考虑风速波动性的海上风电渗透率极限评估方法

The Method for Assessing the Maximum Penetration Rate of Offshore Wind Power Considering Wind Speed Variability

大规模具有间歇性、波动性且难以预测的风电接入电网后会给电网的电压和频率稳定性带来一系列挑战,因此如何评估已有区域电网的最大风电极限渗透功率成为了一个重要问题。现有研究大多分析了不同风电渗透率对电网电压和频率稳定性的影响,而缺乏对海上风电渗透率极限的评估。为此,考虑风速波动性的影响,提出了一种针对已有区域电网的海上风电渗透率极限评估方法。首先,通过研究海上风电场静态模型分析海上风电场功率输出特性;然后,通过构建含海上风电场和同步发电机的电网等效模型分析不同风电渗透率下并网点(Point of Common Coupling, PCC)电压与频率特性;最后,针对风速波动引起的电网电压和频率波动,提出考虑风速波动性的海上风电渗透率极限评估方法,并通过算例验证所提方法的有效性。随着海上风电渗透率增加,PCC电压降低速度和幅度也增大,加剧了有功波动对PCC电压的不利影响。此外,高渗透率条件下,电力系统可能面临有功功率缺额问题,造成频率偏差加剧。电压闪变和电压偏差在高渗透率时也随之增加,导致电能质量下降,频率合格率降低。

The large-scale integration of intermittent,fluctuating and inherently unpredictable wind energy into the power grid poses a series of challenges to the stability of grid voltage and frequency.Consequently,evaluating the maximum wind energy penetration capacity of existing regional grids has become a significant concern.Current research predominantly analyzes the impact of different wind energy penetration rates on grid voltage and frequency stability,yet lacks an assessment of the ultimate penetration limit for offshore wind energy.To address this gap,a method for evaluating the ultimate penetration limit of offshore wind energy in existing regional grids is proposed after taking into account the influence of wind speed variability.Firstly,the power output characteristics of offshore wind farms are analyzed through a static model of offshore wind fields.Subsequently,by constructing an equivalent grid model that incorporates offshore wind farms and synchronous generators,the voltage and frequency characteristics at Point of Common Coupling(PCC)are analyzed for various wind energy penetration rates.Lastly,considering the grid voltage and frequency fluctuations induced by wind speed variability,a method accounting for wind speed fluctuations is proposed for assessing the ultimate penetration limit of offshore wind energy.The effectiveness of the proposed method is validated through numerical examples.As the offshore wind power penetration rate increases,the rate and magnitude of PCC voltage reduction also increase,exacerbating the adverse effects of active power fluctuations on PCC voltage.In addition,under high penetration conditions,the power system may face active power shortage issues,leading to intensified frequency deviations.Meanwhile,voltage flicker and voltage deviations also increase with high penetration rates,causing a decline in power quality and reducing the frequency compliance rate.