Tham khảo tài liệu 'from turbine to wind farms technical requirements and spin-off products part 6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 4 Frequency Control of Isolated Power System with Wind Farm by Using Flywheel Energy Storage System Rion Takahashi Kitami Institute of Technology Japan 1. Introduction For the recent expansion of renewable energy applications wind energy generation is receiving much interest all over the world. Many large wind farms have been installed so far and recently huge offshore wind farms have also been installed. However the frequency variation of power system due to wind generator output fluctuations is a serious problem. If installations of wind farms continue to increase frequency control of power system by the main sources that is hydraulic and thermal power stations will be difficult in the near future especially in an isolated power system like a small island which has weak capability of power regulation. In such a case the installation may be restricted even though it is a small wind farm. Though there is such a difficulty an introduction of the wind energy utilization is much effective in an isolated power system because main power plant in a small island is mostly a diesel engine driven generating plant and it has no good effect on the environment. Hence some strategies are necessary to improve the stability of wind farm output. According to such situations an application of battery system for the output power smoothing has been investigated so far and some experimental studies using practical facilities are being performed. The battery system is suitable for power compensation with relatively long period like load leveling. However since rapid response is necessary to compensate power variations in an isolated power system the battery system may not be appropriate because charging or discharging speed of the battery is not so fast due to its chemical process. Moreover the same capacity of electronic power converter as that of the battery power rating is required. In addition life time of battery is in general not so long and thus frequent replacement of battery .