电力系统主动解列断面搜索方法与孤岛调整策略

Controlled Splitting Sections Searching Method and Islanding Adjustment Strategy for Power System

主动解列是一种基于电力系统实时动态信息的紧急控制手段。及时而恰当的主动解列可以阻隔故障传播,避免保护连锁动作可能导致的系统崩溃,有利于大扰动后电力系统的快速恢复。在此背景下,提出一种包括快速搜索解列断面和优化调整孤岛的系统主动解列方案。首先,对在机器学习领域发展起来的谱聚类算法进行改进,提出含约束谱聚类算法,以计及发电机组的同调约束,从而将解列断面搜索问题转化为广义特征值求解问题。为克服在含约束谱聚类算法中采用传统k-medoids算法存在的对初始中心点敏感、搜索效率低的缺点,提出改进k-medoids算法并将其与约束谱聚类算法相结合,以求取最优解列断面。然后,对于解列后每个不满足安全约束的孤岛,优化调整其发电机组出力,必要时也可削减一些负荷,以维持每个孤岛的安全运行。最后,以IEEE 118节点系统和实际电网为例,说明所提方法的可行性和有效性。

Controlled splitting is a kind of emergency control measures with real-time dynamic information in a given power system appropriately employed. Implementation of timely and appropriate controlled splitting for a given power system under large disturbance can block the propagation of faults,and system collapse possibly caused by malfunctioning of protection devices can be avoided to some extent,and hence rapid restoration of the whole power system can be attained. Given this background,a controlled splitting method is proposed by quickly searching splitting sections and optimally adjusting the operation strategies of isolated islands. Firstly,an improved version is presented for the spectral clustering algorithm developed in the field of machine learning,and a constrained spectral clustering algorithm proposed to account for the coherent constraints of generators. The problem of searching splitting sections is then transformed into the one of finding generalized eigenvalues. Furthermore,in order to avoid the drawbacks of the traditional k-medoids algorithm that the clustering result is sensitive to the specified initial cluster centers and the search procedure is inefficient,an improved k-medoids algorithm is proposed and employed with the constrained spectral clustering algorithm to search the optimal splitting sections.In each attained island,if any security constraint is violated,adjustments of generation outputs as well as load demands can be carried out to ensure the security. Finally,the IEEE 118-bus test system and the actual power system are employed to demonstrate the feasibility and effectiveness of the proposed method.