智能电网的失稳与混沌

由于智能电网含有大量的分布式新能源逆变并网,故使智能电网的潮流流向和电压分布特性发生改变,影响了智能电网的稳定性.首先建立智能电网的动态模型,采用下垂控制策略来表征新能源并网逆变器的功频特性,利用等值发电机和动态负荷模型分析智能电网的失稳过程和混沌现象.在不同的初值下,针对该模型的仿真研究表明,智能电网存在渐近稳定、周期运行、准周期运行、混沌、超混沌以及电压崩溃的运行状态.在研究过程中发现,分岔、混沌、超混沌以及电压崩溃都是智能电网失稳的中间过程.为了防止失稳事故的发生,必须在临界失稳点之前对其进行及时有效的控制.

Instability and Chaos of Smart Grid

A large number of distributed new energy incorporated in the grid through inverters is one of the characteristics of smart grid， resulting in the change of the power flow and the voltage distribution characteristics of smart grid， which will influence the stability of the smart grid. A dynamic model to analyze the process of instability and chaotic behavior of smart grid was firstly presented by using droop control strategy， equivalent generator and dynamic load model. With the simulation results， the asymptotically stable， cycle operation， quasi-periodic operation， chaos， hyperchaos and voltage collapse could be obtained under different initial conditions in smart grid. And it was found that the bifurcation， chaos， hyperchaos and voltage collapse were the middle processes of instability in smart grid. To prevent the instability accidents， the timely and effective control should be taken before the critical point.