with the gust intensity, and its row along the geographical area of Zafarana farm. Accordingly, general two variables second order function will propose to identify the dynamic CCT based on wind speed measured by smart meters installed on each wind farm row. The digital relay settings are updated according to the determined CCT using the communication facilities existing in the SG. The simulation results indicate that the proposed over speed protection improves significantly the performance of the grid connected wind farm under wind gust conditions.