考虑惯量支撑及频率调节全过程的分布鲁棒机组组合

Distributed Robust Unit Commitment Considering the Whole Process of Inertia Support and Frequency Regulations

风电的随机性和低惯量增加了电力系统安全经济运行的难度。针对风电的高阶不确定性,该文提出基于正态云模型表征风电预测误差概率分布值,综合1-范数和∞-范数条件约束风电预测误差概率的可行域,建立两阶段分布鲁棒机组组合模型。同时针对高渗透率风电系统惯量低、调频能力弱的特征,在优化模型中综合考虑系统中同步发电机组的同步惯量、风电机组的虚拟惯量和下垂控制,融合时域优化和频域控制,通过时频域的解析,推导"惯量支撑–频率最低点–准稳态–二次调频"的全过程约束,以满足惯量和各阶段频率调节的备用需求。基于此,将所提模型混合整数线性化,并采用列和约束生成算法对其进行求解,生成的优化割有效地降低了求解复杂度。算例仿真验证表明,所提模型和方法能有效提升系统的频率响应能力,保证安全经济运行。

The randomness and low inertia of wind power increase the difficulty of safe and economic operation of power system. Aiming at the high-order uncertainty of wind power, a two-stage distributed robust unit commitment model was proposed, which is based on the normal cloud model to represent the probability distribution value of wind power prediction error, and combines the 1-norm and ∞-norm conditions to constrain the probability of wind power prediction error. At the same time, according to the characteristics of low inertia and weak frequency modulation ability of high permeability wind power system, the synchronous inertia of synchronous generator unit, virtual inertia and droop control of wind power unit in the system are considered in the optimization model, which integrates time-domain optimization and frequency-domain control. Through the analysis of time-frequency domain, the whole process constraint of "inertia support frequency lowest point quasi steady state secondary frequency modulation" was derived;it can meet the standby demand of inertia and frequency regulation in each stage. Based on this, the mixed integer of the proposed model was linearized, and the column and constraint generation algorithm was used to solve it. The optimal cut generated effectively reduces the complexity of the solution. The simulation results show that the proposed model and method can effectively improve the frequency response ability of the system and ensure safe and economic operation.