一种多时间尺度降阶原则及其在交直流电力系统中的应用

基于奇异摄动理论及矩阵特征值扰动定理，推导得出多时间尺度系统在小扰动作用下，采用忽略快动态或固定慢动态降阶时，降阶前后系统静态稳定性的一般规律，并给出一种使该稳定性规律成立的奇异摄动参数范围的计算方法，从而提出一种小扰动作用下多时间尺度系统的降阶原则，该降阶原则能保证降阶前后系统的静态稳定性一致。建立交直流电力系统中典型电力电子元件的开关周期平均奇异摄动模型，并运用所提出的降阶原则，对简单交直流电力系统进行降阶研究。降阶前、后系统在小扰动作用下的时域仿真结果证明所提出的降阶原则是有效的，能应用于交直流电力系统静态稳定性分析。

A Multi-time Scale Order Reduction Principle and Its Application in AC/DC Power System

Based on singular perturbation theory and eigenvalue perturbation theorem, steady state stability laws are derived for multi-time scale system, whose order is reduced by neglecting fast dynamics and fixing slow dynamics. To make these laws come into existence, a computational method of the bound of singular perturbation parameter is presented. Subsequently, an order reduction principle of multi-time scale system is proposed, which can ensure steady state stability consistency between original and reduced system. In order to apply this principle to AC/DC power system, the switch cycle average singular perturbation models of typical converters were made. Finally, according to the proposed reduction principle, the order of a typical AC/DC power system was reduced, and simulation results demonstrate the proposed reduction principle is effective and applicable for steady state stability analysis of AC/DC power system.