基于交替方向乘子法的分布式负荷频率控制策略

负荷频率控制(load frequency control, LFC)是维持电力系统安全稳定运行的基础。对于多区域互联电力系统,由于描述动态过程的微分方程组相当复杂,这给负荷频率控制器的设计带来了困难。在此背景下,针对多区域互联电力系统,提出基于交替方向乘子法 (alternating direction method of multiplier, ADMM) 的分布式最优负荷频率控制器设计方法,以取得良好的控制性能,同时具备较高的计算效率。首先,介绍了负荷频率控制问题的微分方程模型。之后,基于二次多项式和矩阵稀疏化构建了分布式最优LFC策略的数学模型,并采用ADMM求解。最后,以三区域互联电力系统为例对所提方法进行了验证。仿真结果表明,针对负荷扰动和时变参数,所提方法能够把各区域的频率偏差和区域间联络线上的功率偏差控制到0。

Distributed Optimal Load Frequency Control Strategy Based on Alternating Direction Method of Multiplier

Load frequency control (LFC) is essential for maintaining the security and stability of the power system concerned. However, the complexity of the differential equation model characterizing the dynamics of an interconnected power system brings a challenge to the design of the load frequency controller. Given this background, a distributed optimal control scheme based on alternating direction method of multiplier (ADMM) is employed to design the load frequency controller for the interconnected power system. The proposed approach can simultaneously optimize the control performance and improve the computation efficiency. Firstly, the mathematical model of LFC is briefed. Then an optimization formulation for designing the distributed optimal control scheme of LFC is presented on the basis of the quadratic performance and matrix sparsification, and solved by using ADMM. Finally, a three-area interconnected power system is employed to demonstrate the feasibility and effectiveness of the proposed LFC approach.