不同运行方式的大规模新能源接入电网后的调频特性研究

Study on frequency regulation characteristics of power grids after large-scale new energy integration under different operation modes

给出了双馈风力发电机(doubly-fed induction generator,DFIG)参与电网调频的基本数学模型,推导出了大规模风电接入电网后,在不同运行方式(如惯性控制或者最大功率跟踪)下风电功率的渗透率、可调频风电机组所占比例以及风电机组的频率调节系数等与风电利用率之间的关系,提出了不同运行方式的风电机组参与电网调频的控制策略。以南方某片区电网为例,分析了风速改变及负荷变化的情况下风电功率注入比例对接入电网调频的影响特征,验证了可调频新能源发电对电网调频作用的有效性。将可调频风电机组接入4机2区域的电网模型,给出风电注入比例不同情况下所需要的可调频风机所占比例最小值及电网对新能源的综合承载能力。仿真结果表明,大规模风电场参与调频时应尽可能使运行在额定风速附近的机组参与调频,从而最大程度确保电网的频率偏差变小,维持频率在安全运行范围内。

The basic mathematical model of doubly-fed induction generator(DFIG)participating in grid frequency regulation is presented.The relationship between wind power penetration,the proportion of wind turbines with adjustable frequency ability,the frequency regulation coefficient of wind turbines,and wind power utilization is derived under different operating modes(such as inertia control or maximum power tracking)after large-scale wind power is connected to the grid.The control strategies for wind turbines to participate in grid frequency regulation under different operating modes are proposed.Taking a grid in southern China as an example,the impact characteristics of wind power injection ratio on grid frequency regulation under changing wind speed and load conditions are analyzed,and the effectiveness of renewable energy generation with adjustable frequency ability in grid frequency regulation is verified.By connecting wind turbines with adjustable frequency ability to a 4-machine 2-area grid model,the minimum proportion of required wind turbines and the comprehensive carrying capacity of the grid for renewable energy under different wind power injection ratios are presented.Simulation results show that when large-scale wind farms participate in frequency regulation,it is advisable to involve turbines operating near rated wind speed to minimize grid frequency deviation and maintain frequency within the safe operating range.