基于矢量裕度法的风电并网对低频振荡模式影响分析

近年来可再生能源发电装机容量的持续性增长给电力系统稳定性带来新的问题。文中提出一种基于频率响应矩阵计算风电并网对电力系统低频振荡模式影响的方法。分析结果表明,同步电网和风电机组系统频率响应矩阵部分元素的相位之和,决定了系统不同接入点风电对低频振荡模式的影响。相较于传统的分析方法,矢量裕度法不需求取特征向量和留数,只需得到低频振荡模式和风电机组系统与同步电网系统的传递函数矩阵,且过程简单,结果直观。当多台风电机组同时并入系统时,可在二维复平面将各台机组分别产生的影响图示化。分析结果的有效性通过内蒙古电网算例得到验证。

Analysis of Influence of Wind Power Grid Connection on Low-frequency Oscillation Mode Based on Vector Margin Method

In recent years, the continuous growth of the installed capacity of renewable energy generation has brought new problems to the stability of power systems. An analysis method based on the frequency response matrix is proposed to calculate the influence of wind power grid connection on the low-frequency oscillation mode in power systems. The result shows that the phase sum of some elements in the frequency response matrix of the synchronous grid and wind turbine system determines the influence of wind power at different access points on the low-frequency oscillation mode. Compared with the traditional analysis method, the vector margin method only needs to obtain the low-frequency oscillation mode and the transfer function matrix of the wind turbine system and synchronous grid system without the necessity of calculation of eigenvectors and residue. The process is simple and the result is intuitive. When multiple wind turbines are integrated to the system simultaneously, the influence of each wind turbine can be observed visually in a two-dimension complex plane. The effectiveness of the analysis results can be verified by the case of Inner Mongolia grid in China.