虚拟同步发电机暂态全局稳定分析与阻尼调制方法

Transient Global Stability Analysis and Damping Tuning Method of Virtual Synchronous Generator

不同于传统的同步发电机,虚拟同步发电机(virtualsynchronousgenerator,VSG)的阻尼可以灵活调整,以增强系统的动态性能。首先建立了VSG系统的动态模型,基于李雅普诺夫理论导出了系统的保守稳定域。其次,基于能量守恒定律,发现阻尼耗散的能量等于阻尼因子乘以相平面中系统轨线和x轴包围的面积。研究结果表明:当每个周期内阻尼耗能大于势能变化量时,每个周期系统不稳定平衡点处的动能会单调递减,VSG系统可以实现全局稳定。由此,进一步提出了确保系统全局稳定性的阻尼调制方法。最后,基于PSCAD/EMTDC仿真分析验证了所提全局稳定条件的正确性和阻尼调制方法的有效性。

Unlike traditional synchronous generators,the damping of virtual synchronous generators(VSG)can be flexibly adjusted to enhance the dynamic performance of the system.In order to reveal the stabilization mechanism of VSG system,the global stability mechanism of VSG system considering the damping effect is analyzed.First,the dynamic model of VSG system is established,and the stable domain of the system is derived based on the Lyapunov theory.Accordingly,based on the law of conservation of energy,it is interesting to find that the energy dissipated by the damping is equal to the damping factor multiplied by the area surrounded by the system trajectory and x-axis in the phase plane.The research results show that when the dissipated energy induced by damping over one period is larger than potential energy change,the system kinetic energy will be gradually decreased until to zero,and the global stabilization can be ensured.Then,a damping tuning method to ensure the global stability of the system is further proposed.Finally,simulation studies based on PSCAD/EMTDC have validated the correctness of the proposed global stability condition and the effectiveness of the damping tuning method of VSG.