Hierarchical and Distributed Monitoring and Conrol Methods of Small-Signal Stability of Large-Scale Power System

本课题对大型电力系统小信号稳定性的分层分布式监测与控制方法进行了基础研究。首先，我们提出了一种新的特征值监测和控制方案，该方案在每个局部控制站监测和稳定整个系统划分成的每个局部系统的特征值，并利用从每个局部控制站传输的本地信息在中央控制站监测和稳定互连系统的缩减尺寸的特征值。改进了我们以前开发的特征值控制方法，使其在分层分布式控制方案中具有稳定的特征值。其次，提出了一种新的适用于上述监控方案的大规模网络分解方法，该方法利用模拟退火方法对整个系统进行划分，使每个局部系统的特征值的局部模态和全局模态得到明显分离，同时考虑到所提出的监控计算的并行处理。第三，我们开发了一种基于本地系统识别的在线自适应PSS（电力系统稳定器），它能很好地适应各种潮流条件和网络配置。该方法利用局部系统中发电机的实测数据在线估计包含P55的局部系统状态方程的系统矩阵，然后在线改变P55的增益和时间常数等控制参数，从而稳定局部系统矩阵的特征值。结果表明，当所提出的分布式发电机控制方案安装在多个不同本地系统的多个发电机上时，该分布式发电机控制方案可以很好地稳定互联系统。

In this project, a fundamental study has been done on a hierarchical and distributed monitoring and control method for small-signal stability in a large-scale power system. First, we propose a new eigenvalue monitoring and control scheme, where eigenvalues of each local system into which the whole system is divided are monitored and stabilized in each local control station and eigenvalues of the reduced size of the interconnected system are monitored and stabilized in central control station using local information transferred from each local control station. Eigenvalue control method which was developed by us before is modified for stabilization of eigenvalues in this hierarchical and distributed control scheme. Second, a new large-scale network decomposition method suited for the above monitoring and control scheme is proposed, where simulated annealing method is applied to divide the whole system so that local-mode ones and global-mode ones of eigenvalues in each local system are separated clearly taking into accout parallel processing of the proposed monitoring and control calculation. Third, we develop an online adaptive PSS (Power System Stabilizer) based on local system identification using local information, which works well for various kinds of load flow conditions and network configurations. In the proposed PSS, system matrix of the state equation of a local system where the P55 is included is estimated online by using measured data on generators in the local system and then control parameters of the P55 such as gains and time constants are changed online so that eigenvalues of the local system matrix are stabilized. It is made clear that when the proposed PSSs are installed into several generators which are located in several different local systems, the interconnected system can be well-stabilized by this distributed generator control scheme.