微电网电磁时间尺度相角稳定性分析

随着电力电子化的分布式可再生能源大规模接入电网，同步振荡和谐波失稳现象越来越受到人们的关注。相较于传统的电力系统，新型微电网更多地表现出负阻抗性、低惯性、负阻尼性和能量的双向流动性。基于此，文章提出了一种基于小信号的电磁时间尺度相角稳定性分析方法。首先，建立了电磁时间尺度电力变换器的小信号模型，通过系统相角与分布式电源无功功率的内在联系得到电力变换器的相角稳定性指标；然后，建立了电力变换器的闭环传递函数并通过特征值分析得到相角稳定域；最后，通过仿真和实验验证了所提的微电网电磁时间尺度相角稳定性分析方法。

Phase-Angle Stability Analysis of Microgrids in Electromagnetic Time Scale

With the large-scale integration of distributed renewable energy into power grid， synchronous oscillation and harmonic instability have attracted more and more attention. Compared with the traditional power system， the microgrid has plenty of characteristics， such as negative impedance， low inertia， negative damping and bidirectional power flow. Consequently， this paper proposes a phase stability analysis method based on small-signal modeling in electromagnetic time scale. Firstly， the small-signal modeling of power converter is established， and the phase stability of power converter is obtained by the inherent relationship between system phase angle and reactive power of distributed generation. Furthermore， the closed-loop transfer function of the power converter is established， and the phase stability region is obtained through eigenvalue analysis. Eventually， the proposed phase angle stability method in electromagnetic time scale is verified by simulation and experiment results.