相域恒阻抗同步电机移频电磁暂态建模与仿真

Modeling of Synchronous Machine in Phase Domain With Constant Inner Impedance Based on Frequency Shifting Theory

同步电机是电力系统中重要的发电设备,其暂态模型是否准确直接影响系统仿真精度。为满足电力系统低频-高频不同速率暂态过程准确、快速仿真的需求,提出了相域恒阻抗同步电机移频电磁暂态仿真模型。首先,基于希尔伯特变换与坐标变换,采用解析信号重构了同步电机方程。引入移频变换,建立了离散化的诺顿电路等效暂态仿真模型。模型具有直接的机网接口。进一步通过添加额外的虚拟绕组并提出虚拟绕组参数设置方法,使电机模型导纳矩阵为恒导纳矩阵,避免了每个时间步长需更新系统导纳矩阵的问题。所提出的电机模型通过设置不同的时间步长、移动频率、虚拟绕组参数,能够同时实现准确的高频暂态过程仿真和高效的低频暂态过程仿真。最终,通过与传统电磁暂态仿真模型的对比,验证了所提出相域模型的准确性与高效性。

As the principal source of the electric energy in power systems,the modeling of the synchronous machine for transient analysis has always been an active topic of research.In this paper,a new synchronous machine model for the simulation of multi-scale transients is developed in the phase domain.Based on the Hilbert transform and the reference frame transformation,the machine equations are reconstructed through the analytic signals.The shift frequency appears as a new simulation parameter in addition to the time-step size.By adding an artificial damper winding,a constant machine admittance matrix is formed.The proposed model provides a direct network-machine interface.Through appropriate selection of time step size,shift frequency,and artificial winding parameters,the proposed model supports accurate and efficient simulations for both the high-frequency and low-frequency transients within a simulation run.The proposed model is compared with traditional electromagnetic transients program(EMTP)type models.Case studies demonstrate the effectiveness of the proposed machine model in terms of accuracy and efficiency.