多虚拟同步发电机并联系统控制参数对稳定性的影响分析

虚拟同步发电机(VSG)技术作为支撑新能源消纳的新技术,其单机运行相关问题得到了广泛探讨,但目前鲜有文献从系统层面出发来综合分析多VSG并联系统的运行特性。基于此,文中通过建立多VSG并联系统全阶模型,明晰考虑系统延时下控制参数对VSG运行特性的作用规律。首先,简析VSG的运行原理及其并联方式,指出在综合建模时需考虑线路和负载参数。然后,对VSG单机模型进行延时修正,基于此建立多VSG并联系统的全阶小信号状态空间模型。接着,采用参与度分析法,甄别不同控制参数与高、低频稳定性之间的对应关系,并通过特征值轨迹分析各参数对系统高、低频稳定性的影响趋势及阈值。最后,仿真结果验证了理论分析的正确性。

Influence Analysis of Control Parameters of Parallel System with Multiple Virtual Synchronous Generators on Stability

The virtual synchronous generator (VSG) technology is a new technology to support new energy consumption, whose related issues of single-machine operation have been widely discussed. However, few literatures are based on the system level to comprehensively analyze the operation characteristics of multi-VSG parallel system. Therefore, this paper establishes a full-order model of multi-VSG parallel system, which clearly considers the action law of control parameters on the operation characteristics of VSG with system delay. Firstly, the operation principle of VSG and its parallel mode are briefly described. It is pointed out that the comprehensive model should take the line and load parameters into account. Then, the delay of the single-machine model of VSG is corrected, and the full-order small-signal state-space model of the multi-VSG parallel system is established based on the modified model. On this basis, this paper uses the participation analysis method to clarify the correspondence between different control parameters and high-frequency and low-frequency stability. By analyzing the eigenvalue trajectory, the influence trend of each parameter on the high-frequency and low-frequency stability of the system and its threshold are analyzed. Finally, the theoretical analysis is verified by simulation.