Control and quantification of kinetic energy released by wind farms during power system frequency drops

摘要

High wind energy penetration levels in modern power systems draw attention towards wind farms expected role during frequency drops. Wind farms positive contribution required by system operators basically depends on the amount of kinetic energy stored in wind turbines rotating parts and how to manage it during frequency deviations elimination. This study presents an algorithm to estimate and control the quantity of extractable kinetic energy stored in a wind farm during frequency drops. Moreover, it manages stored kinetic energy release within a given time span to achieve positive participation in frequency drops clearance. The proposed method is based on tuning the tip speed ratio before and during the frequency drop according to several factors. The recovery time required by the wind turbine to retain its normal speed is also a function of several parameters including turbine inertia and the incoming wind speed. The proposed algorithm's impact on power system frequency is analysed by assessing the expected enhancement in frequency deviation. A hypothetical grid is considered as the benchmark including detailed modelling for wind speeds, wind turbine and wind farm to improve the creditability of the obtained results. Presented research work outcomes highlight the impact of wind farms replacement for conventional generators. Executed simulations proved that applying the proposed algorithm neutralises wind energy penetration influence on system frequency response, even more, it causes solid improvements unless the incident wind speed is too slow or the frequency drop is too high. Simulation environments are MATLAB and Simulink.