随着大规模可再生能源发电接入电网，电力系统运行调控的挑战逐渐凸显。高比例可再生能源电力系统所存在的频率和电压调节能力不足问题，很大程度上归因于可再生能源缺乏主动参与电力系统运行控制的能力。而可再生能源发电分布广、单体容量小、波动性强、动态特性复杂，如何实现主动控制，在控制架构和算法方面都面临重大挑战。本论文以高比例可再生能源电力系统的分布式集群控制方法为研究主题，构建以分布式集群控制为核心的控制方法体系，为解决高比例可再生能源电力系统的安全、经济运行问题提供可行的调控手段。在基础方法层面，本论文研究了分布式集群控制架构与高效求解算法。首先采用分层自律控制思路，利用反馈优化模式，提出了基于分解协调的分布式集群控制架构，旨在同时实现集群内部的协调优化和集群对外友好并网特性。随后介绍了基于矩阵分块的分布式拟牛顿法，并在矩阵分裂理论的基础上，改进提出了基于内环递推的分布式牛顿法，解决了海森矩阵求逆与分布式求解之间的矛盾，提供超线性的收敛速度，满足大规模可再生能源发电集群在线控制的需求。在应用场景层面，本论文首先研究了风电场集群的并网频率控制方法。建立了考虑风机间功率分配的风电场集群并网频率控制模型，给出了风机能量状态评价指标，设计了风电场集群并网频率控制架构。针对频率控制优化模型，提出了基于分布式牛顿法的风电场集群并网频率控制优化算法，快速协调大量风机，实现优化模型的高效分布式求解，使得风电场集群整体对外提供频率和惯性支撑。随后研究了分布式光伏集群的并网电压控制方法。采用分布式集群控制架构，建立了考虑三相不平衡注入的分布式光伏集群电压控制模型，实现了三相模型的线性化近似。针对电压控制问题，提出了适应三相潮流模型的分布式光伏集群电压控制优化算法，通过调节光伏无功，优化集群电压分布。提出了适合在线应用的分布式光伏集群并网动态电压控制方法，为系统电压提供有效的动态支撑。最后研究了孤立可再生能源发电集群的分布式运行控制方法。建立了分布式电源的统一成本函数，为集群功率的最优分配提供基础。提出了交流孤立集群的分布式频率控制方法，在频率控制的同时实现了发电成本的优化。提出了直流孤立集群的分布式电压控制方法，保证了直流孤立集群中母线电压的稳定和最优经济运行。
With the increasing installation of large-scale renewable generation to power systems, operation and control challenges have drawn much attention. The shortage of frequency and voltage regulation capability of power systems with high penetration of renewable generation can attribute to that the existing operation and control methods are unable to cope with the active control problem of large-scale renewable generation. Due to the scattered distribution, small capacity, high uncertainty and complex dynamics of renewable generation, the control architecture and algorithm of power systems with high penetration of renewable generation encounter with serious challenges. This dissertation focuses on the theme of distributed cluster control method for power systems with high penetration of renewable generation, constructs an optimal control methodology for the power systems based on distributed cluster control, and provides a feasible way to tackle stability and economic issues of power systems with high penetration of renewable generation.From the method perspective, a distributed cluster control architecture and efficient algorithms are studied. Based on hierarchical autonoumous control and using feedback optimization mode, a distributed cluster control architecture is proposed, which aims to realize inner-cluster cooperative optimization and friendly outer charateristics in the meantime. Besides, a distributed quasi-Newton method based on matrix partitioning is introduced, and a distributed Newton method based on inner-loop recursion is proposed, using matrix splitting method. The proposed method solves the contradiction between inverse of Hessian matrix and distributed implementation, exhibits a super-linear convergence, and satisfies the requirement of real-time conrol for large-scale distributed renewable generation clusters.From the application perspective, the dissertation firstly studies frequency control method for grid-connected wind farm clusters. A frequency control model for grid-connected wind farm cluster considering power distribution among wind turbines is given. By introducing an index of state of energy, we design a wind farm cluster control architecture. To solve the optimization model of frequency control, the dissertation proposes a frequency control algorithm for wind farm clusters based on distributed Newton method, which can cooperate wind turbines and solve the optimization model efficiently. By adopting to the proposed control architecture and algorithm, a wind farm can provide inertia and frequency support to external systems as a whole.Secondly, the dissertation studies voltage control method for grid-connected distributed PV clusters. Combined with distributed cluster control control architecture, an online dynamic voltage control scheme for distributed PV cluster is proposed. A voltage control model for distributed PV clusters considering three-phase unbalanced power injection is developed, which realizes linear approximation of three-phase model. In order to solve the voltage control problem, we proposes a voltage control algorithm for distributed PV clusters based on three-phase power flow model. By regulating reactive power of PV inverters, the method can improve voltage profile of PV clusters.Finally, the dissertation studies distributed control method for islanded renewable generation clusters. A unified generation cost function is given as the basis of optimal power distribution. For AC islanded clusters, the dissertation proposes a distributed frequency control method and realizes minimum generation cost during frequency control process. For DC islanded clusters, the dissertation proposes a distributed voltage control method and guarantees the stability of DC bus voltage in islanded clusters.
