电网对称故障下虚拟同步机暂态稳定性分析

当电力系统遭受大干扰时,虚拟同步发电机(VSG)会与传统同步发电机一样发生暂态功角失稳现象,威胁系统稳定性。另外,电力电子器件的饱和非线性等电力电子化特征导致传统电力系统暂态稳定性的分析方法不再适用。通过以单机无穷大母线连接方式下电网发生对称短路故障为例,在借鉴传统交流电力系统分析方法的基础上提出了一种适用于电力电子化电力系统的暂态稳定性分析方法,分析了计及VSG饱和特性的暂态功角稳定性,并在此基础上提出了提高系统暂态稳定性的相应措施。最后,基于Matlab/Simulink仿真验证了结论。

The Transient Stability Analysis of the Power Grid Symmetric Fault with VSG Saturation Characteristic

The virtual synchronous generator(VSG)may occur transient angle instability as the traditional synchronous generator when the power system is seriously disturbed,which threatens the system stability.In addition,the analysis method of the traditional power system transient stability is no longer applicable due to the saturation and non-linearity characteristics of the power electronic devices.Taking the symmetrical grid fault on the single-inverter infinite-bus system as an example,a transient stability analysis method for electronic power system was proposed based on the analysis method of traditional AC power system,in which the saturation characteristic of VSG was considered.Meanwhile,the corresponding measures to improve the transient stability of the power electronic dominated system were proposed.Finally,the conclusion was verified by Matlab/Simulink simulation.