风电高渗透率下豫西电力系统节点频率稳定性研究

Study on Frequency Stability of Power System Under High Permeability of Wind Energy in Western Henan Province

在新能源发电渗透率迅速增长的同时,电力系统的惯性水平,尤其是频率稳定性将大幅降低。以河南豫西地区电网为研究对象,探讨不同渗透率的风电异步联网后短路故障、负荷变化及化学储能三种典型运行方式对地区电网频率的影响规律。研究发现:当短路故障运行时,随着风电渗透率的继续增加,豫西地区电网系统在应对短路故障时的系统稳定性越来越差,事故系统频率最高值及波动幅值均逐渐升高,最高可达1.35 Hz;当负荷变化运行时,随着负荷的增加,电网频率的峰谷幅值差逐渐线性升高,而随着渗透率的增加,电网频率的峰谷幅值差呈现先升高后降低的趋势,当负荷变化超过40%时对应的电网系统频率峰谷幅值差均已超过0.4 Hz;风电经化学储能后,风电并网时系统稳定性得到明显提升,短路故障运行频率变化幅值可维持在±0.005 Hz内,负荷变化时频率变化幅值可维持在±0.05 Hz内。

With the rapidly increasing proportion of new energy generation in China,the inertia level of the power system,especially the frequency stability,will be greatly reduced.Based on this,taking the West Henan power grid as the research object,the influence of three typical operation modes of wind power asynchronous interconnection with different permeability,such as short circuit fault,load change and chemical energy storage,on the frequency of regional power grid is discussed.It is found that when the short circuit fault operates,with the continuous increase of wind power penetration rate,the system stability of the power grid system in the west of Henan Province is getting worse and worse when dealing with the short circuit fault,and the maximum frequency and fluctuation amplitude of the accident system are gradually increasing,up to 1.35 Hz.When the load changes operation,the peak-to-valley amplitude difference of the grid frequency gradually increases linearly as the load increases.With the increase of permeability,the peak-valley amplitude difference of the power grid frequency shows a trend of first increasing and then decreasing.When the load change exceeds 40%,the corresponding grid system frequency peak-to-valley amplitude difference has exceeded 0.4 Hz.After the chemical energy storage of wind power,the stability of the system is significantly improved when the wind power is connected to the grid,and the amplitude of the operating frequency of short-circuit fault can be maintained within±0.005 Hz,and the amplitude of the frequency change can be maintained within±0.05 Hz when the load changes.