【正文】 le generation is the future of electricity supply. Generation based on fossil fuels is not sustainable as power electricity is being consumed rapidly. On the contrary, wind power has attracted much attention as a promising renewable energy resource. It has potential benefits in curbing emissions and reducing the consumption of irreplaceable fuel reserves when the demand for power electricity has been steadily growing due to the industrial developments and the growth of the economy in most parts of the world. Wind power generation is being more and more popular while the largescale wind farm(hundreds of megawatts) is the mainstream one. During 2020, the world’s installed wind capacity reached 74 223 MW, up from 59 091 MW in 2020,which include wind energy 風力發(fā)電對電力系統(tǒng)的影響 developments in more than 70 countries around the world. The tremendous growth in 2020 shows that decision makers are starting to take seriously the benefits that wind energy development can bring. There are no technical, economic or resource barriers to supplying 12% of the world’s electricity needs with wind power alone by 2020, and this against the challenging backdrop of a projected two thirds increase of electricity demand by that date. The report is a crucial tool in the race to cut greenhouse gas emissions as 12% electricity from a total of 1 250 GW of wind power installed by 2020 will save a cumulative 10771 million tons of CO2[1]. Largescale wind farms connected to power systems have characteristics of high capacity, dynamic and stochastic performance, which challenges system security and reliability. While providing the clean power for power systems, wind farms will also bring about so me unfavorable influence on power systems. With the expansion of wind power generation and the increase of wind power ratio in a power system, the influence will likely bee the technical barriers for wind power integration. Therefore, the influence should be discussed and the countermeasures to overe these issues should be proposed. According to the issues mentioned above, this paper discusses in general terms the problems which are encountered by the developers of wind power generation projects and by utility grids when dealing with projects to integrate wind farms to power systems. Due to the characteristics of highcapacity, dynamic and stochastic performance of wind power generation, the influence includes active and reactive power flow, voltage, system stability, power quality, shortcircuit capacity, system reserve, frequency and protection. After that, corresponding countermeasures to handle these problems are remended in order to acmodate wind power generation in power systems. 1． Development situation of wind power generation From the report of the Global Wind Energy Council (GWEC), the countries with the highest total installed capacity are Germany (20 621 MW), Spain (11 615MW), the USA (11603MW), India(6270 MW) and Denmark (3 136 MW). Thirteen countries around the world can now be counted among those with over 1000 MW of wind capacity, with France and Canada reaching this threshold in 2020. shows the top 10 cumulative installed capacity of the world until December, 沈陽農(nóng)業(yè)大學學士學位論文外文翻譯 2020[2]. China started to develop wind power very late. It stepped into the stage of mercialized development and scale construction only in 1990s. Accumulated and newly added installed generating capacity over the years is shown in singleunit capacity increased from 100 kW, 200 kW, and 300 kW to 600 kW, 750 kW, and 1500 kW step by step. Fig. 1 Top 10 cumulative installed capacity of the world until December,2020 Fig. 2 Accumulative and newlyadded installed capacity of wind power in China China doubled more than its total installed capacity by installing 1 347 MW of wind energy in 2020, a 70% increase from last year’s figure. This brings China up to 2 604 MW of capacity, making it the sixth largest market world wide. the Chinese market has grown substantially in 2020, and this growth is expected to continue and speed up. According to the list of approved projects and those under construction, more than 1 500 MW will be installed in 2020. The goal for wind power in China by the end of 2020 is 5000 MW[3]. 2． Characteristics of wind power generation From the point of view of wind energy, the most striking characteristic of the wind resource is its variability. The stochastic variation of wind farms outputs root mainly in fluctuation of the wind 風力發(fā)電對電力系統(tǒng)的影響 speeds and directions. The wind is highly variable, both geographically and temporally. Furthermore this variability persists over a very wide range of scales, both in space and time. The wind speed varies continuously as a function of time and height. The time scales of wind variations are presented in as a wind frequency spectrum[4]. The turbulent peak is caused by gusts in the sub second to minute range. The diurnal peak depends on daily wind speed variations and the synoptic peak depends on changing weather patterns, which typically vary daily to weekly but include also seasonal cycles. Fig. 3 Wind spectrum farm Brookhaven based on work by van der Hoven From a power system perspective, the turbulent peak may affect the power quality of wind power generation. The influence of turbulences on power quality depends very much on the turbine technology applied. Variablespeed wind turbines, for instance, may absorb shortterm power variations by the immediate storage of energy in the rotating masses of wind turbine drive trains. That means that the power output is smoother than strongly gridcoupled turbines, fixedspeed wind turbines. Diurnal and synoptic peaks, however, may affect the longterm balancing of power system, in which wind speed forecasts plays a significant role. Another important issue is the longterm variations of the wind