基于MATCONT的光伏并网系统电压稳定Hopf分岔研究

光伏并网系统由于其随机性和间歇性存在着电压稳定问题.针对含光伏发电站的3节点系统模型,运用数值分岔分析软件MATCONT从有功功率和负荷无功功率两种角度进行电压稳定分岔分析,结果都显示存在Hopf分岔点,并且在分岔点处,系统受到的干扰越大,电压崩溃的时间越短.为延迟3节点系统Hopf分岔现象,在原系统中引入了线性状态反馈控制和STATCOM无功补偿控制两种分岔控制方法,并将改进后3节点系统的MATCONT仿真结果与改进前相比较,充分说明这两种方法均能有效延迟Hopf分岔,提高系统电压稳定性.同时反馈控制器的增益越大,延迟Hopf分岔现象越明显.

Study of Voltage Stability Hopf Bifurcation of Photovoltaic Grid-Connected System Based on MATCONT

Voltage stability problems arise with photovoltaic grid-connected system due to randomness and intermittence. For three-node system model with photovoltaic power plant, MATCONT, a numerical bifurcation analysis software, is used to study the voltage stability from two perspectives. The results show that there exist Hopf bifurcation points, where the larger interferences the system subjects to, the shorter time the voltage collapses. To delay the Hopf bifurcations of threenode system model, two bifurcation control methods are introduced, that is, the linear state feedback control method and STATCOM reactive power compensation control. The comparison between the improved MATCONT simulation results and those of original system indicates that the two methods can delay the Hopf bifurcation and improve voltage stability. Besides, the greater the gain of the feedback controller, the more apparent of the detention of Hopf bifurcation.