基于差异化减载策略的风电高占比系统全过程频率校正方法

Whole Prosess Frequency Correction Method of Wind Power High Proportion System Based on Differential Deloading Strategy

鉴于风电高占比的电力系统易遭遇频率安全事故,开展风电机组与常规机组在惯量和多层次调频下的全过程频率校正方法研究具有重要意义。为降低风资源随机性的负面影响,提出了计及不同风速下的分层式模型预测控制方法,根据捕获风速的不同将风机划入低、中、高风速区间,并根据不同风速区间风机的特性制定对应的减载策略。针对日内频率的波动,分别从不同时间尺度下惯量响应-一次调频-二次调频-三次调频的交叉耦合关系出发,建立风电-常规电源-系统三维联动的频率校正调度模型。其中,在三次调频阶段对增减出力趋势风机赋予不同的功率分配因子;在二次调频阶段引入调频收益,激励风电参与频率调整;在一次调频阶段对不同风电场风机的一次调频出力能力进行排序优选;在惯量响应阶段,考虑风机可变虚拟惯量下的电力系统惯量支撑环节。算例表明,所提方法能够提升各时间尺度风电主动参与调频的力度和精度,保障电力系统安全经济运行。

Since power systems with wind power are prone to frequency safety accidents,it is of great significance to study the frequency correction method of wind turbines and conventional generators under inertia and multilevel frequency modulations.A hierarchical model,a predictive control method,was proposed to reduce the randomness of wind resources,considering different wind speeds.According to the different captured wind speeds,the wind turbines were divided into low,medium,and high wind speed zones,and the corresponding deloading strategy was formulated in line with the characteristics of wind turbines.Aiming at the fluctuation of intraday frequency,the frequency correction scheduling model of wind power-conventional power-the system was established based on the cross-coupling relationship of inertia response-primary-secondary-third frequency regulation.In the third frequency regulation stage,wind turbines with increasing or decreasing output trends are given different power distributions.In the secondary frequency regulation stage,frequency regulation benefits are introduced to encourage wind power to participate in frequency adjustment.In the primary frequency regulation stage,the output capacity of different wind turbines is sorted and optimized.The inertia support under the variable virtual inertia is considered in the inertia response stage.The case study shows the proposed method can improve the intensity and precision of active participation in the frequency regulation of wind power at various time scales and ensure the safe and economic operation of the power system.